// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2003-2022, Intel Corporation. All rights reserved.
 * Intel Management Engine Interface (Intel MEI) Linux driver
 */
#include <linux/export.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>

#include <linux/mei.h>

#include "mei_dev.h"
#include "hbm.h"
#include "client.h"

static const char *mei_hbm_status_str(enum mei_hbm_status status)
{
#define MEI_HBM_STATUS(status) case MEI_HBMS_##status: return #status
        switch (status) {
        MEI_HBM_STATUS(SUCCESS);
        MEI_HBM_STATUS(CLIENT_NOT_FOUND);
        MEI_HBM_STATUS(ALREADY_EXISTS);
        MEI_HBM_STATUS(REJECTED);
        MEI_HBM_STATUS(INVALID_PARAMETER);
        MEI_HBM_STATUS(NOT_ALLOWED);
        MEI_HBM_STATUS(ALREADY_STARTED);
        MEI_HBM_STATUS(NOT_STARTED);
        default: return "unknown";
        }
#undef MEI_HBM_STATUS
};

static const char *mei_cl_conn_status_str(enum mei_cl_connect_status status)
{
#define MEI_CL_CS(status) case MEI_CL_CONN_##status: return #status
        switch (status) {
        MEI_CL_CS(SUCCESS);
        MEI_CL_CS(NOT_FOUND);
        MEI_CL_CS(ALREADY_STARTED);
        MEI_CL_CS(OUT_OF_RESOURCES);
        MEI_CL_CS(MESSAGE_SMALL);
        MEI_CL_CS(NOT_ALLOWED);
        default: return "unknown";
        }
#undef MEI_CL_CCS
}

const char *mei_hbm_state_str(enum mei_hbm_state state)
{
#define MEI_HBM_STATE(state) case MEI_HBM_##state: return #state
        switch (state) {
        MEI_HBM_STATE(IDLE);
        MEI_HBM_STATE(STARTING);
        MEI_HBM_STATE(STARTED);
        MEI_HBM_STATE(DR_SETUP);
        MEI_HBM_STATE(ENUM_CLIENTS);
        MEI_HBM_STATE(CLIENT_PROPERTIES);
        MEI_HBM_STATE(STOPPED);
        default:
                return "unknown";
        }
#undef MEI_HBM_STATE
}

/**
 * mei_cl_conn_status_to_errno - convert client connect response
 * status to error code
 *
 * @status: client connect response status
 *
 * Return: corresponding error code
 */
static int mei_cl_conn_status_to_errno(enum mei_cl_connect_status status)
{
        switch (status) {
        case MEI_CL_CONN_SUCCESS:          return 0;
        case MEI_CL_CONN_NOT_FOUND:        return -ENOTTY;
        case MEI_CL_CONN_ALREADY_STARTED:  return -EBUSY;
        case MEI_CL_CONN_OUT_OF_RESOURCES: return -EBUSY;
        case MEI_CL_CONN_MESSAGE_SMALL:    return -EINVAL;
        case MEI_CL_CONN_NOT_ALLOWED:      return -EBUSY;
        default:                           return -EINVAL;
        }
}

/**
 * mei_hbm_write_message - wrapper for sending hbm messages.
 *
 * @dev: mei device
 * @hdr: mei header
 * @data: payload
 *
 * Return: >=0 on success, <0 on error
 */
static inline int mei_hbm_write_message(struct mei_device *dev,
                                        struct mei_msg_hdr *hdr,
                                        const void *data)
{
        return mei_write_message(dev, hdr, sizeof(*hdr), data, hdr->length);
}

/**
 * mei_hbm_idle - set hbm to idle state
 *
 * @dev: the device structure
 */
void mei_hbm_idle(struct mei_device *dev)
{
        dev->init_clients_timer = 0;
        dev->hbm_state = MEI_HBM_IDLE;
}

/**
 * mei_hbm_reset - reset hbm counters and book keeping data structures
 *
 * @dev: the device structure
 */
void mei_hbm_reset(struct mei_device *dev)
{
        mei_me_cl_rm_all(dev);

        mei_hbm_idle(dev);
}

/**
 * mei_hbm_hdr - construct hbm header
 *
 * @mei_hdr: hbm header
 * @length: payload length
 */

static inline void mei_hbm_hdr(struct mei_msg_hdr *mei_hdr, size_t length)
{
        memset(mei_hdr, 0, sizeof(*mei_hdr));
        mei_hdr->length = length;
        mei_hdr->msg_complete = 1;
}

/**
 * mei_hbm_cl_hdr - construct client hbm header
 *
 * @cl: client
 * @hbm_cmd: host bus message command
 * @buf: buffer for cl header
 * @len: buffer length
 */
static inline
void mei_hbm_cl_hdr(struct mei_cl *cl, u8 hbm_cmd, void *buf, size_t len)
{
        struct mei_hbm_cl_cmd *cmd = buf;

        memset(cmd, 0, len);

        cmd->hbm_cmd = hbm_cmd;
        cmd->host_addr = mei_cl_host_addr(cl);
        cmd->me_addr = mei_cl_me_id(cl);
}

/**
 * mei_hbm_cl_write - write simple hbm client message
 *
 * @dev: the device structure
 * @cl: client
 * @hbm_cmd: host bus message command
 * @buf: message buffer
 * @len: buffer length
 *
 * Return: 0 on success, <0 on failure.
 */
static inline int mei_hbm_cl_write(struct mei_device *dev, struct mei_cl *cl,
                                   u8 hbm_cmd, void *buf, size_t len)
{
        struct mei_msg_hdr mei_hdr;

        mei_hbm_hdr(&mei_hdr, len);
        mei_hbm_cl_hdr(cl, hbm_cmd, buf, len);

        return mei_hbm_write_message(dev, &mei_hdr, buf);
}

/**
 * mei_hbm_cl_addr_equal - check if the client's and
 *      the message address match
 *
 * @cl: client
 * @cmd: hbm client message
 *
 * Return: true if addresses are the same
 */
static inline
bool mei_hbm_cl_addr_equal(struct mei_cl *cl, struct mei_hbm_cl_cmd *cmd)
{
        return  mei_cl_host_addr(cl) == cmd->host_addr &&
                mei_cl_me_id(cl) == cmd->me_addr;
}

/**
 * mei_hbm_cl_find_by_cmd - find recipient client
 *
 * @dev: the device structure
 * @buf: a buffer with hbm cl command
 *
 * Return: the recipient client or NULL if not found
 */
static inline
struct mei_cl *mei_hbm_cl_find_by_cmd(struct mei_device *dev, void *buf)
{
        struct mei_hbm_cl_cmd *cmd = (struct mei_hbm_cl_cmd *)buf;
        struct mei_cl *cl;

        list_for_each_entry(cl, &dev->file_list, link)
                if (mei_hbm_cl_addr_equal(cl, cmd))
                        return cl;
        return NULL;
}


