/*
 * Copyright 2018 Advanced Micro Devices, Inc.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 *
 *
 */
#include <linux/debugfs.h>
#include <linux/list.h>
#include <linux/module.h>
#include "amdgpu.h"
#include "amdgpu_ras.h"
#include "amdgpu_atomfirmware.h"

struct ras_ih_data {
	/* interrupt bottom half */
	struct work_struct ih_work;
	int inuse;
	/* IP callback */
	ras_ih_cb cb;
	/* full of entries */
	unsigned char *ring;
	unsigned int ring_size;
	unsigned int element_size;
	unsigned int aligned_element_size;
	unsigned int rptr;
	unsigned int wptr;
};

struct ras_fs_data {
	char sysfs_name[32];
	char debugfs_name[32];
};

struct ras_err_data {
	unsigned long ue_count;
	unsigned long ce_count;
};

struct ras_err_handler_data {
	/* point to bad pages array */
	struct {
		unsigned long bp;
		struct amdgpu_bo *bo;
	} *bps;
	/* the count of entries */
	int count;
	/* the space can place new entries */
	int space_left;
	/* last reserved entry's index + 1 */
	int last_reserved;
};

struct ras_manager {
	struct ras_common_if head;
	/* reference count */
	int use;
	/* ras block link */
	struct list_head node;
	/* the device */
	struct amdgpu_device *adev;
	/* debugfs */
	struct dentry *ent;
	/* sysfs */
	struct device_attribute sysfs_attr;
	int attr_inuse;

	/* fs node name */
	struct ras_fs_data fs_data;

	/* IH data */
	struct ras_ih_data ih_data;

	struct ras_err_data err_data;
};

const char *ras_error_string[] = {
	"none",
	"parity",
	"single_correctable",
	"multi_uncorrectable",
	"poison",
};

const char *ras_block_string[] = {
	"umc",
	"sdma",
	"gfx",
	"mmhub",
	"athub",
	"pcie_bif",
	"hdp",
	"xgmi_wafl",
	"df",
	"smn",
	"sem",
	"mp0",
	"mp1",
	"fuse",
};

#define ras_err_str(i) (ras_error_string[ffs(i)])
#define ras_block_str(i) (ras_block_string[i])

#define AMDGPU_RAS_FLAG_INIT_BY_VBIOS 1
#define RAS_DEFAULT_FLAGS (AMDGPU_RAS_FLAG_INIT_BY_VBIOS)

static void amdgpu_ras_self_test(struct amdgpu_device *adev)
{
	/* TODO */
}

static ssize_t amdgpu_ras_debugfs_read(struct file *f, char __user *buf,
					size_t size, loff_t *pos)
{
	struct ras_manager *obj = (struct ras_manager *)file_inode(f)->i_private;
	struct ras_query_if info = {
		.head = obj->head,
	};
	ssize_t s;
	char val[128];

	if (amdgpu_ras_error_query(obj->adev, &info))
		return -EINVAL;

	s = snprintf(val, sizeof(val), "%s: %lu\n%s: %lu\n",
			"ue", info.ue_count,
			"ce", info.ce_count);
	if (*pos >= s)
		return 0;

	s -= *pos;
	s = min_t(u64, s, size);


	if (copy_to_user(buf, &val[*pos], s))
		return -EINVAL;

	*pos += s;

	return s;
}

static const struct file_operations amdgpu_ras_debugfs_ops = {
	.owner = THIS_MODULE,
	.read = amdgpu_ras_debugfs_read,
	.write = NULL,
	.llseek = default_llseek
};

static int amdgpu_ras_find_block_id_by_name(const char *name, int *block_id)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(ras_block_string); i++) {
		*block_id = i;
		if (strcmp(name, ras_block_str(i)) == 0)
			return 0;
	}
	return -EINVAL;
}

static int amdgpu_ras_debugfs_ctrl_parse_data(struct file *f,
		const char __user *buf, size_t size,
		loff_t *pos, struct ras_debug_if *data)
{
	ssize_t s = min_t(u64, 64, size);
	char str[65];
	char block_name[33];
	char err[9] = "ue";
	int op = -1;
	int block_id;
	u64 address, value;

	if (*pos)
		return -EINVAL;
	*pos = size;

	memset(str, 0, sizeof(str));
	memset(data, 0, sizeof(*data));

	if (copy_from_user(str, buf, s))
		return -EINVAL;

	if (sscanf(str, "disable %32s", block_name) == 1)
		op = 0;
	else if (sscanf(str, "enable %32s %8s", block_name, err) == 2)
		op = 1;
	else if (sscanf(str, "inject %32s %8s", block_name, err) == 2)
		op = 2;
	else if (str[0] && str[1] && str[2] && str[3])
		/* ascii string, but commands are not matched. */
		return -EINVAL;

	if (op != -1) {
		if (amdgpu_ras_find_block_id_by_name(block_name, &block_id))
			return -EINVAL;

		data->head.block = block_id;
		data->head.type = memcmp("ue", err, 2) == 0 ?
			AMDGPU_RAS_ERROR__MULTI_UNCORRECTABLE :
			AMDGPU_RAS_ERROR__SINGLE_CORRECTABLE;
		data->op = op;

