/* Copyright (c) 2013-2017, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * 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.
 *
 * UFS debugfs - add debugfs interface to the ufshcd.
 * This is currently used for statistics collection and exporting from the
 * UFS driver.
 * This infrastructure can be used for debugging or direct tweaking
 * of the driver from userspace.
 *
 */

#include <linux/random.h>
#include "ufs-debugfs.h"
#include "unipro.h"
#include "ufshci.h"

enum field_width {
	BYTE	= 1,
	WORD	= 2,
};

struct desc_field_offset {
	char *name;
	int offset;
	enum field_width width_byte;
};

#define UFS_ERR_STATS_PRINT(file, error_index, string, error_seen)	\
	do {								\
		if (err_stats[error_index]) {				\
			seq_printf(file, string,			\
					err_stats[error_index]);	\
			error_seen = true;				\
		}							\
	} while (0)

#define DOORBELL_CLR_TOUT_US	(1000 * 1000) /* 1 sec */

#ifdef CONFIG_UFS_FAULT_INJECTION

#define INJECT_COMMAND_HANG (0x0)

static DECLARE_FAULT_ATTR(fail_default_attr);
static char *fail_request;
module_param(fail_request, charp, 0);

/**
 * struct ufsdbg_err_scenario - error scenario use case
 * @name: the name of the error scenario
 * @err_code_arr: error codes array for this error scenario
 * @num_err_codes: number of error codes in err_code_arr
 */
struct ufsdbg_err_scenario {
	const char *name;
	const int *err_code_arr;
	u32 num_err_codes;
	u32 num_err_injected;
};

/*
 * the following static arrays are aggregation of possible errors
 * that might occur during the relevant error scenario
 */
static const int err_inject_intr_err_codes[] = {
	CONTROLLER_FATAL_ERROR,
	SYSTEM_BUS_FATAL_ERROR,
	INJECT_COMMAND_HANG,
};

static const int err_inject_pwr_change_err_codes[] = {
	-EIO,
	-ETIMEDOUT,
	-1,
	PWR_REMOTE,
	PWR_BUSY,
	PWR_ERROR_CAP,
	PWR_FATAL_ERROR,
};

static const int err_inject_uic_err_codes[] = {
	-EIO,
	-ETIMEDOUT,
};

static const int err_inject_dme_attr_err_codes[] = {
	/* an invalid DME attribute for host and device */
	0x1600,
};

static const int err_inject_query_err_codes[] = {
	/* an invalid idn for flag/attribute/descriptor query request */
	0xFF,
};

static struct ufsdbg_err_scenario err_scen_arr[] = {
	{
		"ERR_INJECT_INTR",
		err_inject_intr_err_codes,
		ARRAY_SIZE(err_inject_intr_err_codes),
	},
	{
		"ERR_INJECT_PWR_CHANGE",
		err_inject_pwr_change_err_codes,
		ARRAY_SIZE(err_inject_pwr_change_err_codes),
	},
	{
		"ERR_INJECT_UIC",
		err_inject_uic_err_codes,
		ARRAY_SIZE(err_inject_uic_err_codes),
	},
	{
		"ERR_INJECT_DME_ATTR",
		err_inject_dme_attr_err_codes,
		ARRAY_SIZE(err_inject_dme_attr_err_codes),
	},
	{
		"ERR_INJECT_QUERY",
		err_inject_query_err_codes,
		ARRAY_SIZE(err_inject_query_err_codes),
	},
};

static bool inject_fatal_err_tr(struct ufs_hba *hba, u8 ocs_err)
{
	int tag;

	tag = find_first_bit(&hba->outstanding_reqs, hba->nutrs);
	if (tag == hba->nutrs)
		return 0;

	ufshcd_writel(hba, ~(1 << tag), REG_UTP_TRANSFER_REQ_LIST_CLEAR);
	(&hba->lrb[tag])->utr_descriptor_ptr->header.dword_2 =
							cpu_to_be32(ocs_err);

	/* fatal error injected */
	return 1;
}

static bool inject_fatal_err_tm(struct ufs_hba *hba, u8 ocs_err)
{
	int tag;

	tag = find_first_bit(&hba->outstanding_tasks, hba->nutmrs);
	if (tag == hba->nutmrs)
		return 0;

	ufshcd_writel(hba, ~(1 << tag), REG_UTP_TASK_REQ_LIST_CLEAR);
	(&hba->utmrdl_base_addr[tag])->header.dword_2 =
						cpu_to_be32(ocs_err);

	/* fatal error injected */
	return 1;
}

static bool inject_cmd_hang_tr(struct ufs_hba *hba)
{
	int tag;

	tag = find_first_bit(&hba->outstanding_reqs, hba->nutrs);
	if (tag == hba->nutrs)
		return 0;

	__clear_bit(tag, &hba->outstanding_reqs);
	hba->lrb[tag].cmd = NULL;
	__clear_bit(tag, &hba->lrb_in_use);

	/* command hang injected */
	return 1;
}

static int inject_cmd_hang_tm(struct ufs_hba *hba)
{
	int tag;

	tag = find_first_bit(&hba->outstanding_tasks, hba->nutmrs);
	if (tag == hba->nutmrs)
		return 0;

	__clear_bit(tag, &hba->outstanding_tasks);
	__clear_bit(tag, &hba->tm_slots_in_use);

	/* command hang injected */
	return 1;
}

static void
ufsdbg_intr_fail_request(struct ufs_hba *hba, u32 *intr_status)
{
	u8 ocs_err;

	dev_info(hba->dev, "%s: fault-inject error: 0x%x\n",
			__func__, *intr_status);

	switch (*intr_status) {
	case CONTROLLER_FATAL_ERROR: /* fall through */
		ocs_err = OCS_FATAL_ERROR;
		goto set_ocs;
	case SYSTEM_BUS_FATAL_ERROR:
		ocs_err = OCS_INVALID_CMD_TABLE_ATTR;
set_ocs:
		if (!inject_fatal_err_tr(hba, ocs_err))
			if (!inject_fatal_err_tm(hba, ocs_err))
				goto out;
		break;
	case INJECT_COMMAND_HANG:
		if (!inject_cmd_hang_tr(hba))
			inject_cmd_hang_tm(hba);
		break;
	default:
		BUG();
		/* some configurations ignore panics caused by BUG() */
		break;
	}
out:
	return;
}

static bool
ufsdbg_find_err_code(enum ufsdbg_err_inject_scenario usecase,
		     int *ret, u32 *index)
{
	struct ufsdbg_err_scenario *err_scen = &err_scen_arr[usecase];
	u32 err_code_index;

	if (!err_scen->num_err_codes)
		return false;

	err_code_index = prandom_u32() % err_scen->num_err_codes;

	*index = err_code_index;
	*ret = err_scen->err_code_arr[err_code_index];
	return true;
}

void ufsdbg_error_inject_dispatcher(struct ufs_hba *hba,
			enum ufsdbg_err_inject_scenario usecase,
			int success_value, int *ret_value)
{
	int opt_ret = 0;
	u32 err_code_index = 0;

	/* sanity check and verify error scenario bit */
	if ((unlikely(!hba || !ret_value)) ||
	    (likely(!(hba->debugfs_files.err_inj_scenario_mask &
						BIT(usecase)))))
		goto out;

	if (usecase < 0 || usecase >= ERR_INJECT_MAX_ERR_SCENARIOS) {
		dev_err(hba->dev, "%s: invalid usecase value (%d)\n",
			__func__, usecase);
		goto out;
	}

	if (!ufsdbg_find_err_code(usecase, &opt_ret, &err_code_index))
		goto out;

	if (!should_fail(&hba->debugfs_files.fail_attr, 1))
		goto out;