/**
 * mei_hbm_start_wait - wait for start response message.
 *
 * @dev: the device structure
 *
 * Return: 0 on success and < 0 on failure
 */
int mei_hbm_start_wait(struct mei_device *dev)
{
        int ret;

        if (dev->hbm_state > MEI_HBM_STARTING)
                return 0;

        mutex_unlock(&dev->device_lock);
        ret = wait_event_timeout(dev->wait_hbm_start,
                        dev->hbm_state != MEI_HBM_STARTING,
                        dev->timeouts.hbm);
        mutex_lock(&dev->device_lock);

        if (ret == 0 && (dev->hbm_state <= MEI_HBM_STARTING)) {
                dev->hbm_state = MEI_HBM_IDLE;
                dev_err(&dev->dev, "waiting for mei start failed\n");
                return -ETIME;
        }
        return 0;
}

/**
 * mei_hbm_start_req - sends start request message.
 *
 * @dev: the device structure
 *
 * Return: 0 on success and < 0 on failure
 */
int mei_hbm_start_req(struct mei_device *dev)
{
        struct mei_msg_hdr mei_hdr;
        struct hbm_host_version_request req;
        int ret;

        mei_hbm_reset(dev);

        mei_hbm_hdr(&mei_hdr, sizeof(req));

        /* host start message */
        memset(&req, 0, sizeof(req));
        req.hbm_cmd = HOST_START_REQ_CMD;
        req.host_version.major_version = HBM_MAJOR_VERSION;
        req.host_version.minor_version = HBM_MINOR_VERSION;

        dev->hbm_state = MEI_HBM_IDLE;
        ret = mei_hbm_write_message(dev, &mei_hdr, &req);
        if (ret) {
                dev_err(&dev->dev, "version message write failed: ret = %d\n", ret);
                return ret;
        }

        dev->hbm_state = MEI_HBM_STARTING;
        dev->init_clients_timer = dev->timeouts.client_init;
        mei_schedule_stall_timer(dev);
        return 0;
}

/**
 * mei_hbm_dma_setup_req() - setup DMA request
 * @dev: the device structure
 *
 * Return: 0 on success and < 0 on failure
 */
static int mei_hbm_dma_setup_req(struct mei_device *dev)
{
        struct mei_msg_hdr mei_hdr;
        struct hbm_dma_setup_request req;
        unsigned int i;
        int ret;

        mei_hbm_hdr(&mei_hdr, sizeof(req));

        memset(&req, 0, sizeof(req));
        req.hbm_cmd = MEI_HBM_DMA_SETUP_REQ_CMD;
        for (i = 0; i < DMA_DSCR_NUM; i++) {
                phys_addr_t paddr;

                paddr = dev->dr_dscr[i].daddr;
                req.dma_dscr[i].addr_hi = upper_32_bits(paddr);
                req.dma_dscr[i].addr_lo = lower_32_bits(paddr);
                req.dma_dscr[i].size = dev->dr_dscr[i].size;
        }

        mei_dma_ring_reset(dev);

        ret = mei_hbm_write_message(dev, &mei_hdr, &req);
        if (ret) {
                dev_err(&dev->dev, "dma setup request write failed: ret = %d.\n", ret);
                return ret;
        }

        dev->hbm_state = MEI_HBM_DR_SETUP;
        dev->init_clients_timer = dev->timeouts.client_init;
        mei_schedule_stall_timer(dev);
        return 0;
}

/**
 * mei_hbm_capabilities_req - request capabilities
 *
 * @dev: the device structure
 *
 * Return: 0 on success and < 0 on failure
 */
static int mei_hbm_capabilities_req(struct mei_device *dev)
{
        struct mei_msg_hdr mei_hdr;
        struct hbm_capability_request req;
        int ret;

        mei_hbm_hdr(&mei_hdr, sizeof(req));

        memset(&req, 0, sizeof(req));
        req.hbm_cmd = MEI_HBM_CAPABILITIES_REQ_CMD;
        if (dev->hbm_f_vt_supported)
                req.capability_requested[0] |= HBM_CAP_VT;

        if (dev->hbm_f_cd_supported)
                req.capability_requested[0] |= HBM_CAP_CD;

        if (dev->hbm_f_gsc_supported)
                req.capability_requested[0] |= HBM_CAP_GSC;

        ret = mei_hbm_write_message(dev, &mei_hdr, &req);
        if (ret) {
                dev_err(&dev->dev, "capabilities request write failed: ret = %d.\n", ret);
                return ret;
        }

        dev->hbm_state = MEI_HBM_CAP_SETUP;
        dev->init_clients_timer = dev->timeouts.client_init;
        mei_schedule_stall_timer(dev);
        return 0;
}

/**
 * mei_hbm_enum_clients_req - sends enumeration client request message.
 *
 * @dev: the device structure
 *
 * Return: 0 on success and < 0 on failure
 */
static int mei_hbm_enum_clients_req(struct mei_device *dev)
{
        struct mei_msg_hdr mei_hdr;
        struct hbm_host_enum_request req;
        int ret;

        /* enumerate clients */
        mei_hbm_hdr(&mei_hdr, sizeof(req));

        memset(&req, 0, sizeof(req));
        req.hbm_cmd = HOST_ENUM_REQ_CMD;
        req.flags |= dev->hbm_f_dc_supported ? MEI_HBM_ENUM_F_ALLOW_ADD : 0;
        req.flags |= dev->hbm_f_ie_supported ?
                          MEI_HBM_ENUM_F_IMMEDIATE_ENUM : 0;

        ret = mei_hbm_write_message(dev, &mei_hdr, &req);
        if (ret) {
                dev_err(&dev->dev, "enumeration request write failed: ret = %d.\n", ret);
                return ret;
        }
        dev->hbm_state = MEI_HBM_ENUM_CLIENTS;
        dev->init_clients_timer = dev->timeouts.client_init;
        mei_schedule_stall_timer(dev);
        return 0;
}

/**
 * mei_hbm_me_cl_add - add new me client to the list
 *
 * @dev: the device structure
 * @res: hbm property response
 *
 * Return: 0 on success and -ENOMEM on allocation failure
 */

static int mei_hbm_me_cl_add(struct mei_device *dev,
                             struct hbm_props_response *res)
{
        struct mei_me_client *me_cl;
        const uuid_le *uuid = &res->client_properties.protocol_name;

        mei_me_cl_rm_by_uuid(dev, uuid);

        me_cl = kzalloc_obj(*me_cl);
        if (!me_cl)
                return -ENOMEM;

        mei_me_cl_init(me_cl);

        me_cl->props = res->client_properties;
        me_cl->client_id = res->me_addr;
        me_cl->tx_flow_ctrl_creds = 0;

        mei_me_cl_add(dev, me_cl);

        return 0;
}

/**
 * mei_hbm_add_cl_resp - send response to fw on client add request
 *
 * @dev: the device structure
 * @addr: me address
 * @status: response status
 *
 * Return: 0 on success and < 0 on failure
 */
static int mei_hbm_add_cl_resp(struct mei_device *dev, u8 addr, u8 status)
{
        struct mei_msg_hdr mei_hdr;
        struct hbm_add_client_response resp;
        int ret;

        dev_dbg(&dev->dev, "adding client response\n");

        mei_hbm_hdr(&mei_hdr, sizeof(resp));

        memset(&resp, 0, sizeof(resp));
        resp.hbm_cmd = MEI_HBM_ADD_CLIENT_RES_CMD;
        resp.me_addr = addr;
        resp.status  = status;

        ret = mei_hbm_write_message(dev, &mei_hdr, &resp);
        if (ret)
                dev_err(&dev->dev, "add client response write failed: ret = %d\n", ret);
        return ret;
}