		if (op == 2) {
			if (sscanf(str, "%*s %*s %*s %llu %llu",
						&address, &value) != 2)
				if (sscanf(str, "%*s %*s %*s 0x%llx 0x%llx",
							&address, &value) != 2)
					return -EINVAL;
			data->inject.address = address;
			data->inject.value = value;
		}
	} else {
		if (size < sizeof(*data))
			return -EINVAL;

		if (copy_from_user(data, buf, sizeof(*data)))
			return -EINVAL;
	}

	return 0;
}
/*
 * DOC: ras debugfs control interface
 *
 * It accepts struct ras_debug_if who has two members.
 *
 * First member: ras_debug_if::head or ras_debug_if::inject.
 *
 * head is used to indicate which IP block will be under control.
 *
 * head has four members, they are block, type, sub_block_index, name.
 * block: which IP will be under control.
 * type: what kind of error will be enabled/disabled/injected.
 * sub_block_index: some IPs have subcomponets. say, GFX, sDMA.
 * name: the name of IP.
 *
 * inject has two more members than head, they are address, value.
 * As their names indicate, inject operation will write the
 * value to the address.
 *
 * Second member: struct ras_debug_if::op.
 * It has three kinds of operations.
 *  0: disable RAS on the block. Take ::head as its data.
 *  1: enable RAS on the block. Take ::head as its data.
 *  2: inject errors on the block. Take ::inject as its data.
 *
 * How to use the interface?
 * programs:
 * copy the struct ras_debug_if in your codes and initialize it.
 * write the struct to the control node.
 *
 * bash:
 * echo op block [error [address value]] > .../ras/ras_ctrl
 *	op: disable, enable, inject
 *		disable: only block is needed
 *		enable: block and error are needed
 *		inject: error, address, value are needed
 *	block: umc, smda, gfx, .........
 *		see ras_block_string[] for details
 *	error: ue, ce
 *		ue: multi_uncorrectable
 *		ce: single_correctable
 *
 * here are some examples for bash commands,
 *	echo inject umc ue 0x0 0x0 > /sys/kernel/debug/dri/0/ras/ras_ctrl
 *	echo inject umc ce 0 0 > /sys/kernel/debug/dri/0/ras/ras_ctrl
 *	echo disable umc > /sys/kernel/debug/dri/0/ras/ras_ctrl
 *
 * How to check the result?
 *
 * For disable/enable, please check ras features at
 * /sys/class/drm/card[0/1/2...]/device/ras/features
 *
 * For inject, please check corresponding err count at
 * /sys/class/drm/card[0/1/2...]/device/ras/[gfx/sdma/...]_err_count
 *
 * NOTE: operation is only allowed on blocks which are supported.
 * Please check ras mask at /sys/module/amdgpu/parameters/ras_mask
 */
static ssize_t amdgpu_ras_debugfs_ctrl_write(struct file *f, const char __user *buf,
		size_t size, loff_t *pos)
{
	struct amdgpu_device *adev = (struct amdgpu_device *)file_inode(f)->i_private;
	struct ras_debug_if data;
	int ret = 0;

	ret = amdgpu_ras_debugfs_ctrl_parse_data(f, buf, size, pos, &data);
	if (ret)
		return -EINVAL;

	if (!amdgpu_ras_is_supported(adev, data.head.block))
		return -EINVAL;

	switch (data.op) {
	case 0:
		ret = amdgpu_ras_feature_enable(adev, &data.head, 0);
		break;
	case 1:
		ret = amdgpu_ras_feature_enable(adev, &data.head, 1);
		break;
	case 2:
		ret = amdgpu_ras_error_inject(adev, &data.inject);
		break;
	default:
		ret = -EINVAL;
		break;
	};

	if (ret)
		return -EINVAL;

	return size;
}

static const struct file_operations amdgpu_ras_debugfs_ctrl_ops = {
	.owner = THIS_MODULE,
	.read = NULL,
	.write = amdgpu_ras_debugfs_ctrl_write,
	.llseek = default_llseek
};

static ssize_t amdgpu_ras_sysfs_read(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct ras_manager *obj = container_of(attr, struct ras_manager, sysfs_attr);
	struct ras_query_if info = {
		.head = obj->head,
	};

	if (amdgpu_ras_error_query(obj->adev, &info))
		return -EINVAL;

	return snprintf(buf, PAGE_SIZE, "%s: %lu\n%s: %lu\n",
			"ue", info.ue_count,
			"ce", info.ce_count);
}

/* obj begin */

#define get_obj(obj) do { (obj)->use++; } while (0)
#define alive_obj(obj) ((obj)->use)

static inline void put_obj(struct ras_manager *obj)
{
	if (obj && --obj->use == 0)
		list_del(&obj->node);
	if (obj && obj->use < 0) {
		 DRM_ERROR("RAS ERROR: Unbalance obj(%s) use\n", obj->head.name);
	}
}