	/* if an error already occurred/injected */
	if (*ret_value != success_value)
		goto out;

	switch (usecase) {
	case ERR_INJECT_INTR:
		/* an error already occurred */
		if (*ret_value & UFSHCD_ERROR_MASK)
			goto out;

		ufsdbg_intr_fail_request(hba, (u32 *)&opt_ret);
		/* fall through */
	case ERR_INJECT_PWR_CHANGE:
	case ERR_INJECT_UIC:
	case ERR_INJECT_DME_ATTR:
	case ERR_INJECT_QUERY:
		goto should_fail;
	default:
		dev_err(hba->dev, "%s: unsupported error scenario\n",
				__func__);
		goto out;
	}

should_fail:
	*ret_value = opt_ret;
	err_scen_arr[usecase].num_err_injected++;
	pr_debug("%s: error code index [%d], error code %d (0x%x) is injected for scenario \"%s\"\n",
		 __func__, err_code_index, *ret_value, *ret_value,
		 err_scen_arr[usecase].name);
out:
	/**
	 * here it's guaranteed that ret_value has the correct value,
	 * whether it was assigned with a new value, or kept its own
	 * original incoming value
	 */
	return;
}

static int ufsdbg_err_inj_scenario_read(struct seq_file *file, void *data)
{
	struct ufs_hba *hba = (struct ufs_hba *)file->private;
	enum ufsdbg_err_inject_scenario err_case;

	if (!hba)
		return -EINVAL;

	seq_printf(file, "%-40s %-17s %-15s\n",
		   "Error Scenario:", "Bit[#]", "STATUS");

	for (err_case = ERR_INJECT_INTR;
		err_case < ERR_INJECT_MAX_ERR_SCENARIOS; err_case++) {
		seq_printf(file, "%-40s 0x%-15lx %-15s\n",
			   err_scen_arr[err_case].name,
			   UFS_BIT(err_case),
			   hba->debugfs_files.err_inj_scenario_mask &
				UFS_BIT(err_case) ? "ENABLE" : "DISABLE");
	}

	seq_printf(file, "bitwise of error scenario is 0x%x\n\n",
		   hba->debugfs_files.err_inj_scenario_mask);

	seq_puts(file, "usage example:\n");
	seq_puts(file, "echo 0x4 > /sys/kernel/debug/.../err_inj_scenario\n");
	seq_puts(file, "in order to enable ERR_INJECT_INTR\n");

	return 0;
}

static
int ufsdbg_err_inj_scenario_open(struct inode *inode, struct file *file)
{
	return single_open(file,
			ufsdbg_err_inj_scenario_read, inode->i_private);
}

static ssize_t ufsdbg_err_inj_scenario_write(struct file *file,
				     const char __user *ubuf, size_t cnt,
				     loff_t *ppos)
{
	struct ufs_hba *hba = file->f_mapping->host->i_private;
	int ret;
	int err_scen = 0;

	if (!hba)
		return -EINVAL;

	ret = kstrtoint_from_user(ubuf, cnt, 0, &err_scen);
	if (ret) {
		dev_err(hba->dev, "%s: Invalid argument\n", __func__);
		return ret;
	}

	hba->debugfs_files.err_inj_scenario_mask = err_scen;

	return cnt;
}

static const struct file_operations ufsdbg_err_inj_scenario_ops = {
	.open		= ufsdbg_err_inj_scenario_open,
	.read		= seq_read,
	.write		= ufsdbg_err_inj_scenario_write,
};

static int ufsdbg_err_inj_stats_read(struct seq_file *file, void *data)
{
	enum ufsdbg_err_inject_scenario err;

	seq_printf(file, "%-40s %-20s\n",
		   "Error Scenario:", "Num of Errors Injected");

	for (err = 0; err < ERR_INJECT_MAX_ERR_SCENARIOS; err++) {
		seq_printf(file, "%-40s %-20d\n",
			err_scen_arr[err].name,
			err_scen_arr[err].num_err_injected);
	}

	return 0;
}

static
int ufsdbg_err_inj_stats_open(struct inode *inode, struct file *file)
{
	return single_open(file,
			ufsdbg_err_inj_stats_read, inode->i_private);
}

static ssize_t ufsdbg_err_inj_stats_write(struct file *file,
				     const char __user *ubuf, size_t cnt,
				     loff_t *ppos)
{
	enum ufsdbg_err_inject_scenario err;

	for (err = 0; err < ERR_INJECT_MAX_ERR_SCENARIOS; err++)
		err_scen_arr[err].num_err_injected = 0;

	return cnt;
}

static const struct file_operations ufsdbg_err_inj_stats_ops = {
	.open		= ufsdbg_err_inj_stats_open,
	.read		= seq_read,
	.write		= ufsdbg_err_inj_stats_write,
};

static void ufsdbg_setup_fault_injection(struct ufs_hba *hba)
{
	struct dentry *fault_dir;

	hba->debugfs_files.fail_attr = fail_default_attr;

	if (fail_request)
		setup_fault_attr(&hba->debugfs_files.fail_attr, fail_request);

	/* suppress dump stack every time failure is injected */
	hba->debugfs_files.fail_attr.verbose = 0;

	fault_dir = fault_create_debugfs_attr("inject_fault",
					hba->debugfs_files.debugfs_root,
					&hba->debugfs_files.fail_attr);

	if (IS_ERR(fault_dir)) {
		dev_err(hba->dev, "%s: failed to create debugfs entry for fault injection\n",
			__func__);
		return;
	}

	hba->debugfs_files.err_inj_scenario =
		debugfs_create_file("err_inj_scenario",
				   S_IRUGO | S_IWUGO,
				   hba->debugfs_files.debugfs_root, hba,
				   &ufsdbg_err_inj_scenario_ops);

	if (!hba->debugfs_files.err_inj_scenario) {
		dev_err(hba->dev,
			"%s: Could not create debugfs entry for err_scenario",
				__func__);
		goto fail_err_inj_scenario;
	}

	hba->debugfs_files.err_inj_stats =
		debugfs_create_file("err_inj_stats", S_IRUSR | S_IWUSR,
				    hba->debugfs_files.debugfs_root, hba,
				    &ufsdbg_err_inj_stats_ops);
	if (!hba->debugfs_files.err_inj_stats) {
		dev_err(hba->dev,
			"%s:  failed create err_inj_stats debugfs entry\n",
			__func__);
		goto fail_err_inj_stats;
	}

	return;

fail_err_inj_stats:
	debugfs_remove(hba->debugfs_files.err_inj_scenario);
fail_err_inj_scenario:
	debugfs_remove_recursive(fault_dir);
}
#else
static void ufsdbg_setup_fault_injection(struct ufs_hba *hba)
{
}
#endif /* CONFIG_UFS_FAULT_INJECTION */