/**
 * mei_hbm_fw_add_cl_req - request from the fw to add a client
 *
 * @dev: the device structure
 * @req: add client request
 *
 * Return: 0 on success and < 0 on failure
 */
static int mei_hbm_fw_add_cl_req(struct mei_device *dev,
                              struct hbm_add_client_request *req)
{
        int ret;
        u8 status = MEI_HBMS_SUCCESS;

        BUILD_BUG_ON(sizeof(struct hbm_add_client_request) !=
                        sizeof(struct hbm_props_response));

        ret = mei_hbm_me_cl_add(dev, (struct hbm_props_response *)req);
        if (ret)
                status = !MEI_HBMS_SUCCESS;

        if (dev->dev_state == MEI_DEV_ENABLED)
                schedule_work(&dev->bus_rescan_work);

        return mei_hbm_add_cl_resp(dev, req->me_addr, status);
}

/**
 * mei_hbm_cl_notify_req - send notification request
 *
 * @dev: the device structure
 * @cl: a client to disconnect from
 * @start: true for start false for stop
 *
 * Return: 0 on success and -EIO on write failure
 */
int mei_hbm_cl_notify_req(struct mei_device *dev,
                          struct mei_cl *cl, u8 start)
{

        struct mei_msg_hdr mei_hdr;
        struct hbm_notification_request req;
        int ret;

        mei_hbm_hdr(&mei_hdr, sizeof(req));
        mei_hbm_cl_hdr(cl, MEI_HBM_NOTIFY_REQ_CMD, &req, sizeof(req));

        req.start = start;

        ret = mei_hbm_write_message(dev, &mei_hdr, &req);
        if (ret)
                cl_err(dev, cl, "notify request failed: ret = %d\n", ret);

        return ret;
}

/**
 *  notify_res_to_fop - convert notification response to the proper
 *      notification FOP
 *
 * @cmd: client notification start response command
 *
 * Return:  MEI_FOP_NOTIFY_START or MEI_FOP_NOTIFY_STOP;
 */
static inline enum mei_cb_file_ops notify_res_to_fop(struct mei_hbm_cl_cmd *cmd)
{
        struct hbm_notification_response *rs =
                (struct hbm_notification_response *)cmd;

        return mei_cl_notify_req2fop(rs->start);
}

/**
 * mei_hbm_cl_notify_start_res - update the client state according
 *       notify start response
 *
 * @dev: the device structure
 * @cl: mei host client
 * @cmd: client notification start response command
 */
static void mei_hbm_cl_notify_start_res(struct mei_device *dev,
                                        struct mei_cl *cl,
                                        struct mei_hbm_cl_cmd *cmd)
{
        struct hbm_notification_response *rs =
                (struct hbm_notification_response *)cmd;

        cl_dbg(dev, cl, "hbm: notify start response status=%d\n", rs->status);

        if (rs->status == MEI_HBMS_SUCCESS ||
            rs->status == MEI_HBMS_ALREADY_STARTED) {
                cl->notify_en = true;
                cl->status = 0;
        } else {
                cl->status = -EINVAL;
        }
}

/**
 * mei_hbm_cl_notify_stop_res - update the client state according
 *       notify stop response
 *
 * @dev: the device structure
 * @cl: mei host client
 * @cmd: client notification stop response command
 */
static void mei_hbm_cl_notify_stop_res(struct mei_device *dev,
                                       struct mei_cl *cl,
                                       struct mei_hbm_cl_cmd *cmd)
{
        struct hbm_notification_response *rs =
                (struct hbm_notification_response *)cmd;

        cl_dbg(dev, cl, "hbm: notify stop response status=%d\n", rs->status);

        if (rs->status == MEI_HBMS_SUCCESS ||
            rs->status == MEI_HBMS_NOT_STARTED) {
                cl->notify_en = false;
                cl->status = 0;
        } else {
                /* TODO: spec is not clear yet about other possible issues */
                cl->status = -EINVAL;
        }
}

/**
 * mei_hbm_cl_notify - signal notification event
 *
 * @dev: the device structure
 * @cmd: notification client message
 */
static void mei_hbm_cl_notify(struct mei_device *dev,
                              struct mei_hbm_cl_cmd *cmd)
{
        struct mei_cl *cl;

        cl = mei_hbm_cl_find_by_cmd(dev, cmd);
        if (cl)
                mei_cl_notify(cl);
}

/**
 * mei_hbm_cl_dma_map_req - send client dma map request
 *
 * @dev: the device structure
 * @cl: mei host client
 *
 * Return: 0 on success and -EIO on write failure
 */
int mei_hbm_cl_dma_map_req(struct mei_device *dev, struct mei_cl *cl)
{
        struct mei_msg_hdr mei_hdr;
        struct hbm_client_dma_map_request req;
        int ret;

        mei_hbm_hdr(&mei_hdr, sizeof(req));

        memset(&req, 0, sizeof(req));

        req.hbm_cmd = MEI_HBM_CLIENT_DMA_MAP_REQ_CMD;
        req.client_buffer_id = cl->dma.buffer_id;
        req.address_lsb = lower_32_bits(cl->dma.daddr);
        req.address_msb = upper_32_bits(cl->dma.daddr);
        req.size = cl->dma.size;

        ret = mei_hbm_write_message(dev, &mei_hdr, &req);
        if (ret)
                cl_err(dev, cl, "dma map request failed: ret = %d\n", ret);

        return ret;
}

/**
 * mei_hbm_cl_dma_unmap_req - send client dma unmap request
 *
 * @dev: the device structure
 * @cl: mei host client
 *
 * Return: 0 on success and -EIO on write failure
 */
int mei_hbm_cl_dma_unmap_req(struct mei_device *dev, struct mei_cl *cl)
{
        struct mei_msg_hdr mei_hdr;
        struct hbm_client_dma_unmap_request req;
        int ret;

        mei_hbm_hdr(&mei_hdr, sizeof(req));

        memset(&req, 0, sizeof(req));

        req.hbm_cmd = MEI_HBM_CLIENT_DMA_UNMAP_REQ_CMD;
        req.client_buffer_id = cl->dma.buffer_id;