/* make one obj and return it. */
static struct ras_manager *amdgpu_ras_create_obj(struct amdgpu_device *adev,
		struct ras_common_if *head)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	struct ras_manager *obj;

	if (!con)
		return NULL;

	if (head->block >= AMDGPU_RAS_BLOCK_COUNT)
		return NULL;

	obj = &con->objs[head->block];
	/* already exist. return obj? */
	if (alive_obj(obj))
		return NULL;

	obj->head = *head;
	obj->adev = adev;
	list_add(&obj->node, &con->head);
	get_obj(obj);

	return obj;
}

/* return an obj equal to head, or the first when head is NULL */
static struct ras_manager *amdgpu_ras_find_obj(struct amdgpu_device *adev,
		struct ras_common_if *head)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	struct ras_manager *obj;
	int i;

	if (!con)
		return NULL;

	if (head) {
		if (head->block >= AMDGPU_RAS_BLOCK_COUNT)
			return NULL;

		obj = &con->objs[head->block];

		if (alive_obj(obj)) {
			WARN_ON(head->block != obj->head.block);
			return obj;
		}
	} else {
		for (i = 0; i < AMDGPU_RAS_BLOCK_COUNT; i++) {
			obj = &con->objs[i];
			if (alive_obj(obj)) {
				WARN_ON(i != obj->head.block);
				return obj;
			}
		}
	}

	return NULL;
}
/* obj end */

/* feature ctl begin */
static int amdgpu_ras_is_feature_allowed(struct amdgpu_device *adev,
		struct ras_common_if *head)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);

	return con->hw_supported & BIT(head->block);
}

static int amdgpu_ras_is_feature_enabled(struct amdgpu_device *adev,
		struct ras_common_if *head)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);

	return con->features & BIT(head->block);
}

/*
 * if obj is not created, then create one.
 * set feature enable flag.
 */
static int __amdgpu_ras_feature_enable(struct amdgpu_device *adev,
		struct ras_common_if *head, int enable)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	struct ras_manager *obj = amdgpu_ras_find_obj(adev, head);

	/* If hardware does not support ras, then do not create obj.
	 * But if hardware support ras, we can create the obj.
	 * Ras framework checks con->hw_supported to see if it need do
	 * corresponding initialization.
	 * IP checks con->support to see if it need disable ras.
	 */
	if (!amdgpu_ras_is_feature_allowed(adev, head))
		return 0;
	if (!(!!enable ^ !!amdgpu_ras_is_feature_enabled(adev, head)))
		return 0;

	if (enable) {
		if (!obj) {
			obj = amdgpu_ras_create_obj(adev, head);
			if (!obj)
				return -EINVAL;
		} else {
			/* In case we create obj somewhere else */
			get_obj(obj);
		}
		con->features |= BIT(head->block);
	} else {
		if (obj && amdgpu_ras_is_feature_enabled(adev, head)) {
			con->features &= ~BIT(head->block);
			put_obj(obj);
		}
	}

	return 0;
}

/* wrapper of psp_ras_enable_features */
int amdgpu_ras_feature_enable(struct amdgpu_device *adev,
		struct ras_common_if *head, bool enable)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	union ta_ras_cmd_input info;
	int ret;

	if (!con)
		return -EINVAL;

	if (!enable) {
		info.disable_features = (struct ta_ras_disable_features_input) {
			.block_id =  amdgpu_ras_block_to_ta(head->block),
			.error_type = amdgpu_ras_error_to_ta(head->type),
		};
	} else {
		info.enable_features = (struct ta_ras_enable_features_input) {
			.block_id =  amdgpu_ras_block_to_ta(head->block),
			.error_type = amdgpu_ras_error_to_ta(head->type),
		};
	}

	/* Do not enable if it is not allowed. */
	WARN_ON(enable && !amdgpu_ras_is_feature_allowed(adev, head));
	/* Are we alerady in that state we are going to set? */
	if (!(!!enable ^ !!amdgpu_ras_is_feature_enabled(adev, head)))
		return 0;

	ret = psp_ras_enable_features(&adev->psp, &info, enable);
	if (ret) {
		DRM_ERROR("RAS ERROR: %s %s feature failed ret %d\n",
				enable ? "enable":"disable",
				ras_block_str(head->block),
				ret);
		return -EINVAL;
	}

	/* setup the obj */
	__amdgpu_ras_feature_enable(adev, head, enable);

	return 0;
}

static int amdgpu_ras_disable_all_features(struct amdgpu_device *adev,
		bool bypass)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	struct ras_manager *obj, *tmp;

	list_for_each_entry_safe(obj, tmp, &con->head, node) {
		/* bypass psp.
		 * aka just release the obj and corresponding flags
		 */
		if (bypass) {
			if (__amdgpu_ras_feature_enable(adev, &obj->head, 0))
				break;
		} else {
			if (amdgpu_ras_feature_enable(adev, &obj->head, 0))
				break;
		}
	}

	return con->features;
}

static int amdgpu_ras_enable_all_features(struct amdgpu_device *adev,
		bool bypass)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	int ras_block_count = AMDGPU_RAS_BLOCK_COUNT;
	int i;
	const enum amdgpu_ras_error_type default_ras_type =
		AMDGPU_RAS_ERROR__NONE;