#define BUFF_LINE_SIZE 16 /* Must be a multiplication of sizeof(u32) */
#define TAB_CHARS 8

static int ufsdbg_tag_stats_show(struct seq_file *file, void *data)
{
	struct ufs_hba *hba = (struct ufs_hba *)file->private;
	struct ufs_stats *ufs_stats;
	int i, j;
	int max_depth;
	bool is_tag_empty = true;
	unsigned long flags;
	char *sep = " | * | ";

	if (!hba)
		goto exit;

	ufs_stats = &hba->ufs_stats;

	if (!ufs_stats->enabled) {
		pr_debug("%s: ufs statistics are disabled\n", __func__);
		seq_puts(file, "ufs statistics are disabled");
		goto exit;
	}

	max_depth = hba->nutrs;

	spin_lock_irqsave(hba->host->host_lock, flags);
	/* Header */
	seq_printf(file, " Tag Stat\t\t%s Number of pending reqs upon issue (Q fullness)\n",
		sep);
	for (i = 0; i < TAB_CHARS * (TS_NUM_STATS + 4); i++) {
		seq_puts(file, "-");
		if (i == (TAB_CHARS * 3 - 1))
			seq_puts(file, sep);
	}
	seq_printf(file,
		"\n #\tnum uses\t%s\t #\tAll\tRead\tWrite\tUrg.R\tUrg.W\tFlush\n",
		sep);

	/* values */
	for (i = 0; i < max_depth; i++) {
		if (ufs_stats->tag_stats[i][TS_TAG] <= 0 &&
				ufs_stats->tag_stats[i][TS_READ] <= 0 &&
				ufs_stats->tag_stats[i][TS_WRITE] <= 0 &&
				ufs_stats->tag_stats[i][TS_URGENT_READ] <= 0 &&
				ufs_stats->tag_stats[i][TS_URGENT_WRITE] <= 0 &&
				ufs_stats->tag_stats[i][TS_FLUSH] <= 0)
			continue;

		is_tag_empty = false;
		seq_printf(file, " %d\t ", i);
		for (j = 0; j < TS_NUM_STATS; j++) {
			seq_printf(file, "%llu\t", ufs_stats->tag_stats[i][j]);
			if (j != 0)
				continue;
			seq_printf(file, "\t%s\t %d\t%llu\t", sep, i,
				ufs_stats->tag_stats[i][TS_READ] +
				ufs_stats->tag_stats[i][TS_WRITE] +
				ufs_stats->tag_stats[i][TS_URGENT_READ] +
				ufs_stats->tag_stats[i][TS_URGENT_WRITE] +
				ufs_stats->tag_stats[i][TS_FLUSH]);
		}
		seq_puts(file, "\n");
	}
	spin_unlock_irqrestore(hba->host->host_lock, flags);

	if (is_tag_empty)
		pr_debug("%s: All tags statistics are empty", __func__);

exit:
	return 0;
}

static int ufsdbg_tag_stats_open(struct inode *inode, struct file *file)
{
	return single_open(file, ufsdbg_tag_stats_show, inode->i_private);
}

static ssize_t ufsdbg_tag_stats_write(struct file *filp,
				      const char __user *ubuf, size_t cnt,
				       loff_t *ppos)
{
	struct ufs_hba *hba = filp->f_mapping->host->i_private;
	struct ufs_stats *ufs_stats;
	int val = 0;
	int ret, bit = 0;
	unsigned long flags;

	ret = kstrtoint_from_user(ubuf, cnt, 0, &val);
	if (ret) {
		dev_err(hba->dev, "%s: Invalid argument\n", __func__);
		return ret;
	}

	ufs_stats = &hba->ufs_stats;
	spin_lock_irqsave(hba->host->host_lock, flags);

	if (!val) {
		ufs_stats->enabled = false;
		pr_debug("%s: Disabling UFS tag statistics", __func__);
	} else {
		ufs_stats->enabled = true;
		pr_debug("%s: Enabling & Resetting UFS tag statistics",
			 __func__);
		memset(hba->ufs_stats.tag_stats[0], 0,
			sizeof(**hba->ufs_stats.tag_stats) *
			TS_NUM_STATS * hba->nutrs);

		/* initialize current queue depth */
		ufs_stats->q_depth = 0;
		for_each_set_bit_from(bit, &hba->outstanding_reqs, hba->nutrs)
			ufs_stats->q_depth++;
		pr_debug("%s: Enabled UFS tag statistics", __func__);
	}

	spin_unlock_irqrestore(hba->host->host_lock, flags);
	return cnt;
}

static const struct file_operations ufsdbg_tag_stats_fops = {
	.open		= ufsdbg_tag_stats_open,
	.read		= seq_read,
	.write		= ufsdbg_tag_stats_write,
};

static int ufsdbg_query_stats_show(struct seq_file *file, void *data)
{
	struct ufs_hba *hba = (struct ufs_hba *)file->private;
	struct ufs_stats *ufs_stats = &hba->ufs_stats;
	int i, j;
	static const char *opcode_name[UPIU_QUERY_OPCODE_MAX] = {
		"QUERY_OPCODE_NOP:",
		"QUERY_OPCODE_READ_DESC:",
		"QUERY_OPCODE_WRITE_DESC:",
		"QUERY_OPCODE_READ_ATTR:",
		"QUERY_OPCODE_WRITE_ATTR:",
		"QUERY_OPCODE_READ_FLAG:",
		"QUERY_OPCODE_SET_FLAG:",
		"QUERY_OPCODE_CLEAR_FLAG:",
		"QUERY_OPCODE_TOGGLE_FLAG:",
	};

	seq_puts(file, "\n");
	seq_puts(file, "The following table shows how many TIMES each IDN was sent to device for each QUERY OPCODE:\n");
	seq_puts(file, "\n");

	for (i = 0; i < UPIU_QUERY_OPCODE_MAX; i++) {
		seq_printf(file, "%-30s", opcode_name[i]);

		for (j = 0; j < MAX_QUERY_IDN; j++) {
			/*
			 * we would like to print only the non-zero data,
			 * (non-zero number of times that IDN was sent
			 * to the device per opcode). There is no
			 * importance to the "table structure" of the output.
			 */
			if (ufs_stats->query_stats_arr[i][j])
				seq_printf(file, "IDN 0x%02X: %d,\t", j,
					   ufs_stats->query_stats_arr[i][j]);
		}
		seq_puts(file, "\n");
	}

	return 0;
}

static int ufsdbg_query_stats_open(struct inode *inode, struct file *file)
{
	return single_open(file, ufsdbg_query_stats_show, inode->i_private);
}

static ssize_t ufsdbg_query_stats_write(struct file *filp,
				      const char __user *ubuf, size_t cnt,
				       loff_t *ppos)
{
	struct ufs_hba *hba = filp->f_mapping->host->i_private;
	struct ufs_stats *ufs_stats = &hba->ufs_stats;
	int i, j;

	mutex_lock(&hba->dev_cmd.lock);

	for (i = 0; i < UPIU_QUERY_OPCODE_MAX; i++)
		for (j = 0; j < MAX_QUERY_IDN; j++)
			ufs_stats->query_stats_arr[i][j] = 0;

	mutex_unlock(&hba->dev_cmd.lock);

	return cnt;
}

static const struct file_operations ufsdbg_query_stats_fops = {
	.open		= ufsdbg_query_stats_open,
	.read		= seq_read,
	.write		= ufsdbg_query_stats_write,
};

static int ufsdbg_err_stats_show(struct seq_file *file, void *data)
{
	struct ufs_hba *hba = (struct ufs_hba *)file->private;
	int *err_stats;
	unsigned long flags;
	bool error_seen = false;

	if (!hba)
		goto exit;

	err_stats = hba->ufs_stats.err_stats;

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

	seq_puts(file, "\n==UFS errors that caused controller reset==\n");