        ret = mei_hbm_write_message(dev, &mei_hdr, &req);
        if (ret)
                cl_err(dev, cl, "dma unmap request failed: ret = %d\n", ret);

        return ret;
}

static void mei_hbm_cl_dma_map_res(struct mei_device *dev,
                                   struct hbm_client_dma_response *res)
{
        struct mei_cl *cl;
        struct mei_cl_cb *cb, *next;

        cl = NULL;
        list_for_each_entry_safe(cb, next, &dev->ctrl_rd_list, list) {
                if (cb->fop_type != MEI_FOP_DMA_MAP)
                        continue;
                if (!cb->cl->dma.buffer_id || cb->cl->dma_mapped)
                        continue;

                cl = cb->cl;
                break;
        }
        if (!cl)
                return;

        if (res->status) {
                cl_err(dev, cl, "cl dma map failed %d\n", res->status);
                cl->status = -EFAULT;
        } else {
                cl_dbg(dev, cl, "cl dma map succeeded\n");
                cl->dma_mapped = 1;
                cl->status = 0;
        }
        wake_up(&cl->wait);
}

static void mei_hbm_cl_dma_unmap_res(struct mei_device *dev,
                                     struct hbm_client_dma_response *res)
{
        struct mei_cl *cl;
        struct mei_cl_cb *cb, *next;

        cl = NULL;
        list_for_each_entry_safe(cb, next, &dev->ctrl_rd_list, list) {
                if (cb->fop_type != MEI_FOP_DMA_UNMAP)
                        continue;
                if (!cb->cl->dma.buffer_id || !cb->cl->dma_mapped)
                        continue;

                cl = cb->cl;
                break;
        }
        if (!cl)
                return;

        if (res->status) {
                cl_err(dev, cl, "cl dma unmap failed %d\n", res->status);
                cl->status = -EFAULT;
        } else {
                cl_dbg(dev, cl, "cl dma unmap succeeded\n");
                cl->dma_mapped = 0;
                cl->status = 0;
        }
        wake_up(&cl->wait);
}

/**
 * mei_hbm_prop_req - request property for a single client
 *
 * @dev: the device structure
 * @start_idx: client index to start search
 *
 * Return: 0 on success and < 0 on failure
 */
static int mei_hbm_prop_req(struct mei_device *dev, unsigned long start_idx)
{
        struct mei_msg_hdr mei_hdr;
        struct hbm_props_request req;
        unsigned long addr;
        int ret;

        addr = find_next_bit(dev->me_clients_map, MEI_CLIENTS_MAX, start_idx);

        /* We got all client properties */
        if (addr == MEI_CLIENTS_MAX) {
                dev->hbm_state = MEI_HBM_STARTED;
                mei_host_client_init(dev);
                return 0;
        }

        mei_hbm_hdr(&mei_hdr, sizeof(req));

        memset(&req, 0, sizeof(req));

        req.hbm_cmd = HOST_CLIENT_PROPERTIES_REQ_CMD;
        req.me_addr = addr;

        ret = mei_hbm_write_message(dev, &mei_hdr, &req);
        if (ret) {
                dev_err(&dev->dev, "properties request write failed: ret = %d\n",
                        ret);
                return ret;
        }

        dev->init_clients_timer = dev->timeouts.client_init;
        mei_schedule_stall_timer(dev);

        return 0;
}

/**
 * mei_hbm_pg - sends pg command
 *
 * @dev: the device structure
 * @pg_cmd: the pg command code
 *
 * Return: -EIO on write failure
 *         -EOPNOTSUPP if the operation is not supported by the protocol
 */
int mei_hbm_pg(struct mei_device *dev, u8 pg_cmd)
{
        struct mei_msg_hdr mei_hdr;
        struct hbm_power_gate req;
        int ret;

        if (!dev->hbm_f_pg_supported)
                return -EOPNOTSUPP;

        mei_hbm_hdr(&mei_hdr, sizeof(req));

        memset(&req, 0, sizeof(req));
        req.hbm_cmd = pg_cmd;

        ret = mei_hbm_write_message(dev, &mei_hdr, &req);
        if (ret)
                dev_err(&dev->dev, "power gate command write failed.\n");
        return ret;
}
EXPORT_SYMBOL_GPL(mei_hbm_pg);

/**
 * mei_hbm_stop_req - send stop request message
 *
 * @dev: mei device
 *
 * Return: -EIO on write failure
 */
static int mei_hbm_stop_req(struct mei_device *dev)
{
        struct mei_msg_hdr mei_hdr;
        struct hbm_host_stop_request req;

        mei_hbm_hdr(&mei_hdr, sizeof(req));

        memset(&req, 0, sizeof(req));
        req.hbm_cmd = HOST_STOP_REQ_CMD;
        req.reason = DRIVER_STOP_REQUEST;

        return mei_hbm_write_message(dev, &mei_hdr, &req);
}

/**
 * mei_hbm_cl_flow_control_req - sends flow control request.
 *
 * @dev: the device structure
 * @cl: client info
 *
 * Return: -EIO on write failure
 */
int mei_hbm_cl_flow_control_req(struct mei_device *dev, struct mei_cl *cl)
{
        struct hbm_flow_control req;

        cl_dbg(dev, cl, "sending flow control\n");
        return mei_hbm_cl_write(dev, cl, MEI_FLOW_CONTROL_CMD,
                                &req, sizeof(req));
}

/**
 * mei_hbm_add_single_tx_flow_ctrl_creds - adds single buffer credentials.
 *
 * @dev: the device structure
 * @fctrl: flow control response bus message
 *
 * Return: 0 on success, < 0 otherwise
 */
static int mei_hbm_add_single_tx_flow_ctrl_creds(struct mei_device *dev,
                                                 struct hbm_flow_control *fctrl)
{
        struct mei_me_client *me_cl;
        int rets;

        me_cl = mei_me_cl_by_id(dev, fctrl->me_addr);
        if (!me_cl) {
                dev_err(&dev->dev, "no such me client %d\n", fctrl->me_addr);
                return -ENOENT;
        }

        if (WARN_ON(me_cl->props.single_recv_buf == 0)) {
                rets = -EINVAL;
                goto out;
        }

        me_cl->tx_flow_ctrl_creds++;
        dev_dbg(&dev->dev, "recv flow ctrl msg ME %d (single) creds = %d.\n",
                fctrl->me_addr, me_cl->tx_flow_ctrl_creds);

        rets = 0;
out:
        mei_me_cl_put(me_cl);
        return rets;
}

/**
 * mei_hbm_cl_tx_flow_ctrl_creds_res - flow control response from me
 *
 * @dev: the device structure
 * @fctrl: flow control response bus message
 */
static void mei_hbm_cl_tx_flow_ctrl_creds_res(struct mei_device *dev,
                                               struct hbm_flow_control *fctrl)
{
        struct mei_cl *cl;

        if (!fctrl->host_addr) {
                /* single receive buffer */
                mei_hbm_add_single_tx_flow_ctrl_creds(dev, fctrl);
                return;
        }

        cl = mei_hbm_cl_find_by_cmd(dev, fctrl);
        if (cl) {
                cl->tx_flow_ctrl_creds++;
                cl_dbg(dev, cl, "flow control creds = %d.\n",
                                cl->tx_flow_ctrl_creds);
        }
}