	for (i = 0; i < ras_block_count; i++) {
		struct ras_common_if head = {
			.block = i,
			.type = default_ras_type,
			.sub_block_index = 0,
		};
		strcpy(head.name, ras_block_str(i));
		if (bypass) {
			/*
			 * bypass psp. vbios enable ras for us.
			 * so just create the obj
			 */
			if (__amdgpu_ras_feature_enable(adev, &head, 1))
				break;
		} else {
			if (amdgpu_ras_feature_enable(adev, &head, 1))
				break;
		}
	}

	return con->features;
}
/* feature ctl end */

/* query/inject/cure begin */
int amdgpu_ras_error_query(struct amdgpu_device *adev,
		struct ras_query_if *info)
{
	struct ras_manager *obj = amdgpu_ras_find_obj(adev, &info->head);

	if (!obj)
		return -EINVAL;
	/* TODO might read the register to read the count */

	info->ue_count = obj->err_data.ue_count;
	info->ce_count = obj->err_data.ce_count;

	return 0;
}

/* wrapper of psp_ras_trigger_error */
int amdgpu_ras_error_inject(struct amdgpu_device *adev,
		struct ras_inject_if *info)
{
	struct ras_manager *obj = amdgpu_ras_find_obj(adev, &info->head);
	struct ta_ras_trigger_error_input block_info = {
		.block_id =  amdgpu_ras_block_to_ta(info->head.block),
		.inject_error_type = amdgpu_ras_error_to_ta(info->head.type),
		.sub_block_index = info->head.sub_block_index,
		.address = info->address,
		.value = info->value,
	};
	int ret = 0;

	if (!obj)
		return -EINVAL;

	ret = psp_ras_trigger_error(&adev->psp, &block_info);
	if (ret)
		DRM_ERROR("RAS ERROR: inject %s error failed ret %d\n",
				ras_block_str(info->head.block),
				ret);

	return ret;
}

int amdgpu_ras_error_cure(struct amdgpu_device *adev,
		struct ras_cure_if *info)
{
	/* psp fw has no cure interface for now. */
	return 0;
}

/* get the total error counts on all IPs */
int amdgpu_ras_query_error_count(struct amdgpu_device *adev,
		bool is_ce)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	struct ras_manager *obj;
	struct ras_err_data data = {0, 0};

	if (!con)
		return -EINVAL;

	list_for_each_entry(obj, &con->head, node) {
		struct ras_query_if info = {
			.head = obj->head,
		};

		if (amdgpu_ras_error_query(adev, &info))
			return -EINVAL;

		data.ce_count += info.ce_count;
		data.ue_count += info.ue_count;
	}

	return is_ce ? data.ce_count : data.ue_count;
}
/* query/inject/cure end */


/* sysfs begin */

static ssize_t amdgpu_ras_sysfs_features_read(struct device *dev,
		struct device_attribute *attr, char *buf)
{
	struct amdgpu_ras *con =
		container_of(attr, struct amdgpu_ras, features_attr);
	struct drm_device *ddev = dev_get_drvdata(dev);
	struct amdgpu_device *adev = ddev->dev_private;
	struct ras_common_if head;
	int ras_block_count = AMDGPU_RAS_BLOCK_COUNT;
	int i;
	ssize_t s;
	struct ras_manager *obj;

	s = scnprintf(buf, PAGE_SIZE, "feature mask: 0x%x\n", con->features);

	for (i = 0; i < ras_block_count; i++) {
		head.block = i;

		if (amdgpu_ras_is_feature_enabled(adev, &head)) {
			obj = amdgpu_ras_find_obj(adev, &head);
			s += scnprintf(&buf[s], PAGE_SIZE - s,
					"%s: %s\n",
					ras_block_str(i),
					ras_err_str(obj->head.type));
		} else
			s += scnprintf(&buf[s], PAGE_SIZE - s,
					"%s: disabled\n",
					ras_block_str(i));
	}

	return s;
}

static int amdgpu_ras_sysfs_create_feature_node(struct amdgpu_device *adev)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	struct attribute *attrs[] = {
		&con->features_attr.attr,
		NULL
	};
	struct attribute_group group = {
		.name = "ras",
		.attrs = attrs,
	};

	con->features_attr = (struct device_attribute) {
		.attr = {
			.name = "features",
			.mode = S_IRUGO,
		},
			.show = amdgpu_ras_sysfs_features_read,
	};
	sysfs_attr_init(attrs[0]);

	return sysfs_create_group(&adev->dev->kobj, &group);
}

static int amdgpu_ras_sysfs_remove_feature_node(struct amdgpu_device *adev)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	struct attribute *attrs[] = {
		&con->features_attr.attr,
		NULL
	};
	struct attribute_group group = {
		.name = "ras",
		.attrs = attrs,
	};

	sysfs_remove_group(&adev->dev->kobj, &group);

	return 0;
}

int amdgpu_ras_sysfs_create(struct amdgpu_device *adev,
		struct ras_fs_if *head)
{
	struct ras_manager *obj = amdgpu_ras_find_obj(adev, &head->head);