	UFS_ERR_STATS_PRINT(file, UFS_ERR_HIBERN8_EXIT,
			"controller reset due to hibern8 exit error:\t %d\n",
			error_seen);

	UFS_ERR_STATS_PRINT(file, UFS_ERR_VOPS_SUSPEND,
			"controller reset due to vops suspend error:\t\t %d\n",
			error_seen);

	UFS_ERR_STATS_PRINT(file, UFS_ERR_EH,
			"controller reset due to error handling:\t\t %d\n",
			error_seen);

	UFS_ERR_STATS_PRINT(file, UFS_ERR_CLEAR_PEND_XFER_TM,
			"controller reset due to clear xfer/tm regs:\t\t %d\n",
			error_seen);

	UFS_ERR_STATS_PRINT(file, UFS_ERR_INT_FATAL_ERRORS,
			"controller reset due to fatal interrupt:\t %d\n",
			error_seen);

	UFS_ERR_STATS_PRINT(file, UFS_ERR_INT_UIC_ERROR,
			"controller reset due to uic interrupt error:\t %d\n",
			error_seen);

	if (error_seen)
		error_seen = false;
	else
		seq_puts(file,
			"so far, no errors that caused controller reset\n\n");

	seq_puts(file, "\n\n==UFS other errors==\n");

	UFS_ERR_STATS_PRINT(file, UFS_ERR_HIBERN8_ENTER,
			"hibern8 enter:\t\t %d\n", error_seen);

	UFS_ERR_STATS_PRINT(file, UFS_ERR_RESUME,
			"resume error:\t\t %d\n", error_seen);

	UFS_ERR_STATS_PRINT(file, UFS_ERR_SUSPEND,
			"suspend error:\t\t %d\n", error_seen);

	UFS_ERR_STATS_PRINT(file, UFS_ERR_LINKSTARTUP,
			"linkstartup error:\t\t %d\n", error_seen);

	UFS_ERR_STATS_PRINT(file, UFS_ERR_POWER_MODE_CHANGE,
			"power change error:\t %d\n", error_seen);

	UFS_ERR_STATS_PRINT(file, UFS_ERR_TASK_ABORT,
			"abort callback:\t\t %d\n\n", error_seen);

	if (!error_seen)
		seq_puts(file,
		"so far, no other UFS related errors\n\n");

	spin_unlock_irqrestore(hba->host->host_lock, flags);
exit:
	return 0;
}

static int ufsdbg_err_stats_open(struct inode *inode, struct file *file)
{
	return single_open(file, ufsdbg_err_stats_show, inode->i_private);
}

static ssize_t ufsdbg_err_stats_write(struct file *filp,
				      const char __user *ubuf, size_t cnt,
				       loff_t *ppos)
{
	struct ufs_hba *hba = filp->f_mapping->host->i_private;
	struct ufs_stats *ufs_stats;
	unsigned long flags;

	ufs_stats = &hba->ufs_stats;
	spin_lock_irqsave(hba->host->host_lock, flags);

	pr_debug("%s: Resetting UFS error statistics", __func__);
	memset(ufs_stats->err_stats, 0, sizeof(hba->ufs_stats.err_stats));

	spin_unlock_irqrestore(hba->host->host_lock, flags);
	return cnt;
}

static const struct file_operations ufsdbg_err_stats_fops = {
	.open		= ufsdbg_err_stats_open,
	.read		= seq_read,
	.write		= ufsdbg_err_stats_write,
};

static int ufshcd_init_statistics(struct ufs_hba *hba)
{
	struct ufs_stats *stats = &hba->ufs_stats;
	int ret = 0;
	int i;

	stats->enabled = false;
	stats->tag_stats = kzalloc(sizeof(*stats->tag_stats) * hba->nutrs,
			GFP_KERNEL);
	if (!hba->ufs_stats.tag_stats)
		goto no_mem;

	stats->tag_stats[0] = kzalloc(sizeof(**stats->tag_stats) *
			TS_NUM_STATS * hba->nutrs, GFP_KERNEL);
	if (!stats->tag_stats[0])
		goto no_mem;

	for (i = 1; i < hba->nutrs; i++)
		stats->tag_stats[i] = &stats->tag_stats[0][i * TS_NUM_STATS];

	memset(stats->err_stats, 0, sizeof(hba->ufs_stats.err_stats));

	goto exit;

no_mem:
	dev_err(hba->dev, "%s: Unable to allocate UFS tag_stats", __func__);
	ret = -ENOMEM;
exit:
	return ret;
}

void ufsdbg_pr_buf_to_std(struct ufs_hba *hba, int offset, int num_regs,
				char *str, void *priv)
{
	int i;
	char linebuf[38];
	int size = num_regs * sizeof(u32);
	int lines = size / BUFF_LINE_SIZE +
			(size % BUFF_LINE_SIZE ? 1 : 0);
	struct seq_file *file = priv;

	if (!hba || !file) {
		pr_err("%s called with NULL pointer\n", __func__);
		return;
	}

	for (i = 0; i < lines; i++) {
		hex_dump_to_buffer(hba->mmio_base + offset + i * BUFF_LINE_SIZE,
				min(BUFF_LINE_SIZE, size), BUFF_LINE_SIZE, 4,
				linebuf, sizeof(linebuf), false);
		seq_printf(file, "%s [%x]: %s\n", str, i * BUFF_LINE_SIZE,
				linebuf);
		size -= BUFF_LINE_SIZE/sizeof(u32);
	}
}

static int ufsdbg_host_regs_show(struct seq_file *file, void *data)
{
	struct ufs_hba *hba = (struct ufs_hba *)file->private;

	pm_runtime_get_sync(hba->dev);
	ufshcd_hold(hba, false);
	ufsdbg_pr_buf_to_std(hba, 0, UFSHCI_REG_SPACE_SIZE / sizeof(u32),
				"host regs", file);
	ufshcd_release(hba, false);
	pm_runtime_put_sync(hba->dev);
	return 0;
}

static int ufsdbg_host_regs_open(struct inode *inode, struct file *file)
{
	return single_open(file, ufsdbg_host_regs_show, inode->i_private);
}

static const struct file_operations ufsdbg_host_regs_fops = {
	.open		= ufsdbg_host_regs_open,
	.read		= seq_read,
};

static int ufsdbg_dump_device_desc_show(struct seq_file *file, void *data)
{
	int err = 0;
	int buff_len = QUERY_DESC_DEVICE_MAX_SIZE;
	u8 desc_buf[QUERY_DESC_DEVICE_MAX_SIZE];
	struct ufs_hba *hba = (struct ufs_hba *)file->private;

	struct desc_field_offset device_desc_field_name[] = {
		{"bLength",		0x00, BYTE},
		{"bDescriptorType",	0x01, BYTE},
		{"bDevice",		0x02, BYTE},
		{"bDeviceClass",	0x03, BYTE},
		{"bDeviceSubClass",	0x04, BYTE},
		{"bProtocol",		0x05, BYTE},
		{"bNumberLU",		0x06, BYTE},
		{"bNumberWLU",		0x07, BYTE},
		{"bBootEnable",		0x08, BYTE},
		{"bDescrAccessEn",	0x09, BYTE},
		{"bInitPowerMode",	0x0A, BYTE},
		{"bHighPriorityLUN",	0x0B, BYTE},
		{"bSecureRemovalType",	0x0C, BYTE},
		{"bSecurityLU",		0x0D, BYTE},
		{"Reserved",		0x0E, BYTE},
		{"bInitActiveICCLevel",	0x0F, BYTE},
		{"wSpecVersion",	0x10, WORD},
		{"wManufactureDate",	0x12, WORD},
		{"iManufactureName",	0x14, BYTE},
		{"iProductName",	0x15, BYTE},
		{"iSerialNumber",	0x16, BYTE},
		{"iOemID",		0x17, BYTE},
		{"wManufactureID",	0x18, WORD},
		{"bUD0BaseOffset",	0x1A, BYTE},
		{"bUDConfigPLength",	0x1B, BYTE},
		{"bDeviceRTTCap",	0x1C, BYTE},
		{"wPeriodicRTCUpdate",	0x1D, WORD}
	};