/**
 * mei_hbm_cl_disconnect_req - sends disconnect message to fw.
 *
 * @dev: the device structure
 * @cl: a client to disconnect from
 *
 * Return: -EIO on write failure
 */
int mei_hbm_cl_disconnect_req(struct mei_device *dev, struct mei_cl *cl)
{
        struct hbm_client_connect_request req;

        return mei_hbm_cl_write(dev, cl, CLIENT_DISCONNECT_REQ_CMD,
                                &req, sizeof(req));
}

/**
 * mei_hbm_cl_disconnect_rsp - sends disconnect response to the FW
 *
 * @dev: the device structure
 * @cl: a client to disconnect from
 *
 * Return: -EIO on write failure
 */
int mei_hbm_cl_disconnect_rsp(struct mei_device *dev, struct mei_cl *cl)
{
        struct hbm_client_connect_response resp;

        return mei_hbm_cl_write(dev, cl, CLIENT_DISCONNECT_RES_CMD,
                                &resp, sizeof(resp));
}

/**
 * mei_hbm_cl_disconnect_res - update the client state according
 *       disconnect response
 *
 * @dev: the device structure
 * @cl: mei host client
 * @cmd: disconnect client response host bus message
 */
static void mei_hbm_cl_disconnect_res(struct mei_device *dev, struct mei_cl *cl,
                                      struct mei_hbm_cl_cmd *cmd)
{
        struct hbm_client_connect_response *rs =
                (struct hbm_client_connect_response *)cmd;

        cl_dbg(dev, cl, "hbm: disconnect response status=%d\n", rs->status);

        if (rs->status == MEI_CL_DISCONN_SUCCESS)
                cl->state = MEI_FILE_DISCONNECT_REPLY;
        cl->status = 0;
}

/**
 * mei_hbm_cl_connect_req - send connection request to specific me client
 *
 * @dev: the device structure
 * @cl: a client to connect to
 *
 * Return: -EIO on write failure
 */
int mei_hbm_cl_connect_req(struct mei_device *dev, struct mei_cl *cl)
{
        struct hbm_client_connect_request req;

        return mei_hbm_cl_write(dev, cl, CLIENT_CONNECT_REQ_CMD,
                                &req, sizeof(req));
}

/**
 * mei_hbm_cl_connect_res - update the client state according
 *        connection response
 *
 * @dev: the device structure
 * @cl: mei host client
 * @cmd: connect client response host bus message
 */
static void mei_hbm_cl_connect_res(struct mei_device *dev, struct mei_cl *cl,
                                   struct mei_hbm_cl_cmd *cmd)
{
        struct hbm_client_connect_response *rs =
                (struct hbm_client_connect_response *)cmd;

        cl_dbg(dev, cl, "hbm: connect response status=%s\n",
                        mei_cl_conn_status_str(rs->status));

        if (rs->status == MEI_CL_CONN_SUCCESS)
                cl->state = MEI_FILE_CONNECTED;
        else {
                cl->state = MEI_FILE_DISCONNECT_REPLY;
                if (rs->status == MEI_CL_CONN_NOT_FOUND) {
                        mei_me_cl_del(dev, cl->me_cl);
                        if (dev->dev_state == MEI_DEV_ENABLED)
                                schedule_work(&dev->bus_rescan_work);
                }
        }
        cl->status = mei_cl_conn_status_to_errno(rs->status);
}

/**
 * mei_hbm_cl_res - process hbm response received on behalf
 *         an client
 *
 * @dev: the device structure
 * @rs:  hbm client message
 * @fop_type: file operation type
 */
static void mei_hbm_cl_res(struct mei_device *dev,
                           struct mei_hbm_cl_cmd *rs,
                           enum mei_cb_file_ops fop_type)
{
        struct mei_cl *cl;
        struct mei_cl_cb *cb, *next;

        cl = NULL;
        list_for_each_entry_safe(cb, next, &dev->ctrl_rd_list, list) {

                cl = cb->cl;

                if (cb->fop_type != fop_type)
                        continue;

                if (mei_hbm_cl_addr_equal(cl, rs)) {
                        list_del_init(&cb->list);
                        break;
                }
        }

        if (!cl)
                return;

        switch (fop_type) {
        case MEI_FOP_CONNECT:
                mei_hbm_cl_connect_res(dev, cl, rs);
                break;
        case MEI_FOP_DISCONNECT:
                mei_hbm_cl_disconnect_res(dev, cl, rs);
                break;
        case MEI_FOP_NOTIFY_START:
                mei_hbm_cl_notify_start_res(dev, cl, rs);
                break;
        case MEI_FOP_NOTIFY_STOP:
                mei_hbm_cl_notify_stop_res(dev, cl, rs);
                break;
        default:
                return;
        }

        cl->timer_count = 0;
        wake_up(&cl->wait);
}


/**
 * mei_hbm_fw_disconnect_req - disconnect request initiated by ME firmware
 *  host sends disconnect response
 *
 * @dev: the device structure.
 * @disconnect_req: disconnect request bus message from the me
 *
 * Return: -ENOMEM on allocation failure
 */
static int mei_hbm_fw_disconnect_req(struct mei_device *dev,
                struct hbm_client_connect_request *disconnect_req)
{
        struct mei_cl *cl;
        struct mei_cl_cb *cb;

        cl = mei_hbm_cl_find_by_cmd(dev, disconnect_req);
        if (cl) {
                cl_warn(dev, cl, "fw disconnect request received\n");
                cl->state = MEI_FILE_DISCONNECTING;
                cl->timer_count = 0;

                cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, MEI_FOP_DISCONNECT_RSP,
                                               NULL);
                if (!cb)
                        return -ENOMEM;
        }
        return 0;
}

/**
 * mei_hbm_pg_enter_res - PG enter response received
 *
 * @dev: the device structure.
 *
 * Return: 0 on success, -EPROTO on state mismatch
 */
static int mei_hbm_pg_enter_res(struct mei_device *dev)
{
        if (mei_pg_state(dev) != MEI_PG_OFF ||
            dev->pg_event != MEI_PG_EVENT_WAIT) {
                dev_err(&dev->dev, "hbm: pg entry response: state mismatch [%s, %d]\n",
                        mei_pg_state_str(mei_pg_state(dev)), dev->pg_event);
                return -EPROTO;
        }

        dev->pg_event = MEI_PG_EVENT_RECEIVED;
        wake_up(&dev->wait_pg);

        return 0;
}

/**
 * mei_hbm_pg_resume - process with PG resume
 *
 * @dev: the device structure.
 */
void mei_hbm_pg_resume(struct mei_device *dev)
{
        pm_request_resume(dev->parent);
}
EXPORT_SYMBOL_GPL(mei_hbm_pg_resume);