	if (!obj || obj->attr_inuse)
		return -EINVAL;

	get_obj(obj);

	memcpy(obj->fs_data.sysfs_name,
			head->sysfs_name,
			sizeof(obj->fs_data.sysfs_name));

	obj->sysfs_attr = (struct device_attribute){
		.attr = {
			.name = obj->fs_data.sysfs_name,
			.mode = S_IRUGO,
		},
			.show = amdgpu_ras_sysfs_read,
	};
	sysfs_attr_init(&obj->sysfs_attr.attr);

	if (sysfs_add_file_to_group(&adev->dev->kobj,
				&obj->sysfs_attr.attr,
				"ras")) {
		put_obj(obj);
		return -EINVAL;
	}

	obj->attr_inuse = 1;

	return 0;
}

int amdgpu_ras_sysfs_remove(struct amdgpu_device *adev,
		struct ras_common_if *head)
{
	struct ras_manager *obj = amdgpu_ras_find_obj(adev, head);

	if (!obj || !obj->attr_inuse)
		return -EINVAL;

	sysfs_remove_file_from_group(&adev->dev->kobj,
				&obj->sysfs_attr.attr,
				"ras");
	obj->attr_inuse = 0;
	put_obj(obj);

	return 0;
}

static int amdgpu_ras_sysfs_remove_all(struct amdgpu_device *adev)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	struct ras_manager *obj, *tmp;

	list_for_each_entry_safe(obj, tmp, &con->head, node) {
		amdgpu_ras_sysfs_remove(adev, &obj->head);
	}

	amdgpu_ras_sysfs_remove_feature_node(adev);

	return 0;
}
/* sysfs end */

/* debugfs begin */
static int amdgpu_ras_debugfs_create_ctrl_node(struct amdgpu_device *adev)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	struct drm_minor *minor = adev->ddev->primary;
	struct dentry *root = minor->debugfs_root, *dir;
	struct dentry *ent;

	dir = debugfs_create_dir("ras", root);
	if (IS_ERR(dir))
		return -EINVAL;

	con->dir = dir;

	ent = debugfs_create_file("ras_ctrl",
			S_IWUGO | S_IRUGO, con->dir,
			adev, &amdgpu_ras_debugfs_ctrl_ops);
	if (IS_ERR(ent)) {
		debugfs_remove(con->dir);
		return -EINVAL;
	}

	con->ent = ent;
	return 0;
}

int amdgpu_ras_debugfs_create(struct amdgpu_device *adev,
		struct ras_fs_if *head)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	struct ras_manager *obj = amdgpu_ras_find_obj(adev, &head->head);
	struct dentry *ent;

	if (!obj || obj->ent)
		return -EINVAL;

	get_obj(obj);

	memcpy(obj->fs_data.debugfs_name,
			head->debugfs_name,
			sizeof(obj->fs_data.debugfs_name));

	ent = debugfs_create_file(obj->fs_data.debugfs_name,
			S_IWUGO | S_IRUGO, con->dir,
			obj, &amdgpu_ras_debugfs_ops);

	if (IS_ERR(ent))
		return -EINVAL;

	obj->ent = ent;

	return 0;
}

int amdgpu_ras_debugfs_remove(struct amdgpu_device *adev,
		struct ras_common_if *head)
{
	struct ras_manager *obj = amdgpu_ras_find_obj(adev, head);

	if (!obj || !obj->ent)
		return 0;

	debugfs_remove(obj->ent);
	obj->ent = NULL;
	put_obj(obj);

	return 0;
}

static int amdgpu_ras_debugfs_remove_all(struct amdgpu_device *adev)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	struct ras_manager *obj, *tmp;

	list_for_each_entry_safe(obj, tmp, &con->head, node) {
		amdgpu_ras_debugfs_remove(adev, &obj->head);
	}

	debugfs_remove(con->ent);
	debugfs_remove(con->dir);
	con->dir = NULL;
	con->ent = NULL;

	return 0;
}
/* debugfs end */

/* ras fs */

static int amdgpu_ras_fs_init(struct amdgpu_device *adev)
{
	amdgpu_ras_sysfs_create_feature_node(adev);
	amdgpu_ras_debugfs_create_ctrl_node(adev);

	return 0;
}

static int amdgpu_ras_fs_fini(struct amdgpu_device *adev)
{
	amdgpu_ras_debugfs_remove_all(adev);
	amdgpu_ras_sysfs_remove_all(adev);
	return 0;
}
/* ras fs end */

/* ih begin */
static void amdgpu_ras_interrupt_handler(struct ras_manager *obj)
{
	struct ras_ih_data *data = &obj->ih_data;
	struct amdgpu_iv_entry entry;
	int ret;

	while (data->rptr != data->wptr) {
		rmb();
		memcpy(&entry, &data->ring[data->rptr],
				data->element_size);

		wmb();
		data->rptr = (data->aligned_element_size +
				data->rptr) % data->ring_size;

