staging/mei: MEI driver init flow.

Init driver list and queue, MEI Hardware reset flow,
init of driver specific host client.

MEI Init/reset flow:
- Ack all waiting interrupts
- Hardware reset flow (Set Reset Bit, Generate Interrupt, Clear Reset Bit
  Generate Interrupt)
- Wait for ME Ready Bit (done in interrupt thread)
- Set ME Ready Bit (done in interrupt thread)
- Send Start request (done in interrupt thread)
- wait for answer
- Send Enumerate Clients request (done in interrupt thread)
- wait for answer
- Send Get Client property for each client request (done in interrupt thread)
- Wait for answers
- Init Done.

MEI Driver connect internally to 2 ME clients/features:
AMTHI and AMT watchdog.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Itzhak Tzeel-Krupp <itzhak.tzeel-krupp@intel.com>
Signed-off-by: Oren Weil <oren.jer.weil@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 770 insertions, 0 deletions

diff --git a/drivers/staging/mei/init.c b/drivers/staging/mei/init.c
new file mode 100644
index 00000000000..2818851c076
--- /dev/null
+++ b/drivers/staging/mei/init.c
@@ -0,0 +1,770 @@
+/*
+ *
+ * Intel Management Engine Interface (Intel MEI) Linux driver
+ * Copyright (c) 2003-2011, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, 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 General Public License for
+ * more details.
+ *
+ */
+
+#include <linux/pci.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/delay.h>
+
+#include "mei_dev.h"
+#include "hw.h"
+#include "interface.h"
+#include "mei.h"
+
+const uuid_le mei_amthi_guid  = UUID_LE(0x12f80028, 0xb4b7, 0x4b2d, 0xac,
+                                                0xa8, 0x46, 0xe0, 0xff, 0x65,
+                                                0x81, 0x4c);
+
+/**
+ * mei_initialize_list - Sets up a queue list.
+ *
+ * @list: An instance of our list structure
+ * @dev: the device structure
+ */
+void mei_initialize_list(struct mei_io_list *list, struct mei_device *dev)
+{
+        /* initialize our queue list */
+        INIT_LIST_HEAD(&list->mei_cb.cb_list);
+        list->status = 0;
+        list->device_extension = dev;
+}
+
+/**
+ * mei_flush_queues - flushes queue lists belonging to cl.
+ *
+ * @dev: the device structure
+ * @cl: private data of the file object
+ */
+void mei_flush_queues(struct mei_device *dev, struct mei_cl *cl)
+{
+        int i;
+
+        if (!dev || !cl)
+                return;
+
+        for (i = 0; i < MEI_IO_LISTS_NUMBER; i++) {
+                dev_dbg(&dev->pdev->dev, "remove list entry belonging to cl\n");
+                mei_flush_list(dev->io_list_array[i], cl);
+        }
+}
+
+
+/**
+ * mei_flush_list - removes list entry belonging to cl.
+ *
+ * @list:  An instance of our list structure
+ * @cl: private data of the file object
+ */
+void mei_flush_list(struct mei_io_list *list, struct mei_cl *cl)
+{
+        struct mei_cl *cl_tmp;
+        struct mei_cl_cb *cb_pos = NULL;
+        struct mei_cl_cb *cb_next = NULL;
+
+        if (!list || !cl)
+                return;
+
+        if (list->status != 0)
+                return;
+
+        if (list_empty(&list->mei_cb.cb_list))
+                return;
+
+        list_for_each_entry_safe(cb_pos, cb_next,
+                                 &list->mei_cb.cb_list, cb_list) {
+                if (cb_pos) {
+                        cl_tmp = (struct mei_cl *)
+                                cb_pos->file_private;
+                        if (cl_tmp &&
+                            mei_fe_same_id(cl, cl_tmp))
+                                list_del(&cb_pos->cb_list);
+                }
+        }
+}
+
+/**
+ * mei_reset_iamthif_params - initializes mei device iamthif
+ *
+ * @dev: the device structure
+ */
+static void mei_reset_iamthif_params(struct mei_device *dev)
+{
+        /* reset iamthif parameters. */
+        dev->iamthif_current_cb = NULL;
+        dev->iamthif_msg_buf_size = 0;
+        dev->iamthif_msg_buf_index = 0;
+        dev->iamthif_canceled = 0;
+        dev->iamthif_ioctl = 0;
+        dev->iamthif_state = MEI_IAMTHIF_IDLE;
+        dev->iamthif_timer = 0;
+}
+
+/**
+ * init_mei_device - allocates and initializes the mei device structure
+ *
+ * @pdev: The pci device structure
+ *
+ * returns The mei_device_device pointer on success, NULL on failure.