	pm_runtime_get_sync(hba->dev);
	err = ufshcd_read_device_desc(hba, desc_buf, buff_len);
	pm_runtime_put_sync(hba->dev);

	if (!err) {
		int i;
		struct desc_field_offset *tmp;
		for (i = 0; i < ARRAY_SIZE(device_desc_field_name); ++i) {
			tmp = &device_desc_field_name[i];

			if (tmp->width_byte == BYTE) {
				seq_printf(file,
					   "Device Descriptor[Byte offset 0x%x]: %s = 0x%x\n",
					   tmp->offset,
					   tmp->name,
					   (u8)desc_buf[tmp->offset]);
			} else if (tmp->width_byte == WORD) {
				seq_printf(file,
					   "Device Descriptor[Byte offset 0x%x]: %s = 0x%x\n",
					   tmp->offset,
					   tmp->name,
					   *(u16 *)&desc_buf[tmp->offset]);
			} else {
				seq_printf(file,
				"Device Descriptor[offset 0x%x]: %s. Wrong Width = %d",
				tmp->offset, tmp->name, tmp->width_byte);
			}
		}
	} else {
		seq_printf(file, "Reading Device Descriptor failed. err = %d\n",
			   err);
	}

	return err;
}

static int ufsdbg_show_hba_show(struct seq_file *file, void *data)
{
	struct ufs_hba *hba = (struct ufs_hba *)file->private;

	seq_printf(file, "hba->outstanding_tasks = 0x%x\n",
			(u32)hba->outstanding_tasks);
	seq_printf(file, "hba->outstanding_reqs = 0x%x\n",
			(u32)hba->outstanding_reqs);

	seq_printf(file, "hba->capabilities = 0x%x\n", hba->capabilities);
	seq_printf(file, "hba->nutrs = %d\n", hba->nutrs);
	seq_printf(file, "hba->nutmrs = %d\n", hba->nutmrs);
	seq_printf(file, "hba->ufs_version = 0x%x\n", hba->ufs_version);
	seq_printf(file, "hba->irq = 0x%x\n", hba->irq);
	seq_printf(file, "hba->auto_bkops_enabled = %d\n",
			hba->auto_bkops_enabled);

	seq_printf(file, "hba->ufshcd_state = 0x%x\n", hba->ufshcd_state);
	seq_printf(file, "hba->clk_gating.state = 0x%x\n",
			hba->clk_gating.state);
	seq_printf(file, "hba->eh_flags = 0x%x\n", hba->eh_flags);
	seq_printf(file, "hba->intr_mask = 0x%x\n", hba->intr_mask);
	seq_printf(file, "hba->ee_ctrl_mask = 0x%x\n", hba->ee_ctrl_mask);

	/* HBA Errors */
	seq_printf(file, "hba->errors = 0x%x\n", hba->errors);
	seq_printf(file, "hba->uic_error = 0x%x\n", hba->uic_error);
	seq_printf(file, "hba->saved_err = 0x%x\n", hba->saved_err);
	seq_printf(file, "hba->saved_uic_err = 0x%x\n", hba->saved_uic_err);

	seq_printf(file, "power_mode_change_cnt = %d\n",
			hba->ufs_stats.power_mode_change_cnt);
	seq_printf(file, "hibern8_exit_cnt = %d\n",
			hba->ufs_stats.hibern8_exit_cnt);
	return 0;
}

static int ufsdbg_show_hba_open(struct inode *inode, struct file *file)
{
	return single_open(file, ufsdbg_show_hba_show, inode->i_private);
}

static const struct file_operations ufsdbg_show_hba_fops = {
	.open		= ufsdbg_show_hba_open,
	.read		= seq_read,
};

static int ufsdbg_dump_device_desc_open(struct inode *inode, struct file *file)
{
	return single_open(file,
			   ufsdbg_dump_device_desc_show, inode->i_private);
}

static const struct file_operations ufsdbg_dump_device_desc = {
	.open		= ufsdbg_dump_device_desc_open,
	.read		= seq_read,
};

static int ufsdbg_power_mode_show(struct seq_file *file, void *data)
{
	struct ufs_hba *hba = (struct ufs_hba *)file->private;
	char *names[] = {
		"INVALID MODE",
		"FAST MODE",
		"SLOW MODE",
		"INVALID MODE",
		"FASTAUTO MODE",
		"SLOWAUTO MODE",
		"INVALID MODE",
	};

	/* Print current status */
	seq_puts(file, "UFS current power mode [RX, TX]:");
	seq_printf(file, "gear=[%d,%d], lane=[%d,%d], pwr=[%s,%s], rate = %c",
		 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 == PA_HS_MODE_B ? 'B' : 'A');
	seq_puts(file, "\n\n");

	/* Print usage */
	seq_puts(file,
		"To change power mode write 'GGLLMM' where:\n"
		"G - selected gear\n"
		"L - number of lanes\n"
		"M - power mode:\n"
		"\t1 = fast mode\n"
		"\t2 = slow mode\n"
		"\t4 = fast-auto mode\n"
		"\t5 = slow-auto mode\n"
		"first letter is for RX, second letter is for TX.\n\n");

	return 0;
}

static bool ufsdbg_power_mode_validate(struct ufs_pa_layer_attr *pwr_mode)
{
	if (pwr_mode->gear_rx < UFS_PWM_G1 || pwr_mode->gear_rx > UFS_PWM_G7 ||
	    pwr_mode->gear_tx < UFS_PWM_G1 || pwr_mode->gear_tx > UFS_PWM_G7 ||
	    pwr_mode->lane_rx < 1 || pwr_mode->lane_rx > 2 ||
	    pwr_mode->lane_tx < 1 || pwr_mode->lane_tx > 2 ||
	    (pwr_mode->pwr_rx != FAST_MODE && pwr_mode->pwr_rx != SLOW_MODE &&
	     pwr_mode->pwr_rx != FASTAUTO_MODE &&
	     pwr_mode->pwr_rx != SLOWAUTO_MODE) ||
	    (pwr_mode->pwr_tx != FAST_MODE && pwr_mode->pwr_tx != SLOW_MODE &&
	     pwr_mode->pwr_tx != FASTAUTO_MODE &&
	     pwr_mode->pwr_tx != SLOWAUTO_MODE)) {
		pr_err("%s: power parameters are not valid\n", __func__);
		return false;
	}

	return true;
}

static int ufsdbg_cfg_pwr_param(struct ufs_hba *hba,
				struct ufs_pa_layer_attr *new_pwr,
				struct ufs_pa_layer_attr *final_pwr)
{
	int ret = 0;
	bool is_dev_sup_hs = false;
	bool is_new_pwr_hs = false;
	int dev_pwm_max_rx_gear;
	int dev_pwm_max_tx_gear;

	if (!hba->max_pwr_info.is_valid) {
		dev_err(hba->dev, "%s: device max power is not valid. can't configure power\n",
			__func__);
		return -EINVAL;
	}

	if (hba->max_pwr_info.info.pwr_rx == FAST_MODE)
		is_dev_sup_hs = true;

	if (new_pwr->pwr_rx == FAST_MODE || new_pwr->pwr_rx == FASTAUTO_MODE)
		is_new_pwr_hs = true;

	final_pwr->lane_rx = hba->max_pwr_info.info.lane_rx;
	final_pwr->lane_tx = hba->max_pwr_info.info.lane_tx;