/**
 * mei_hbm_pg_exit_res - PG exit response received
 *
 * @dev: the device structure.
 *
 * Return: 0 on success, -EPROTO on state mismatch
 */
static int mei_hbm_pg_exit_res(struct mei_device *dev)
{
        if (mei_pg_state(dev) != MEI_PG_ON ||
            (dev->pg_event != MEI_PG_EVENT_WAIT &&
             dev->pg_event != MEI_PG_EVENT_IDLE)) {
                dev_err(&dev->dev, "hbm: pg exit response: state mismatch [%s, %d]\n",
                        mei_pg_state_str(mei_pg_state(dev)), dev->pg_event);
                return -EPROTO;
        }

        switch (dev->pg_event) {
        case MEI_PG_EVENT_WAIT:
                dev->pg_event = MEI_PG_EVENT_RECEIVED;
                wake_up(&dev->wait_pg);
                break;
        case MEI_PG_EVENT_IDLE:
                /*
                * If the driver is not waiting on this then
                * this is HW initiated exit from PG.
                * Start runtime pm resume sequence to exit from PG.
                */
                dev->pg_event = MEI_PG_EVENT_RECEIVED;
                mei_hbm_pg_resume(dev);
                break;
        default:
                WARN(1, "hbm: pg exit response: unexpected pg event = %d\n",
                     dev->pg_event);
                return -EPROTO;
        }

        return 0;
}

/**
 * mei_hbm_config_features - check what hbm features and commands
 *        are supported by the fw
 *
 * @dev: the device structure
 */
static void mei_hbm_config_features(struct mei_device *dev)
{
        /* Power Gating Isolation Support */
        dev->hbm_f_pg_supported = 0;
        if (dev->version.major_version > HBM_MAJOR_VERSION_PGI)
                dev->hbm_f_pg_supported = 1;

        if (dev->version.major_version == HBM_MAJOR_VERSION_PGI &&
            dev->version.minor_version >= HBM_MINOR_VERSION_PGI)
                dev->hbm_f_pg_supported = 1;

        dev->hbm_f_dc_supported = 0;
        if (dev->version.major_version >= HBM_MAJOR_VERSION_DC)
                dev->hbm_f_dc_supported = 1;

        dev->hbm_f_ie_supported = 0;
        if (dev->version.major_version >= HBM_MAJOR_VERSION_IE)
                dev->hbm_f_ie_supported = 1;

        /* disconnect on connect timeout instead of link reset */
        dev->hbm_f_dot_supported = 0;
        if (dev->version.major_version >= HBM_MAJOR_VERSION_DOT)
                dev->hbm_f_dot_supported = 1;

        /* Notification Event Support */
        dev->hbm_f_ev_supported = 0;
        if (dev->version.major_version >= HBM_MAJOR_VERSION_EV)
                dev->hbm_f_ev_supported = 1;

        /* Fixed Address Client Support */
        dev->hbm_f_fa_supported = 0;
        if (dev->version.major_version >= HBM_MAJOR_VERSION_FA)
                dev->hbm_f_fa_supported = 1;

        /* OS ver message Support */
        dev->hbm_f_os_supported = 0;
        if (dev->version.major_version >= HBM_MAJOR_VERSION_OS)
                dev->hbm_f_os_supported = 1;

        /* DMA Ring Support */
        dev->hbm_f_dr_supported = 0;
        if (dev->version.major_version > HBM_MAJOR_VERSION_DR ||
            (dev->version.major_version == HBM_MAJOR_VERSION_DR &&
             dev->version.minor_version >= HBM_MINOR_VERSION_DR))
                dev->hbm_f_dr_supported = 1;

        /* VTag Support */
        dev->hbm_f_vt_supported = 0;
        if (dev->version.major_version > HBM_MAJOR_VERSION_VT ||
            (dev->version.major_version == HBM_MAJOR_VERSION_VT &&
             dev->version.minor_version >= HBM_MINOR_VERSION_VT))
                dev->hbm_f_vt_supported = 1;

        /* GSC support */
        if (dev->version.major_version > HBM_MAJOR_VERSION_GSC ||
            (dev->version.major_version == HBM_MAJOR_VERSION_GSC &&
             dev->version.minor_version >= HBM_MINOR_VERSION_GSC))
                dev->hbm_f_gsc_supported = 1;

        /* Capability message Support */
        dev->hbm_f_cap_supported = 0;
        if (dev->version.major_version > HBM_MAJOR_VERSION_CAP ||
            (dev->version.major_version == HBM_MAJOR_VERSION_CAP &&
             dev->version.minor_version >= HBM_MINOR_VERSION_CAP))
                dev->hbm_f_cap_supported = 1;

        /* Client DMA Support */
        dev->hbm_f_cd_supported = 0;
        if (dev->version.major_version > HBM_MAJOR_VERSION_CD ||
            (dev->version.major_version == HBM_MAJOR_VERSION_CD &&
             dev->version.minor_version >= HBM_MINOR_VERSION_CD))
                dev->hbm_f_cd_supported = 1;
}

/**
 * mei_hbm_version_is_supported - checks whether the driver can
 *     support the hbm version of the device
 *
 * @dev: the device structure
 * Return: true if driver can support hbm version of the device
 */
bool mei_hbm_version_is_supported(struct mei_device *dev)
{
        return  (dev->version.major_version < HBM_MAJOR_VERSION) ||
                (dev->version.major_version == HBM_MAJOR_VERSION &&
                 dev->version.minor_version <= HBM_MINOR_VERSION);
}

/**
 * mei_hbm_dispatch - bottom half read routine after ISR to
 * handle the read bus message cmd processing.
 *
 * @dev: the device structure
 * @hdr: header of bus message
 *
 * Return: 0 on success and < 0 on failure
 */
int mei_hbm_dispatch(struct mei_device *dev, struct mei_msg_hdr *hdr)
{
        struct mei_bus_message *mei_msg;
        struct hbm_host_version_response *version_res;
        struct hbm_props_response *props_res;
        struct hbm_host_enum_response *enum_res;
        struct hbm_dma_setup_response *dma_setup_res;
        struct hbm_add_client_request *add_cl_req;
        struct hbm_capability_response *capability_res;
        int ret;

        struct mei_hbm_cl_cmd *cl_cmd;
        struct hbm_client_connect_request *disconnect_req;
        struct hbm_flow_control *fctrl;
        struct hbm_client_dma_response *client_dma_res;

        /* read the message to our buffer */
        BUG_ON(hdr->length >= sizeof(dev->rd_msg_buf));
        mei_read_slots(dev, dev->rd_msg_buf, hdr->length);
        mei_msg = (struct mei_bus_message *)dev->rd_msg_buf;
        cl_cmd  = (struct mei_hbm_cl_cmd *)mei_msg;