+ */
+struct mei_device *init_mei_device(struct pci_dev *pdev)
+{
+        int i;
+        struct mei_device *dev;
+
+        dev = kzalloc(sizeof(struct mei_device), GFP_KERNEL);
+        if (!dev)
+                return NULL;
+
+        /* setup our list array */
+        dev->io_list_array[0] = &dev->read_list;
+        dev->io_list_array[1] = &dev->write_list;
+        dev->io_list_array[2] = &dev->write_waiting_list;
+        dev->io_list_array[3] = &dev->ctrl_wr_list;
+        dev->io_list_array[4] = &dev->ctrl_rd_list;
+        dev->io_list_array[5] = &dev->amthi_cmd_list;
+        dev->io_list_array[6] = &dev->amthi_read_complete_list;
+        INIT_LIST_HEAD(&dev->file_list);
+        INIT_LIST_HEAD(&dev->wd_cl.link);
+        INIT_LIST_HEAD(&dev->iamthif_cl.link);
+        mutex_init(&dev->device_lock);
+        init_waitqueue_head(&dev->wait_recvd_msg);
+        init_waitqueue_head(&dev->wait_stop_wd);
+        dev->mei_state = MEI_INITIALIZING;
+        dev->iamthif_state = MEI_IAMTHIF_IDLE;
+        for (i = 0; i < MEI_IO_LISTS_NUMBER; i++)
+                mei_initialize_list(dev->io_list_array[i], dev);
+        dev->pdev = pdev;
+        return dev;
+}
+
+/**
+ * mei_hw_init - initializes host and fw to start work.
+ *
+ * @dev: the device structure
+ *
+ * returns 0 on success, <0 on failure.
+ */
+int mei_hw_init(struct mei_device *dev)
+{
+        int err = 0;
+        int ret;
+
+        mutex_lock(&dev->device_lock);
+
+        dev->host_hw_state = mei_hcsr_read(dev);
+        dev->me_hw_state = mei_mecsr_read(dev);
+        dev_dbg(&dev->pdev->dev, "host_hw_state = 0x%08x, mestate = 0x%08x.\n",
+            dev->host_hw_state, dev->me_hw_state);
+
+        /* acknowledge interrupt and stop interupts */
+        if ((dev->host_hw_state & H_IS) == H_IS)
+                mei_reg_write(dev, H_CSR, dev->host_hw_state);
+
+        dev->recvd_msg = 0;
+        dev_dbg(&dev->pdev->dev, "reset in start the mei device.\n");
+
+        mei_reset(dev, 1);
+
+        dev_dbg(&dev->pdev->dev, "host_hw_state = 0x%08x, me_hw_state = 0x%08x.\n",
+            dev->host_hw_state, dev->me_hw_state);
+
+        /* wait for ME to turn on ME_RDY */
+        if (!dev->recvd_msg) {
+                mutex_unlock(&dev->device_lock);
+                err = wait_event_interruptible_timeout(dev->wait_recvd_msg,
+                        dev->recvd_msg, MEI_INTEROP_TIMEOUT);
+                mutex_lock(&dev->device_lock);
+        }
+
+        if (!err && !dev->recvd_msg) {
+                dev->mei_state = MEI_DISABLED;
+                dev_dbg(&dev->pdev->dev,
+                        "wait_event_interruptible_timeout failed"
+                        "on wait for ME to turn on ME_RDY.\n");
+                ret = -ENODEV;
+                goto out;
+        }
+
+        if (!(((dev->host_hw_state & H_RDY) == H_RDY) &&
+              ((dev->me_hw_state & ME_RDY_HRA) == ME_RDY_HRA))) {
+                dev->mei_state = MEI_DISABLED;
+                dev_dbg(&dev->pdev->dev,
+                        "host_hw_state = 0x%08x, me_hw_state = 0x%08x.\n",
+                        dev->host_hw_state, dev->me_hw_state);
+
+                if (!(dev->host_hw_state & H_RDY) != H_RDY)
+                        dev_dbg(&dev->pdev->dev, "host turn off H_RDY.\n");
+
+                if (!(dev->me_hw_state & ME_RDY_HRA) != ME_RDY_HRA)
+                        dev_dbg(&dev->pdev->dev, "ME turn off ME_RDY.\n");
+
+                printk(KERN_ERR "mei: link layer initialization failed.\n");
+                ret = -ENODEV;
+                goto out;
+        }
+
+        if (dev->version.major_version != HBM_MAJOR_VERSION ||
+            dev->version.minor_version != HBM_MINOR_VERSION) {
+                dev_dbg(&dev->pdev->dev, "MEI start failed.\n");
+                ret = -ENODEV;