	/* device doesn't support HS but requested power is HS */
	if (!is_dev_sup_hs && is_new_pwr_hs) {
		pr_err("%s: device doesn't support HS. requested power is HS\n",
			__func__);
		return -ENOTSUPP;
	} else if ((is_dev_sup_hs && is_new_pwr_hs) ||
		   (!is_dev_sup_hs && !is_new_pwr_hs)) {
		/*
		 * If device and requested power mode are both HS or both PWM
		 * then dev_max->gear_xx are the gears to be assign to
		 * final_pwr->gear_xx
		 */
		final_pwr->gear_rx = hba->max_pwr_info.info.gear_rx;
		final_pwr->gear_tx = hba->max_pwr_info.info.gear_tx;
	} else if (is_dev_sup_hs && !is_new_pwr_hs) {
		/*
		 * If device supports HS but requested power is PWM, then we
		 * need to find out what is the max gear in PWM the device
		 * supports
		 */

		ufshcd_dme_get(hba, UIC_ARG_MIB(PA_MAXRXPWMGEAR),
			       &dev_pwm_max_rx_gear);

		if (!dev_pwm_max_rx_gear) {
			pr_err("%s: couldn't get device max pwm rx gear\n",
				__func__);
			ret = -EINVAL;
			goto out;
		}

		ufshcd_dme_peer_get(hba, UIC_ARG_MIB(PA_MAXRXPWMGEAR),
				    &dev_pwm_max_tx_gear);

		if (!dev_pwm_max_tx_gear) {
			pr_err("%s: couldn't get device max pwm tx gear\n",
				__func__);
			ret = -EINVAL;
			goto out;
		}

		final_pwr->gear_rx = dev_pwm_max_rx_gear;
		final_pwr->gear_tx = dev_pwm_max_tx_gear;
	}

	if ((new_pwr->gear_rx > final_pwr->gear_rx) ||
	    (new_pwr->gear_tx > final_pwr->gear_tx) ||
	    (new_pwr->lane_rx > final_pwr->lane_rx) ||
	    (new_pwr->lane_tx > final_pwr->lane_tx)) {
		pr_err("%s: (RX,TX) GG,LL: in PWM/HS new pwr [%d%d,%d%d] exceeds device limitation [%d%d,%d%d]\n",
			__func__,
			new_pwr->gear_rx, new_pwr->gear_tx,
			new_pwr->lane_rx, new_pwr->lane_tx,
			final_pwr->gear_rx, final_pwr->gear_tx,
			final_pwr->lane_rx, final_pwr->lane_tx);
		return -ENOTSUPP;
	}

	final_pwr->gear_rx = new_pwr->gear_rx;
	final_pwr->gear_tx = new_pwr->gear_tx;
	final_pwr->lane_rx = new_pwr->lane_rx;
	final_pwr->lane_tx = new_pwr->lane_tx;
	final_pwr->pwr_rx = new_pwr->pwr_rx;
	final_pwr->pwr_tx = new_pwr->pwr_tx;
	final_pwr->hs_rate = new_pwr->hs_rate;

out:
	return ret;
}

static int ufsdbg_config_pwr_mode(struct ufs_hba *hba,
		struct ufs_pa_layer_attr *desired_pwr_mode)
{
	int ret;

	pm_runtime_get_sync(hba->dev);
	ufshcd_scsi_block_requests(hba);
	ret = ufshcd_wait_for_doorbell_clr(hba, DOORBELL_CLR_TOUT_US);
	if (!ret)
		ret = ufshcd_change_power_mode(hba, desired_pwr_mode);
	ufshcd_scsi_unblock_requests(hba);
	pm_runtime_put_sync(hba->dev);

	return ret;
}

static ssize_t ufsdbg_power_mode_write(struct file *file,
				const char __user *ubuf, size_t cnt,
				loff_t *ppos)
{
	struct ufs_hba *hba = file->f_mapping->host->i_private;
	struct ufs_pa_layer_attr pwr_mode;
	struct ufs_pa_layer_attr final_pwr_mode;
	char pwr_mode_str[BUFF_LINE_SIZE] = {0};
	loff_t buff_pos = 0;
	int ret;
	int idx = 0;

	ret = simple_write_to_buffer(pwr_mode_str, BUFF_LINE_SIZE,
		&buff_pos, ubuf, cnt);

	pwr_mode.gear_rx = pwr_mode_str[idx++] - '0';
	pwr_mode.gear_tx = pwr_mode_str[idx++] - '0';
	pwr_mode.lane_rx = pwr_mode_str[idx++] - '0';
	pwr_mode.lane_tx = pwr_mode_str[idx++] - '0';
	pwr_mode.pwr_rx = pwr_mode_str[idx++] - '0';
	pwr_mode.pwr_tx = pwr_mode_str[idx++] - '0';

	/*
	 * Switching between rates is not currently supported so use the
	 * current rate.
	 * TODO: add rate switching if and when it is supported in the future
	 */
	pwr_mode.hs_rate = hba->pwr_info.hs_rate;

	/* Validate user input */
	if (!ufsdbg_power_mode_validate(&pwr_mode))
		return -EINVAL;

	pr_debug("%s: new power mode requested [RX,TX]: Gear=[%d,%d], Lane=[%d,%d], Mode=[%d,%d]\n",
		__func__,
		pwr_mode.gear_rx, pwr_mode.gear_tx, pwr_mode.lane_rx,
		pwr_mode.lane_tx, pwr_mode.pwr_rx, pwr_mode.pwr_tx);

	ret = ufsdbg_cfg_pwr_param(hba, &pwr_mode, &final_pwr_mode);
	if (ret) {
		dev_err(hba->dev,
			"%s: failed to configure new power parameters, ret = %d\n",
			__func__, ret);
		return cnt;
	}

	ret = ufsdbg_config_pwr_mode(hba, &final_pwr_mode);
	if (ret == -EBUSY)
		dev_err(hba->dev,
			"%s: ufshcd_config_pwr_mode failed: system is busy, try again\n",
			__func__);
	else if (ret)
		dev_err(hba->dev,
			"%s: ufshcd_config_pwr_mode failed, ret=%d\n",
			__func__, ret);

	return cnt;
}

static int ufsdbg_power_mode_open(struct inode *inode, struct file *file)
{
	return single_open(file, ufsdbg_power_mode_show, inode->i_private);
}

static const struct file_operations ufsdbg_power_mode_desc = {
	.open		= ufsdbg_power_mode_open,
	.read		= seq_read,
	.write		= ufsdbg_power_mode_write,
};

static int ufsdbg_dme_read(void *data, u64 *attr_val, bool peer)
{
	int ret;
	struct ufs_hba *hba = data;
	u32 attr_id, read_val = 0;
	int (*read_func)(struct ufs_hba *, u32, u32 *);
	u32 attr_sel;

	if (!hba)
		return -EINVAL;