        /* ignore spurious message and prevent reset nesting
         * hbm is put to idle during system reset
         */
        if (dev->hbm_state == MEI_HBM_IDLE) {
                dev_dbg(&dev->dev, "hbm: state is idle ignore spurious messages\n");
                return 0;
        }

        switch (mei_msg->hbm_cmd) {
        case HOST_START_RES_CMD:
                dev_dbg(&dev->dev, "hbm: start: response message received.\n");

                dev->init_clients_timer = 0;

                version_res = (struct hbm_host_version_response *)mei_msg;

                dev_dbg(&dev->dev, "HBM VERSION: DRIVER=%02d:%02d DEVICE=%02d:%02d\n",
                                HBM_MAJOR_VERSION, HBM_MINOR_VERSION,
                                version_res->me_max_version.major_version,
                                version_res->me_max_version.minor_version);

                if (version_res->host_version_supported) {
                        dev->version.major_version = HBM_MAJOR_VERSION;
                        dev->version.minor_version = HBM_MINOR_VERSION;
                } else {
                        dev->version.major_version =
                                version_res->me_max_version.major_version;
                        dev->version.minor_version =
                                version_res->me_max_version.minor_version;
                }

                if (!mei_hbm_version_is_supported(dev)) {
                        dev_warn(&dev->dev, "hbm: start: version mismatch - stopping the driver.\n");

                        dev->hbm_state = MEI_HBM_STOPPED;
                        if (mei_hbm_stop_req(dev)) {
                                dev_err(&dev->dev, "hbm: start: failed to send stop request\n");
                                return -EIO;
                        }
                        break;
                }

                mei_hbm_config_features(dev);

                if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
                    dev->hbm_state != MEI_HBM_STARTING) {
                        if (dev->dev_state == MEI_DEV_POWER_DOWN ||
                            dev->dev_state == MEI_DEV_POWERING_DOWN) {
                                dev_dbg(&dev->dev, "hbm: start: on shutdown, ignoring\n");
                                return 0;
                        }
                        dev_err(&dev->dev, "hbm: start: state mismatch, [%d, %d]\n",
                                dev->dev_state, dev->hbm_state);
                        return -EPROTO;
                }

                if (dev->hbm_f_cap_supported) {
                        if (mei_hbm_capabilities_req(dev))
                                return -EIO;
                        wake_up(&dev->wait_hbm_start);
                        break;
                }

                if (dev->hbm_f_dr_supported) {
                        if (mei_dmam_ring_alloc(dev))
                                dev_info(&dev->dev, "running w/o dma ring\n");
                        if (mei_dma_ring_is_allocated(dev)) {
                                if (mei_hbm_dma_setup_req(dev))
                                        return -EIO;

                                wake_up(&dev->wait_hbm_start);
                                break;
                        }
                }

                dev->hbm_f_dr_supported = 0;
                mei_dmam_ring_free(dev);

                if (mei_hbm_enum_clients_req(dev))
                        return -EIO;

                wake_up(&dev->wait_hbm_start);
                break;

        case MEI_HBM_CAPABILITIES_RES_CMD:
                dev_dbg(&dev->dev, "hbm: capabilities response: message received.\n");

                dev->init_clients_timer = 0;

                if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
                    dev->hbm_state != MEI_HBM_CAP_SETUP) {
                        if (dev->dev_state == MEI_DEV_POWER_DOWN ||
                            dev->dev_state == MEI_DEV_POWERING_DOWN) {
                                dev_dbg(&dev->dev, "hbm: capabilities response: on shutdown, ignoring\n");
                                return 0;
                        }
                        dev_err(&dev->dev, "hbm: capabilities response: state mismatch, [%d, %d]\n",
                                dev->dev_state, dev->hbm_state);
                        return -EPROTO;
                }

                capability_res = (struct hbm_capability_response *)mei_msg;
                if (!(capability_res->capability_granted[0] & HBM_CAP_VT))
                        dev->hbm_f_vt_supported = 0;
                if (!(capability_res->capability_granted[0] & HBM_CAP_CD))
                        dev->hbm_f_cd_supported = 0;

                if (!(capability_res->capability_granted[0] & HBM_CAP_GSC))
                        dev->hbm_f_gsc_supported = 0;

                if (dev->hbm_f_dr_supported) {
                        if (mei_dmam_ring_alloc(dev))
                                dev_info(&dev->dev, "running w/o dma ring\n");
                        if (mei_dma_ring_is_allocated(dev)) {
                                if (mei_hbm_dma_setup_req(dev))
                                        return -EIO;
                                break;
                        }
                }

                dev->hbm_f_dr_supported = 0;
                mei_dmam_ring_free(dev);

                if (mei_hbm_enum_clients_req(dev))
                        return -EIO;
                break;

        case MEI_HBM_DMA_SETUP_RES_CMD:
                dev_dbg(&dev->dev, "hbm: dma setup response: message received.\n");

                dev->init_clients_timer = 0;

                if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
                    dev->hbm_state != MEI_HBM_DR_SETUP) {
                        if (dev->dev_state == MEI_DEV_POWER_DOWN ||
                            dev->dev_state == MEI_DEV_POWERING_DOWN) {
                                dev_dbg(&dev->dev, "hbm: dma setup response: on shutdown, ignoring\n");
                                return 0;
                        }
                        dev_err(&dev->dev, "hbm: dma setup response: state mismatch, [%d, %d]\n",
                                dev->dev_state, dev->hbm_state);
                        return -EPROTO;
                }

                dma_setup_res = (struct hbm_dma_setup_response *)mei_msg;

                if (dma_setup_res->status) {
                        u8 status = dma_setup_res->status;

                        if (status == MEI_HBMS_NOT_ALLOWED) {
                                dev_dbg(&dev->dev, "hbm: dma setup not allowed\n");
                        } else {
                                dev_info(&dev->dev, "hbm: dma setup response: failure = %d %s\n",
                                         status,
                                         mei_hbm_status_str(status));
                        }
                        dev->hbm_f_dr_supported = 0;
                        mei_dmam_ring_free(dev);
                }

                if (mei_hbm_enum_clients_req(dev))
                        return -EIO;
                break;

        case CLIENT_CONNECT_RES_CMD:
                dev_dbg(&dev->dev, "hbm: client connect response: message received.\n");
                mei_hbm_cl_res(dev, cl_cmd, MEI_FOP_CONNECT);
                break;

        case CLIENT_DISCONNECT_RES_CMD:
                dev_dbg(&dev->dev, "hbm: client disconnect response: message received.\n");
                mei_hbm_cl_res(dev, cl_cmd, MEI_FOP_DISCONNECT);
                break;

        case MEI_FLOW_CONTROL_CMD:
                dev_dbg(&dev->dev, "hbm: client flow control response: message received.\n");