+                goto out;
+        }
+
+        dev->recvd_msg = 0;
+        dev_dbg(&dev->pdev->dev, "host_hw_state = 0x%08x, me_hw_state = 0x%08x.\n",
+            dev->host_hw_state, dev->me_hw_state);
+        dev_dbg(&dev->pdev->dev, "ME turn on ME_RDY and host turn on H_RDY.\n");
+        dev_dbg(&dev->pdev->dev, "link layer has been established.\n");
+        dev_dbg(&dev->pdev->dev, "MEI  start success.\n");
+        ret = 0;
+
+out:
+        mutex_unlock(&dev->device_lock);
+        return ret;
+}
+
+/**
+ * mei_hw_reset - resets fw via mei csr register.
+ *
+ * @dev: the device structure
+ * @interrupts_enabled: if interrupt should be enabled after reset.
+ */
+static void mei_hw_reset(struct mei_device *dev, int interrupts_enabled)
+{
+        dev->host_hw_state |= (H_RST | H_IG);
+
+        if (interrupts_enabled)
+                mei_enable_interrupts(dev);
+        else
+                mei_disable_interrupts(dev);
+}
+
+/**
+ * mei_reset - resets host and fw.
+ *
+ * @dev: the device structure
+ * @interrupts_enabled: if interrupt should be enabled after reset.
+ */
+void mei_reset(struct mei_device *dev, int interrupts_enabled)
+{
+        struct mei_cl *cl_pos = NULL;
+        struct mei_cl *cl_next = NULL;
+        struct mei_cl_cb *cb_pos = NULL;
+        struct mei_cl_cb *cb_next = NULL;
+        bool unexpected;
+
+        if (dev->mei_state == MEI_RECOVERING_FROM_RESET) {
+                dev->need_reset = 1;
+                return;
+        }
+
+        unexpected = (dev->mei_state != MEI_INITIALIZING &&
+                        dev->mei_state != MEI_DISABLED &&
+                        dev->mei_state != MEI_POWER_DOWN &&
+                        dev->mei_state != MEI_POWER_UP);
+
+        dev->host_hw_state = mei_hcsr_read(dev);
+
+        dev_dbg(&dev->pdev->dev, "before reset host_hw_state = 0x%08x.\n",
+            dev->host_hw_state);
+
+        mei_hw_reset(dev, interrupts_enabled);
+
+        dev->host_hw_state &= ~H_RST;
+        dev->host_hw_state |= H_IG;
+
+        mei_hcsr_set(dev);
+
+        dev_dbg(&dev->pdev->dev, "currently saved host_hw_state = 0x%08x.\n",
+            dev->host_hw_state);
+
+        dev->need_reset = 0;
+
+        if (dev->mei_state != MEI_INITIALIZING) {
+                if (dev->mei_state != MEI_DISABLED &&
+                    dev->mei_state != MEI_POWER_DOWN)
+                        dev->mei_state = MEI_RESETING;
+
+                list_for_each_entry_safe(cl_pos,
+                                cl_next, &dev->file_list, link) {
+                        cl_pos->state = MEI_FILE_DISCONNECTED;
+                        cl_pos->mei_flow_ctrl_creds = 0;
+                        cl_pos->read_cb = NULL;
+                        cl_pos->timer_count = 0;
+                }
+                /* remove entry if already in list */
+                dev_dbg(&dev->pdev->dev, "list del iamthif and wd file list.\n");
+                mei_remove_client_from_file_list(dev,
+                                dev->wd_cl.host_client_id);
+
+                mei_remove_client_from_file_list(dev,
+                                dev->iamthif_cl.host_client_id);
+
+                mei_reset_iamthif_params(dev);
+                dev->wd_due_counter = 0;
+                dev->extra_write_index = 0;
+        }
+
+        dev->num_mei_me_clients = 0;
+        dev->rd_msg_hdr = 0;
+        dev->stop = 0;
+        dev->wd_pending = 0;
+
+        /* update the state of the registers after reset */
+        dev->host_hw_state = mei_hcsr_read(dev);
+        dev->me_hw_state = mei_mecsr_read(dev);
+
+        dev_dbg(&dev->pdev->dev, "after reset host_hw_state = 0x%08x, me_hw_state = 0x%08x.\n",
+            dev->host_hw_state, dev->me_hw_state);
+
+        if (unexpected)
+                dev_warn(&dev->pdev->dev, "unexpected reset.\n");
+