		/* Let IP handle its data, maybe we need get the output
		 * from the callback to udpate the error type/count, etc
		 */
		if (data->cb) {
			ret = data->cb(obj->adev, &entry);
			/* ue will trigger an interrupt, and in that case
			 * we need do a reset to recovery the whole system.
			 * But leave IP do that recovery, here we just dispatch
			 * the error.
			 */
			if (ret == AMDGPU_RAS_UE) {
				obj->err_data.ue_count++;
			}
			/* Might need get ce count by register, but not all IP
			 * saves ce count, some IP just use one bit or two bits
			 * to indicate ce happened.
			 */
		}
	}
}

static void amdgpu_ras_interrupt_process_handler(struct work_struct *work)
{
	struct ras_ih_data *data =
		container_of(work, struct ras_ih_data, ih_work);
	struct ras_manager *obj =
		container_of(data, struct ras_manager, ih_data);

	amdgpu_ras_interrupt_handler(obj);
}

int amdgpu_ras_interrupt_dispatch(struct amdgpu_device *adev,
		struct ras_dispatch_if *info)
{
	struct ras_manager *obj = amdgpu_ras_find_obj(adev, &info->head);
	struct ras_ih_data *data = &obj->ih_data;

	if (!obj)
		return -EINVAL;

	if (data->inuse == 0)
		return 0;

	/* Might be overflow... */
	memcpy(&data->ring[data->wptr], info->entry,
			data->element_size);

	wmb();
	data->wptr = (data->aligned_element_size +
			data->wptr) % data->ring_size;

	schedule_work(&data->ih_work);

	return 0;
}

int amdgpu_ras_interrupt_remove_handler(struct amdgpu_device *adev,
		struct ras_ih_if *info)
{
	struct ras_manager *obj = amdgpu_ras_find_obj(adev, &info->head);
	struct ras_ih_data *data;

	if (!obj)
		return -EINVAL;

	data = &obj->ih_data;
	if (data->inuse == 0)
		return 0;

	cancel_work_sync(&data->ih_work);

	kfree(data->ring);
	memset(data, 0, sizeof(*data));
	put_obj(obj);

	return 0;
}

int amdgpu_ras_interrupt_add_handler(struct amdgpu_device *adev,
		struct ras_ih_if *info)
{
	struct ras_manager *obj = amdgpu_ras_find_obj(adev, &info->head);
	struct ras_ih_data *data;

	if (!obj) {
		/* in case we registe the IH before enable ras feature */
		obj = amdgpu_ras_create_obj(adev, &info->head);
		if (!obj)
			return -EINVAL;
	} else
		get_obj(obj);

	data = &obj->ih_data;
	/* add the callback.etc */
	*data = (struct ras_ih_data) {
		.inuse = 0,
		.cb = info->cb,
		.element_size = sizeof(struct amdgpu_iv_entry),
		.rptr = 0,
		.wptr = 0,
	};

	INIT_WORK(&data->ih_work, amdgpu_ras_interrupt_process_handler);

	data->aligned_element_size = ALIGN(data->element_size, 8);
	/* the ring can store 64 iv entries. */
	data->ring_size = 64 * data->aligned_element_size;
	data->ring = kmalloc(data->ring_size, GFP_KERNEL);
	if (!data->ring) {
		put_obj(obj);
		return -ENOMEM;
	}

	/* IH is ready */
	data->inuse = 1;

	return 0;
}

static int amdgpu_ras_interrupt_remove_all(struct amdgpu_device *adev)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	struct ras_manager *obj, *tmp;

	list_for_each_entry_safe(obj, tmp, &con->head, node) {
		struct ras_ih_if info = {
			.head = obj->head,
		};
		amdgpu_ras_interrupt_remove_handler(adev, &info);
	}

	return 0;
}
/* ih end */

/* recovery begin */
static void amdgpu_ras_do_recovery(struct work_struct *work)
{
	struct amdgpu_ras *ras =
		container_of(work, struct amdgpu_ras, recovery_work);

	amdgpu_device_gpu_recover(ras->adev, 0);
	atomic_set(&ras->in_recovery, 0);
}

static int amdgpu_ras_release_vram(struct amdgpu_device *adev,
		struct amdgpu_bo **bo_ptr)
{
	/* no need to free it actually. */
	amdgpu_bo_free_kernel(bo_ptr, NULL, NULL);
	return 0;
}

/* reserve vram with size@offset */
static int amdgpu_ras_reserve_vram(struct amdgpu_device *adev,
		uint64_t offset, uint64_t size,
		struct amdgpu_bo **bo_ptr)
{
	struct ttm_operation_ctx ctx = { false, false };
	struct amdgpu_bo_param bp;
	int r = 0;
	int i;
	struct amdgpu_bo *bo;

	if (bo_ptr)
		*bo_ptr = NULL;
	memset(&bp, 0, sizeof(bp));
	bp.size = size;
	bp.byte_align = PAGE_SIZE;
	bp.domain = AMDGPU_GEM_DOMAIN_VRAM;
	bp.flags = AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS |
		AMDGPU_GEM_CREATE_NO_CPU_ACCESS;
	bp.type = ttm_bo_type_kernel;
	bp.resv = NULL;

