/*
 * Copyright (C) 2016-2017 Dell, Inc.
 * Copyright (C) 2016 Hewlett Packard Enterprise Development LP
 * Copyright (c) 2016, Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU Lesser General Public License,
 * version 2.1, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
 * more details.
 */
#include <stdlib.h>
#include <limits.h>
#include <util/log.h>
#include <ndctl/libndctl.h>
#include "private.h"
#include "msft.h"

#define CMD_MSFT(_c) ((_c)->msft)
#define CMD_MSFT_SMART(_c) (CMD_MSFT(_c)->u.smart.data)

static struct ndctl_cmd *msft_dimm_cmd_new_smart(struct ndctl_dimm *dimm)
{
	struct ndctl_bus *bus = ndctl_dimm_get_bus(dimm);
	struct ndctl_ctx *ctx = ndctl_bus_get_ctx(bus);
	struct ndctl_cmd *cmd;
	size_t size;
	struct ndn_pkg_msft *msft;

	if (!ndctl_dimm_is_cmd_supported(dimm, ND_CMD_CALL)) {
		dbg(ctx, "unsupported cmd\n");
		return NULL;
	}

	size = sizeof(*cmd) + sizeof(struct ndn_pkg_msft);
	cmd = calloc(1, size);
	if (!cmd)
		return NULL;

	cmd->dimm = dimm;
	ndctl_cmd_ref(cmd);
	cmd->type = ND_CMD_CALL;
	cmd->size = size;
	cmd->status = 1;

	msft = CMD_MSFT(cmd);
	msft->gen.nd_family = NVDIMM_FAMILY_MSFT;
	msft->gen.nd_command = NDN_MSFT_CMD_SMART;
	msft->gen.nd_fw_size = 0;
	msft->gen.nd_size_in = offsetof(struct ndn_msft_smart, status);
	msft->gen.nd_size_out = sizeof(msft->u.smart);
	msft->u.smart.status = 0;

	cmd->firmware_status = &msft->u.smart.status;

	return cmd;
}

static int msft_smart_valid(struct ndctl_cmd *cmd)
{
	if (cmd->type != ND_CMD_CALL ||
	    cmd->size != sizeof(*cmd) + sizeof(struct ndn_pkg_msft) ||
	    CMD_MSFT(cmd)->gen.nd_family != NVDIMM_FAMILY_MSFT ||
	    CMD_MSFT(cmd)->gen.nd_command != NDN_MSFT_CMD_SMART ||
	    cmd->status != 0)
		return cmd->status < 0 ? cmd->status : -EINVAL;
	return 0;
}

static unsigned int msft_cmd_smart_get_flags(struct ndctl_cmd *cmd)
{
	if (msft_smart_valid(cmd) < 0)
		return UINT_MAX;

	/* below health data can be retrieved via MSFT _DSM function 11 */
	return NDN_MSFT_SMART_HEALTH_VALID |
		NDN_MSFT_SMART_TEMP_VALID |
		NDN_MSFT_SMART_USED_VALID;
}

static unsigned int num_set_bit_health(__u16 num)
{
	int i;
	__u16 n = num & 0x7FFF;
	unsigned int count = 0;

	for (i = 0; i < 15; i++)
		if (!!(n & (1 << i)))
			count++;

	return count;
}

static unsigned int msft_cmd_smart_get_health(struct ndctl_cmd *cmd)
{
	unsigned int health;
	unsigned int num;

	if (msft_smart_valid(cmd) < 0)
		return UINT_MAX;

	num = num_set_bit_health(CMD_MSFT_SMART(cmd)->health);
	if (num == 0)
		health = 0;
	else if (num < 2)
		health = ND_SMART_NON_CRITICAL_HEALTH;
	else if (num < 3)
		health = ND_SMART_CRITICAL_HEALTH;
	else
		health = ND_SMART_FATAL_HEALTH;

	return health;
}

static unsigned int msft_cmd_smart_get_temperature(struct ndctl_cmd *cmd)
{
	if (msft_smart_valid(cmd) < 0)
		return UINT_MAX;

	return CMD_MSFT_SMART(cmd)->temp * 16;
}

static unsigned int msft_cmd_smart_get_life_used(struct ndctl_cmd *cmd)
{
	if (msft_smart_valid(cmd) < 0)
		return UINT_MAX;

	return 100 - CMD_MSFT_SMART(cmd)->nvm_lifetime;
}

struct ndctl_smart_ops * const msft_smart_ops = &(struct ndctl_smart_ops) {
	.new_smart = msft_dimm_cmd_new_smart,
	.smart_get_flags = msft_cmd_smart_get_flags,
	.smart_get_health = msft_cmd_smart_get_health,
	.smart_get_temperature = msft_cmd_smart_get_temperature,
	.smart_get_life_used = msft_cmd_smart_get_life_used,
};