+        /* Wake up all readings so they can be interrupted */
+        list_for_each_entry_safe(cl_pos, cl_next, &dev->file_list, link) {
+                if (waitqueue_active(&cl_pos->rx_wait)) {
+                        dev_dbg(&dev->pdev->dev, "Waking up client!\n");
+                        wake_up_interruptible(&cl_pos->rx_wait);
+                }
+        }
+        /* remove all waiting requests */
+        if (dev->write_list.status == 0 &&
+                !list_empty(&dev->write_list.mei_cb.cb_list)) {
+                list_for_each_entry_safe(cb_pos, cb_next,
+                                &dev->write_list.mei_cb.cb_list, cb_list) {
+                        if (cb_pos) {
+                                list_del(&cb_pos->cb_list);
+                                mei_free_cb_private(cb_pos);
+                                cb_pos = NULL;
+                        }
+                }
+        }
+}
+
+
+
+/**
+ * host_start_message - mei host sends start message.
+ *
+ * @dev: the device structure
+ *
+ * returns none.
+ */
+void host_start_message(struct mei_device *dev)
+{
+        struct mei_msg_hdr *mei_hdr;
+        struct hbm_host_version_request *host_start_req;
+
+        /* host start message */
+        mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
+        mei_hdr->host_addr = 0;
+        mei_hdr->me_addr = 0;
+        mei_hdr->length = sizeof(struct hbm_host_version_request);
+        mei_hdr->msg_complete = 1;
+        mei_hdr->reserved = 0;
+
+        host_start_req =
+            (struct hbm_host_version_request *) &dev->wr_msg_buf[1];
+        memset(host_start_req, 0, sizeof(struct hbm_host_version_request));
+        host_start_req->cmd.cmd = HOST_START_REQ_CMD;
+        host_start_req->host_version.major_version = HBM_MAJOR_VERSION;
+        host_start_req->host_version.minor_version = HBM_MINOR_VERSION;
+        dev->recvd_msg = 0;
+        if (!mei_write_message(dev, mei_hdr,
+                                       (unsigned char *) (host_start_req),
+                                       mei_hdr->length)) {
+                dev_dbg(&dev->pdev->dev, "write send version message to FW fail.\n");
+                dev->mei_state = MEI_RESETING;
+                mei_reset(dev, 1);
+        }
+        dev->init_clients_state = MEI_START_MESSAGE;
+        dev->init_clients_timer = INIT_CLIENTS_TIMEOUT;
+        return ;
+}
+
+/**
+ * host_enum_clients_message - host sends enumeration client request message.
+ *
+ * @dev: the device structure
+ *
+ * returns none.
+ */
+void host_enum_clients_message(struct mei_device *dev)
+{
+        struct mei_msg_hdr *mei_hdr;
+        struct hbm_host_enum_request *host_enum_req;
+        mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
+        /* enumerate clients */
+        mei_hdr->host_addr = 0;
+        mei_hdr->me_addr = 0;
+        mei_hdr->length = sizeof(struct hbm_host_enum_request);
+        mei_hdr->msg_complete = 1;
+        mei_hdr->reserved = 0;
+
+        host_enum_req = (struct hbm_host_enum_request *) &dev->wr_msg_buf[1];
+        memset(host_enum_req, 0, sizeof(struct hbm_host_enum_request));
+        host_enum_req->cmd.cmd = HOST_ENUM_REQ_CMD;
+        if (!mei_write_message(dev, mei_hdr,
+                               (unsigned char *) (host_enum_req),
+                                mei_hdr->length)) {
+                dev->mei_state = MEI_RESETING;
+                dev_dbg(&dev->pdev->dev, "write send enumeration request message to FW fail.\n");
+                mei_reset(dev, 1);
+        }
+        dev->init_clients_state = MEI_ENUM_CLIENTS_MESSAGE;
+        dev->init_clients_timer = INIT_CLIENTS_TIMEOUT;
+        return ;
+}
+
+
+/**
+ * allocate_me_clients_storage - allocates storage for me clients
+ *
+ * @dev: the device structure
+ *
+ * returns none.