                fctrl = (struct hbm_flow_control *)mei_msg;
                mei_hbm_cl_tx_flow_ctrl_creds_res(dev, fctrl);
                break;

        case MEI_PG_ISOLATION_ENTRY_RES_CMD:
                dev_dbg(&dev->dev, "hbm: power gate isolation entry response received\n");
                ret = mei_hbm_pg_enter_res(dev);
                if (ret)
                        return ret;
                break;

        case MEI_PG_ISOLATION_EXIT_REQ_CMD:
                dev_dbg(&dev->dev, "hbm: power gate isolation exit request received\n");
                ret = mei_hbm_pg_exit_res(dev);
                if (ret)
                        return ret;
                break;

        case HOST_CLIENT_PROPERTIES_RES_CMD:
                dev_dbg(&dev->dev, "hbm: properties response: message received.\n");

                dev->init_clients_timer = 0;

                if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
                    dev->hbm_state != MEI_HBM_CLIENT_PROPERTIES) {
                        if (dev->dev_state == MEI_DEV_POWER_DOWN ||
                            dev->dev_state == MEI_DEV_POWERING_DOWN) {
                                dev_dbg(&dev->dev, "hbm: properties response: on shutdown, ignoring\n");
                                return 0;
                        }
                        dev_err(&dev->dev, "hbm: properties response: state mismatch, [%d, %d]\n",
                                dev->dev_state, dev->hbm_state);
                        return -EPROTO;
                }

                props_res = (struct hbm_props_response *)mei_msg;

                if (props_res->status == MEI_HBMS_CLIENT_NOT_FOUND) {
                        dev_dbg(&dev->dev, "hbm: properties response: %d CLIENT_NOT_FOUND\n",
                                props_res->me_addr);
                } else if (props_res->status) {
                        dev_err(&dev->dev, "hbm: properties response: wrong status = %d %s\n",
                                props_res->status,
                                mei_hbm_status_str(props_res->status));
                        return -EPROTO;
                } else {
                        mei_hbm_me_cl_add(dev, props_res);
                }

                /* request property for the next client */
                if (mei_hbm_prop_req(dev, props_res->me_addr + 1))
                        return -EIO;

                break;

        case HOST_ENUM_RES_CMD:
                dev_dbg(&dev->dev, "hbm: enumeration response: message received\n");

                dev->init_clients_timer = 0;

                enum_res = (struct hbm_host_enum_response *) mei_msg;
                BUILD_BUG_ON(sizeof(dev->me_clients_map)
                                < sizeof(enum_res->valid_addresses));
                memcpy(dev->me_clients_map, enum_res->valid_addresses,
                                sizeof(enum_res->valid_addresses));

                if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
                    dev->hbm_state != MEI_HBM_ENUM_CLIENTS) {
                        if (dev->dev_state == MEI_DEV_POWER_DOWN ||
                            dev->dev_state == MEI_DEV_POWERING_DOWN) {
                                dev_dbg(&dev->dev, "hbm: enumeration response: on shutdown, ignoring\n");
                                return 0;
                        }
                        dev_err(&dev->dev, "hbm: enumeration response: state mismatch, [%d, %d]\n",
                                dev->dev_state, dev->hbm_state);
                        return -EPROTO;
                }

                dev->hbm_state = MEI_HBM_CLIENT_PROPERTIES;

                /* first property request */
                if (mei_hbm_prop_req(dev, 0))
                        return -EIO;

                break;

        case HOST_STOP_RES_CMD:
                dev_dbg(&dev->dev, "hbm: stop response: message received\n");

                dev->init_clients_timer = 0;

                if (dev->hbm_state != MEI_HBM_STOPPED) {
                        dev_err(&dev->dev, "hbm: stop response: state mismatch, [%d, %d]\n",
                                dev->dev_state, dev->hbm_state);
                        return -EPROTO;
                }

                mei_set_devstate(dev, MEI_DEV_POWER_DOWN);
                dev_info(&dev->dev, "hbm: stop response: resetting.\n");
                /* force the reset */
                return -EPROTO;

        case CLIENT_DISCONNECT_REQ_CMD:
                dev_dbg(&dev->dev, "hbm: disconnect request: message received\n");

                disconnect_req = (struct hbm_client_connect_request *)mei_msg;
                mei_hbm_fw_disconnect_req(dev, disconnect_req);
                break;

        case ME_STOP_REQ_CMD:
                dev_dbg(&dev->dev, "hbm: stop request: message received\n");
                dev->hbm_state = MEI_HBM_STOPPED;
                if (mei_hbm_stop_req(dev)) {
                        dev_err(&dev->dev, "hbm: stop request: failed to send stop request\n");
                        return -EIO;
                }
                break;

        case MEI_HBM_ADD_CLIENT_REQ_CMD:
                dev_dbg(&dev->dev, "hbm: add client request received\n");
                /*
                 * after the host receives the enum_resp
                 * message clients may be added or removed
                 */
                if (dev->hbm_state <= MEI_HBM_ENUM_CLIENTS ||
                    dev->hbm_state >= MEI_HBM_STOPPED) {
                        dev_err(&dev->dev, "hbm: add client: state mismatch, [%d, %d]\n",
                                dev->dev_state, dev->hbm_state);
                        return -EPROTO;
                }
                add_cl_req = (struct hbm_add_client_request *)mei_msg;
                ret = mei_hbm_fw_add_cl_req(dev, add_cl_req);
                if (ret) {
                        dev_err(&dev->dev, "hbm: add client: failed to send response %d\n",
                                ret);
                        return -EIO;
                }
                dev_dbg(&dev->dev, "hbm: add client request processed\n");
                break;

        case MEI_HBM_NOTIFY_RES_CMD:
                dev_dbg(&dev->dev, "hbm: notify response received\n");
                mei_hbm_cl_res(dev, cl_cmd, notify_res_to_fop(cl_cmd));
                break;

        case MEI_HBM_NOTIFICATION_CMD:
                dev_dbg(&dev->dev, "hbm: notification\n");
                mei_hbm_cl_notify(dev, cl_cmd);
                break;

        case MEI_HBM_CLIENT_DMA_MAP_RES_CMD:
                dev_dbg(&dev->dev, "hbm: client dma map response: message received.\n");
                client_dma_res = (struct hbm_client_dma_response *)mei_msg;
                mei_hbm_cl_dma_map_res(dev, client_dma_res);
                break;

        case MEI_HBM_CLIENT_DMA_UNMAP_RES_CMD:
                dev_dbg(&dev->dev, "hbm: client dma unmap response: message received.\n");
                client_dma_res = (struct hbm_client_dma_response *)mei_msg;
                mei_hbm_cl_dma_unmap_res(dev, client_dma_res);
                break;

        default:
                WARN(1, "hbm: wrong command %d\n", mei_msg->hbm_cmd);
                return -EPROTO;

        }
        return 0;
}