	read_func = peer ? ufshcd_dme_peer_get : ufshcd_dme_get;
	attr_id = peer ? hba->debugfs_files.dme_peer_attr_id :
			 hba->debugfs_files.dme_local_attr_id;
	pm_runtime_get_sync(hba->dev);
	ufshcd_scsi_block_requests(hba);
	ret = ufshcd_wait_for_doorbell_clr(hba, DOORBELL_CLR_TOUT_US);
	if (!ret) {
		if ((attr_id >= MPHY_RX_ATTR_ADDR_START)
		    && (attr_id <= MPHY_RX_ATTR_ADDR_END))
			attr_sel = UIC_ARG_MIB_SEL(attr_id,
					UIC_ARG_MPHY_RX_GEN_SEL_INDEX(0));
		else
			attr_sel = UIC_ARG_MIB(attr_id);

		ret = read_func(hba, attr_sel, &read_val);
	}
	ufshcd_scsi_unblock_requests(hba);
	pm_runtime_put_sync(hba->dev);

	if (!ret)
		*attr_val = (u64)read_val;

	return ret;
}

static int ufsdbg_dme_local_set_attr_id(void *data, u64 attr_id)
{
	struct ufs_hba *hba = data;

	if (!hba)
		return -EINVAL;

	hba->debugfs_files.dme_local_attr_id = (u32)attr_id;

	return 0;
}

static int ufsdbg_dme_local_read(void *data, u64 *attr_val)
{
	return ufsdbg_dme_read(data, attr_val, false);
}

DEFINE_SIMPLE_ATTRIBUTE(ufsdbg_dme_local_read_ops,
			ufsdbg_dme_local_read,
			ufsdbg_dme_local_set_attr_id,
			"%llu\n");

static int ufsdbg_dme_peer_read(void *data, u64 *attr_val)
{
	struct ufs_hba *hba = data;

	if (!hba)
		return -EINVAL;
	else
		return ufsdbg_dme_read(data, attr_val, true);
}

static int ufsdbg_dme_peer_set_attr_id(void *data, u64 attr_id)
{
	struct ufs_hba *hba = data;

	if (!hba)
		return -EINVAL;

	hba->debugfs_files.dme_peer_attr_id = (u32)attr_id;

	return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(ufsdbg_dme_peer_read_ops,
			ufsdbg_dme_peer_read,
			ufsdbg_dme_peer_set_attr_id,
			"%llu\n");

static int ufsdbg_dbg_print_en_read(void *data, u64 *attr_val)
{
	struct ufs_hba *hba = data;

	if (!hba)
		return -EINVAL;

	*attr_val = (u64)hba->ufshcd_dbg_print;
	return 0;
}

static int ufsdbg_dbg_print_en_set(void *data, u64 attr_id)
{
	struct ufs_hba *hba = data;

	if (!hba)
		return -EINVAL;

	if (attr_id & ~UFSHCD_DBG_PRINT_ALL)
		return -EINVAL;

	hba->ufshcd_dbg_print = (u32)attr_id;
	return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(ufsdbg_dbg_print_en_ops,
			ufsdbg_dbg_print_en_read,
			ufsdbg_dbg_print_en_set,
			"%llu\n");

static ssize_t ufsdbg_req_stats_write(struct file *filp,
		const char __user *ubuf, size_t cnt, loff_t *ppos)
{
	struct ufs_hba *hba = filp->f_mapping->host->i_private;
	int val;
	int ret;
	unsigned long flags;

	ret = kstrtoint_from_user(ubuf, cnt, 0, &val);
	if (ret) {
		dev_err(hba->dev, "%s: Invalid argument\n", __func__);
		return ret;
	}

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

	return cnt;
}

static int ufsdbg_req_stats_show(struct seq_file *file, void *data)
{
	struct ufs_hba *hba = (struct ufs_hba *)file->private;
	int i;
	unsigned long flags;

	/* Header */
	seq_printf(file, "\t%-10s %-10s %-10s %-10s %-10s %-10s",
		"All", "Write", "Read", "Read(urg)", "Write(urg)", "Flush");

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

	seq_printf(file, "\n%s:\t", "Min");
	for (i = 0; i < TS_NUM_STATS; i++)
		seq_printf(file, "%-10llu ", hba->ufs_stats.req_stats[i].min);
	seq_printf(file, "\n%s:\t", "Max");
	for (i = 0; i < TS_NUM_STATS; i++)
		seq_printf(file, "%-10llu ", hba->ufs_stats.req_stats[i].max);
	seq_printf(file, "\n%s:\t", "Avg.");
	for (i = 0; i < TS_NUM_STATS; i++)
		seq_printf(file, "%-10llu ",
			div64_u64(hba->ufs_stats.req_stats[i].sum,
				hba->ufs_stats.req_stats[i].count));
	seq_printf(file, "\n%s:\t", "Count");
	for (i = 0; i < TS_NUM_STATS; i++)
		seq_printf(file, "%-10llu ", hba->ufs_stats.req_stats[i].count);
	seq_puts(file, "\n");
	spin_unlock_irqrestore(hba->host->host_lock, flags);

	return 0;
}

static int ufsdbg_req_stats_open(struct inode *inode, struct file *file)
{
	return single_open(file, ufsdbg_req_stats_show, inode->i_private);
}

static const struct file_operations ufsdbg_req_stats_desc = {
	.open		= ufsdbg_req_stats_open,
	.read		= seq_read,
	.write		= ufsdbg_req_stats_write,
};


static int ufsdbg_reset_controller_show(struct seq_file *file, void *data)
{
	seq_puts(file, "echo 1 > /sys/kernel/debug/.../reset_controller\n");
	seq_puts(file, "resets the UFS controller and restores its operational state\n\n");

	return 0;
}

static int ufsdbg_reset_controller_open(struct inode *inode, struct file *file)
{
	return single_open(file, ufsdbg_reset_controller_show,
						inode->i_private);
}

static ssize_t ufsdbg_reset_controller_write(struct file *filp,
		const char __user *ubuf, size_t cnt, loff_t *ppos)
{
	struct ufs_hba *hba = filp->f_mapping->host->i_private;
	unsigned long flags;

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

	spin_lock_irqsave(hba->host->host_lock, flags);
	/*
	 * simulating a dummy error in order to "convince"
	 * eh_work to actually reset the controller
	 */
	hba->saved_err |= INT_FATAL_ERRORS;
	hba->silence_err_logs = true;
	schedule_work(&hba->eh_work);
	spin_unlock_irqrestore(hba->host->host_lock, flags);

	flush_work(&hba->eh_work);

	ufshcd_release(hba, false);
	pm_runtime_put_sync(hba->dev);

	return cnt;
}

static const struct file_operations ufsdbg_reset_controller = {
	.open		= ufsdbg_reset_controller_open,
	.read		= seq_read,
	.write		= ufsdbg_reset_controller_write,
};

static int ufsdbg_clear_err_state(void *data, u64 val)
{
	struct ufs_hba *hba = data;

	if (!hba)
		return -EINVAL;

	/* clear the error state on any write attempt */
	hba->debugfs_files.err_occurred = false;

	return 0;
}

static int ufsdbg_read_err_state(void *data, u64 *val)
{
	struct ufs_hba *hba = data;

	if (!hba)
		return -EINVAL;

	*val = hba->debugfs_files.err_occurred ? 1 : 0;

	return 0;
}

void ufsdbg_set_err_state(struct ufs_hba *hba)
{
	hba->debugfs_files.err_occurred = true;
}