+ */
+void allocate_me_clients_storage(struct mei_device *dev)
+{
+        struct mei_me_client *clients;
+        int b;
+
+        /* count how many ME clients we have */
+        for_each_set_bit(b, dev->me_clients_map, MEI_CLIENTS_MAX)
+                dev->num_mei_me_clients++;
+
+        if (dev->num_mei_me_clients <= 0)
+                return ;
+
+
+        if (dev->me_clients != NULL) {
+                kfree(dev->me_clients);
+                dev->me_clients = NULL;
+        }
+        dev_dbg(&dev->pdev->dev, "memory allocation for ME clients size=%zd.\n",
+                dev->num_mei_me_clients * sizeof(struct mei_me_client));
+        /* allocate storage for ME clients representation */
+        clients = kcalloc(dev->num_mei_me_clients,
+                        sizeof(struct mei_me_client), GFP_KERNEL);
+        if (!clients) {
+                dev_dbg(&dev->pdev->dev, "memory allocation for ME clients failed.\n");
+                dev->mei_state = MEI_RESETING;
+                mei_reset(dev, 1);
+                return ;
+        }
+        dev->me_clients = clients;
+        return ;
+}
+/**
+ * host_client_properties - reads properties for client
+ *
+ * @dev: the device structure
+ *
+ * returns none.
+ */
+void host_client_properties(struct mei_device *dev)
+{
+        struct mei_msg_hdr *mei_header;
+        struct hbm_props_request *host_cli_req;
+        int b;
+        u8 client_num = dev->me_client_presentation_num;
+
+        b = dev->me_client_index;
+        b = find_next_bit(dev->me_clients_map, MEI_CLIENTS_MAX, b);
+        if (b < MEI_CLIENTS_MAX) {
+                dev->me_clients[client_num].client_id = b;
+                dev->me_clients[client_num].mei_flow_ctrl_creds = 0;
+                mei_header = (struct mei_msg_hdr *)&dev->wr_msg_buf[0];
+                mei_header->host_addr = 0;
+                mei_header->me_addr = 0;
+                mei_header->length = sizeof(struct hbm_props_request);
+                mei_header->msg_complete = 1;
+                mei_header->reserved = 0;
+
+                host_cli_req = (struct hbm_props_request *)&dev->wr_msg_buf[1];
+
+                memset(host_cli_req, 0, sizeof(struct hbm_props_request));
+
+                host_cli_req->cmd.cmd = HOST_CLIENT_PROPERTIES_REQ_CMD;
+                host_cli_req->address = b;
+
+                if (!mei_write_message(dev, mei_header,
+                                (unsigned char *)host_cli_req,
+                                mei_header->length)) {
+                        dev->mei_state = MEI_RESETING;
+                        dev_dbg(&dev->pdev->dev, "write send enumeration request message to FW fail.\n");
+                        mei_reset(dev, 1);
+                        return;
+                }
+
+                dev->init_clients_timer = INIT_CLIENTS_TIMEOUT;
+                dev->me_client_index = b;
+                return;
+        }
+
+
+        /*
+         * Clear Map for indicating now ME clients
+         * with associated host client
+         */
+        bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
+        dev->write_hang = -1;
+        dev->open_handle_count = 0;
+        bitmap_set(dev->host_clients_map, 0, 3);
+        dev->mei_state = MEI_ENABLED;
+
+        mei_wd_host_init(dev);
+        return;
+}
+
+/**
+ * mei_init_file_private - initializes private file structure.