	r = amdgpu_bo_create(adev, &bp, &bo);
	if (r)
		return -EINVAL;

	r = amdgpu_bo_reserve(bo, false);
	if (r)
		goto error_reserve;

	offset = ALIGN(offset, PAGE_SIZE);
	for (i = 0; i < bo->placement.num_placement; ++i) {
		bo->placements[i].fpfn = offset >> PAGE_SHIFT;
		bo->placements[i].lpfn = (offset + size) >> PAGE_SHIFT;
	}

	ttm_bo_mem_put(&bo->tbo, &bo->tbo.mem);
	r = ttm_bo_mem_space(&bo->tbo, &bo->placement, &bo->tbo.mem, &ctx);
	if (r)
		goto error_pin;

	r = amdgpu_bo_pin_restricted(bo,
			AMDGPU_GEM_DOMAIN_VRAM,
			offset,
			offset + size);
	if (r)
		goto error_pin;

	if (bo_ptr)
		*bo_ptr = bo;

	amdgpu_bo_unreserve(bo);
	return r;

error_pin:
	amdgpu_bo_unreserve(bo);
error_reserve:
	amdgpu_bo_unref(&bo);
	return r;
}

/* alloc/realloc bps array */
static int amdgpu_ras_realloc_eh_data_space(struct amdgpu_device *adev,
		struct ras_err_handler_data *data, int pages)
{
	unsigned int old_space = data->count + data->space_left;
	unsigned int new_space = old_space + pages;
	unsigned int align_space = ALIGN(new_space, 1024);
	void *tmp = kmalloc(align_space * sizeof(*data->bps), GFP_KERNEL);

	if (!tmp)
		return -ENOMEM;

	if (data->bps) {
		memcpy(tmp, data->bps,
				data->count * sizeof(*data->bps));
		kfree(data->bps);
	}

	data->bps = tmp;
	data->space_left += align_space - old_space;
	return 0;
}

/* it deal with vram only. */
int amdgpu_ras_add_bad_pages(struct amdgpu_device *adev,
		unsigned long *bps, int pages)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	struct ras_err_handler_data *data;
	int i = pages;
	int ret = 0;

	if (!con || !con->eh_data || !bps || pages <= 0)
		return 0;

	mutex_lock(&con->recovery_lock);
	data = con->eh_data;
	if (!data)
		goto out;

	if (data->space_left <= pages)
		if (amdgpu_ras_realloc_eh_data_space(adev, data, pages)) {
			ret = -ENOMEM;
			goto out;
		}

	while (i--)
		data->bps[data->count++].bp = bps[i];

	data->space_left -= pages;
out:
	mutex_unlock(&con->recovery_lock);

	return ret;
}

/* called in gpu recovery/init */
int amdgpu_ras_reserve_bad_pages(struct amdgpu_device *adev)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	struct ras_err_handler_data *data;
	uint64_t bp;
	struct amdgpu_bo *bo;
	int i;

	if (!con || !con->eh_data)
		return 0;

	mutex_lock(&con->recovery_lock);
	data = con->eh_data;
	if (!data)
		goto out;
	/* reserve vram at driver post stage. */
	for (i = data->last_reserved; i < data->count; i++) {
		bp = data->bps[i].bp;

		if (amdgpu_ras_reserve_vram(adev, bp << PAGE_SHIFT,
					PAGE_SIZE, &bo))
			DRM_ERROR("RAS ERROR: reserve vram %llx fail\n", bp);

		data->bps[i].bo = bo;
		data->last_reserved = i + 1;
	}
out:
	mutex_unlock(&con->recovery_lock);
	return 0;
}

/* called when driver unload */
static int amdgpu_ras_release_bad_pages(struct amdgpu_device *adev)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	struct ras_err_handler_data *data;
	struct amdgpu_bo *bo;
	int i;

	if (!con || !con->eh_data)
		return 0;

	mutex_lock(&con->recovery_lock);
	data = con->eh_data;
	if (!data)
		goto out;

	for (i = data->last_reserved - 1; i >= 0; i--) {
		bo = data->bps[i].bo;

		amdgpu_ras_release_vram(adev, &bo);

		data->bps[i].bo = bo;
		data->last_reserved = i;
	}
out:
	mutex_unlock(&con->recovery_lock);
	return 0;
}

static int amdgpu_ras_save_bad_pages(struct amdgpu_device *adev)
{
	/* TODO
	 * write the array to eeprom when SMU disabled.
	 */
	return 0;
}

static int amdgpu_ras_load_bad_pages(struct amdgpu_device *adev)
{
	/* TODO
	 * read the array to eeprom when SMU disabled.
	 */
	return 0;
}

static int amdgpu_ras_recovery_init(struct amdgpu_device *adev)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	struct ras_err_handler_data **data = &con->eh_data;