DEFINE_SIMPLE_ATTRIBUTE(ufsdbg_err_state,
			ufsdbg_read_err_state,
			ufsdbg_clear_err_state,
			"%llu\n");

void ufsdbg_add_debugfs(struct ufs_hba *hba)
{
	char root_name[sizeof("ufshcd00")];

	if (!hba) {
		pr_err("%s: NULL hba, exiting", __func__);
		return;
	}

	snprintf(root_name, ARRAY_SIZE(root_name), "%s%d", UFSHCD,
		hba->host->host_no);

	hba->debugfs_files.debugfs_root = debugfs_create_dir(root_name, NULL);
	if (IS_ERR(hba->debugfs_files.debugfs_root))
		/* Don't complain -- debugfs just isn't enabled */
		goto err_no_root;
	if (!hba->debugfs_files.debugfs_root) {
		/*
		 * Complain -- debugfs is enabled, but it failed to
		 * create the directory
		 */
		dev_err(hba->dev,
			"%s: NULL debugfs root directory, exiting", __func__);
		goto err_no_root;
	}

	hba->debugfs_files.stats_folder = debugfs_create_dir("stats",
					hba->debugfs_files.debugfs_root);
	if (!hba->debugfs_files.stats_folder) {
		dev_err(hba->dev,
			"%s: NULL stats_folder, exiting", __func__);
		goto err;
	}

	hba->debugfs_files.tag_stats =
		debugfs_create_file("tag_stats", S_IRUSR | S_IWUSR,
					   hba->debugfs_files.stats_folder, hba,
					   &ufsdbg_tag_stats_fops);
	if (!hba->debugfs_files.tag_stats) {
		dev_err(hba->dev, "%s:  NULL tag_stats file, exiting",
			__func__);
		goto err;
	}

	hba->debugfs_files.query_stats =
		debugfs_create_file("query_stats", S_IRUSR | S_IWUSR,
					   hba->debugfs_files.stats_folder, hba,
					   &ufsdbg_query_stats_fops);
	if (!hba->debugfs_files.query_stats) {
		dev_err(hba->dev, "%s:  NULL query_stats file, exiting",
			__func__);
		goto err;
	}

	hba->debugfs_files.err_stats =
		debugfs_create_file("err_stats", S_IRUSR | S_IWUSR,
					   hba->debugfs_files.stats_folder, hba,
					   &ufsdbg_err_stats_fops);
	if (!hba->debugfs_files.err_stats) {
		dev_err(hba->dev, "%s:  NULL err_stats file, exiting",
			__func__);
		goto err;
	}

	if (ufshcd_init_statistics(hba)) {
		dev_err(hba->dev, "%s: Error initializing statistics",
			__func__);
		goto err;
	}

	hba->debugfs_files.host_regs = debugfs_create_file("host_regs", S_IRUSR,
				hba->debugfs_files.debugfs_root, hba,
				&ufsdbg_host_regs_fops);
	if (!hba->debugfs_files.host_regs) {
		dev_err(hba->dev, "%s:  NULL hcd regs file, exiting", __func__);
		goto err;
	}

	hba->debugfs_files.show_hba = debugfs_create_file("show_hba", S_IRUSR,
				hba->debugfs_files.debugfs_root, hba,
				&ufsdbg_show_hba_fops);
	if (!hba->debugfs_files.show_hba) {
		dev_err(hba->dev, "%s:  NULL hba file, exiting", __func__);
		goto err;
	}

	hba->debugfs_files.dump_dev_desc =
		debugfs_create_file("dump_device_desc", S_IRUSR,
				    hba->debugfs_files.debugfs_root, hba,
				    &ufsdbg_dump_device_desc);
	if (!hba->debugfs_files.dump_dev_desc) {
		dev_err(hba->dev,
			"%s:  NULL dump_device_desc file, exiting", __func__);
		goto err;
	}

	hba->debugfs_files.power_mode =
		debugfs_create_file("power_mode", S_IRUSR | S_IWUSR,
				    hba->debugfs_files.debugfs_root, hba,
				    &ufsdbg_power_mode_desc);
	if (!hba->debugfs_files.power_mode) {
		dev_err(hba->dev,
			"%s:  NULL power_mode_desc file, exiting", __func__);
		goto err;
	}

	hba->debugfs_files.dme_local_read =
		debugfs_create_file("dme_local_read", S_IRUSR | S_IWUSR,
				    hba->debugfs_files.debugfs_root, hba,
				    &ufsdbg_dme_local_read_ops);
	if (!hba->debugfs_files.dme_local_read) {
		dev_err(hba->dev,
			"%s:  failed create dme_local_read debugfs entry\n",
			__func__);
		goto err;
	}

	hba->debugfs_files.dme_peer_read =
		debugfs_create_file("dme_peer_read", S_IRUSR | S_IWUSR,
				    hba->debugfs_files.debugfs_root, hba,
				    &ufsdbg_dme_peer_read_ops);
	if (!hba->debugfs_files.dme_peer_read) {
		dev_err(hba->dev,
			"%s:  failed create dme_peer_read debugfs entry\n",
			__func__);
		goto err;
	}

	hba->debugfs_files.dbg_print_en =
		debugfs_create_file("dbg_print_en", S_IRUSR | S_IWUSR,
				    hba->debugfs_files.debugfs_root, hba,
				    &ufsdbg_dbg_print_en_ops);
	if (!hba->debugfs_files.dbg_print_en) {
		dev_err(hba->dev,
			"%s:  failed create dbg_print_en debugfs entry\n",
			__func__);
		goto err;
	}

	hba->debugfs_files.req_stats =
		debugfs_create_file("req_stats", S_IRUSR | S_IWUSR,
			hba->debugfs_files.stats_folder, hba,
			&ufsdbg_req_stats_desc);
	if (!hba->debugfs_files.req_stats) {
		dev_err(hba->dev,
			"%s:  failed create req_stats debugfs entry\n",
			__func__);
		goto err;
	}

	hba->debugfs_files.reset_controller =
		debugfs_create_file("reset_controller", S_IRUSR | S_IWUSR,
			hba->debugfs_files.debugfs_root, hba,
			&ufsdbg_reset_controller);
	if (!hba->debugfs_files.reset_controller) {
		dev_err(hba->dev,
			"%s: failed create reset_controller debugfs entry",
				__func__);
		goto err;
	}

	hba->debugfs_files.err_state =
		debugfs_create_file("err_state", S_IRUSR | S_IWUSR,
			hba->debugfs_files.debugfs_root, hba,
			&ufsdbg_err_state);
	if (!hba->debugfs_files.err_state) {
		dev_err(hba->dev,
		     "%s: failed create err_state debugfs entry", __func__);
		goto err;
	}

	ufsdbg_setup_fault_injection(hba);

	ufshcd_vops_add_debugfs(hba, hba->debugfs_files.debugfs_root);

	return;

err:
	debugfs_remove_recursive(hba->debugfs_files.debugfs_root);
	hba->debugfs_files.debugfs_root = NULL;
err_no_root:
	dev_err(hba->dev, "%s: failed to initialize debugfs\n", __func__);
}

void ufsdbg_remove_debugfs(struct ufs_hba *hba)
{
	ufshcd_vops_remove_debugfs(hba);
	debugfs_remove_recursive(hba->debugfs_files.debugfs_root);
	kfree(hba->ufs_stats.tag_stats);

}