	*data = kmalloc(sizeof(**data),
			GFP_KERNEL|__GFP_ZERO);
	if (!*data)
		return -ENOMEM;

	mutex_init(&con->recovery_lock);
	INIT_WORK(&con->recovery_work, amdgpu_ras_do_recovery);
	atomic_set(&con->in_recovery, 0);
	con->adev = adev;

	amdgpu_ras_load_bad_pages(adev);
	amdgpu_ras_reserve_bad_pages(adev);

	return 0;
}

static int amdgpu_ras_recovery_fini(struct amdgpu_device *adev)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	struct ras_err_handler_data *data = con->eh_data;

	cancel_work_sync(&con->recovery_work);
	amdgpu_ras_save_bad_pages(adev);
	amdgpu_ras_release_bad_pages(adev);

	mutex_lock(&con->recovery_lock);
	con->eh_data = NULL;
	kfree(data->bps);
	kfree(data);
	mutex_unlock(&con->recovery_lock);

	return 0;
}
/* recovery end */

/*
 * check hardware's ras ability which will be saved in hw_supported.
 * if hardware does not support ras, we can skip some ras initializtion and
 * forbid some ras operations from IP.
 * if software itself, say boot parameter, limit the ras ability. We still
 * need allow IP do some limited operations, like disable. In such case,
 * we have to initialize ras as normal. but need check if operation is
 * allowed or not in each function.
 */
static void amdgpu_ras_check_supported(struct amdgpu_device *adev,
		uint32_t *hw_supported, uint32_t *supported)
{
	*hw_supported = 0;
	*supported = 0;

	if (amdgpu_sriov_vf(adev) ||
			adev->asic_type != CHIP_VEGA20)
		return;

	if (adev->is_atom_fw &&
			(amdgpu_atomfirmware_mem_ecc_supported(adev) ||
			 amdgpu_atomfirmware_sram_ecc_supported(adev)))
		*hw_supported = AMDGPU_RAS_BLOCK_MASK;

	*supported = amdgpu_ras_enable == 0 ?
				0 : *hw_supported & amdgpu_ras_mask;
}

int amdgpu_ras_init(struct amdgpu_device *adev)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);

	if (con)
		return 0;

	con = kmalloc(sizeof(struct amdgpu_ras) +
			sizeof(struct ras_manager) * AMDGPU_RAS_BLOCK_COUNT,
			GFP_KERNEL|__GFP_ZERO);
	if (!con)
		return -ENOMEM;

	con->objs = (struct ras_manager *)(con + 1);

	amdgpu_ras_set_context(adev, con);

	amdgpu_ras_check_supported(adev, &con->hw_supported,
			&con->supported);
	con->features = 0;
	INIT_LIST_HEAD(&con->head);
	/* Might need get this flag from vbios. */
	con->flags = RAS_DEFAULT_FLAGS;

	if (amdgpu_ras_recovery_init(adev))
		goto recovery_out;

	amdgpu_ras_mask &= AMDGPU_RAS_BLOCK_MASK;

	if (amdgpu_ras_fs_init(adev))
		goto fs_out;

	amdgpu_ras_self_test(adev);

	DRM_INFO("RAS INFO: ras initialized successfully, "
			"hardware ability[%x] ras_mask[%x]\n",
			con->hw_supported, con->supported);
	return 0;
fs_out:
	amdgpu_ras_recovery_fini(adev);
recovery_out:
	amdgpu_ras_set_context(adev, NULL);
	kfree(con);

	return -EINVAL;
}

/* do some init work after IP late init as dependence */
void amdgpu_ras_post_init(struct amdgpu_device *adev)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
	struct ras_manager *obj, *tmp;

	if (!con)
		return;

	if (con->flags & AMDGPU_RAS_FLAG_INIT_BY_VBIOS) {
		/* Set up all other IPs which are not implemented. There is a
		 * tricky thing that IP's actual ras error type should be
		 * MULTI_UNCORRECTABLE, but as driver does not handle it, so
		 * ERROR_NONE make sense anyway.
		 */
		amdgpu_ras_enable_all_features(adev, 1);

		/* We enable ras on all hw_supported block, but as boot
		 * parameter might disable some of them and one or more IP has
		 * not implemented yet. So we disable them on behalf.
		 */
		list_for_each_entry_safe(obj, tmp, &con->head, node) {
			if (!amdgpu_ras_is_supported(adev, obj->head.block)) {
				amdgpu_ras_feature_enable(adev, &obj->head, 0);
				/* there should be no any reference. */
				WARN_ON(alive_obj(obj));
			}
		}
	}
}

/* do some fini work before IP fini as dependence */
int amdgpu_ras_pre_fini(struct amdgpu_device *adev)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);

	if (!con)
		return 0;

	/* Need disable ras on all IPs here before ip [hw/sw]fini */
	amdgpu_ras_disable_all_features(adev, 0);
	amdgpu_ras_recovery_fini(adev);
	return 0;
}

int amdgpu_ras_fini(struct amdgpu_device *adev)
{
	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);

	if (!con)
		return 0;

	amdgpu_ras_fs_fini(adev);
	amdgpu_ras_interrupt_remove_all(adev);

	WARN(con->features, "Feature mask is not cleared");

	if (con->features)
		amdgpu_ras_disable_all_features(adev, 1);

	amdgpu_ras_set_context(adev, NULL);
	kfree(con);

	return 0;
}