+ *
+ * @priv: private file structure to be initialized
+ * @file: the file structure
+ */
+void mei_init_file_private(struct mei_cl *priv, struct mei_device *dev)
+{
+        memset(priv, 0, sizeof(struct mei_cl));
+        init_waitqueue_head(&priv->wait);
+        init_waitqueue_head(&priv->rx_wait);
+        init_waitqueue_head(&priv->tx_wait);
+        INIT_LIST_HEAD(&priv->link);
+        priv->reading_state = MEI_IDLE;
+        priv->writing_state = MEI_IDLE;
+        priv->dev = dev;
+}
+
+int mei_find_me_client_index(const struct mei_device *dev, uuid_le cuuid)
+{
+        int i, res = -1;
+
+        for (i = 0; i < dev->num_mei_me_clients; ++i)
+                if (uuid_le_cmp(cuuid,
+                                dev->me_clients[i].props.protocol_name) == 0) {
+                        res = i;
+                        break;
+                }
+
+        return res;
+}
+
+
+/**
+ * mei_find_me_client_update_filext - searches for ME client guid
+ *                       sets client_id in mei_file_private if found
+ * @dev: the device structure
+ * @priv: private file structure to set client_id in
+ * @cguid: searched guid of ME client
+ * @client_id: id of host client to be set in file private structure
+ *
+ * returns ME client index
+ */
+u8 mei_find_me_client_update_filext(struct mei_device *dev, struct mei_cl *priv,
+                                const uuid_le *cguid, u8 client_id)
+{
+        int i;
+
+        if (!dev || !priv || !cguid)
+                return 0;
+
+        /* check for valid client id */
+        i = mei_find_me_client_index(dev, *cguid);
+        if (i >= 0) {
+                priv->me_client_id = dev->me_clients[i].client_id;
+                priv->state = MEI_FILE_CONNECTING;
+                priv->host_client_id = client_id;
+
+                list_add_tail(&priv->link, &dev->file_list);
+                return (u8)i;
+        }
+
+        return 0;
+}
+
+/**
+ * host_init_iamthif - mei initialization iamthif client.
+ *
+ * @dev: the device structure
+ *
+ */
+void host_init_iamthif(struct mei_device *dev)
+{
+        u8 i;
+        unsigned char *msg_buf;
+
+        mei_init_file_private(&dev->iamthif_cl, dev);
+        dev->iamthif_cl.state = MEI_FILE_DISCONNECTED;
+
+        /* find ME amthi client */
+        i = mei_find_me_client_update_filext(dev, &dev->iamthif_cl,
+                            &mei_amthi_guid, MEI_IAMTHIF_HOST_CLIENT_ID);
+        if (dev->iamthif_cl.state != MEI_FILE_CONNECTING) {
+                dev_dbg(&dev->pdev->dev, "failed to find iamthif client.\n");
+                return;
+        }
+
+        /* Do not render the system unusable when iamthif_mtu is not equal to
+        the value received from ME.
+        Assign iamthif_mtu to the value received from ME in order to solve the
+        hardware macro incompatibility. */
+
+        dev_dbg(&dev->pdev->dev, "[DEFAULT] IAMTHIF = %d\n", dev->iamthif_mtu);
+        dev->iamthif_mtu = dev->me_clients[i].props.max_msg_length;
+        dev_dbg(&dev->pdev->dev,
+                        "IAMTHIF = %d\n",
+                        dev->me_clients[i].props.max_msg_length);
+
+        kfree(dev->iamthif_msg_buf);
+        dev->iamthif_msg_buf = NULL;
+
+        /* allocate storage for ME message buffer */
+        msg_buf = kcalloc(dev->iamthif_mtu,
+                        sizeof(unsigned char), GFP_KERNEL);
+        if (!msg_buf) {
+                dev_dbg(&dev->pdev->dev, "memory allocation for ME message buffer failed.\n");
+                return;
+        }
+
+        dev->iamthif_msg_buf = msg_buf;
+
+        if (!mei_connect(dev, &dev->iamthif_cl)) {
+                dev_dbg(&dev->pdev->dev, "Failed to connect to AMTHI client\n");
+                dev->iamthif_cl.state = MEI_FILE_DISCONNECTED;
+                dev->iamthif_cl.host_client_id = 0;
+        } else {
+                dev->iamthif_cl.timer_count = CONNECT_TIMEOUT;
+        }
+}
+
+/**
+ * mei_alloc_file_private - allocates a private file structure and sets it up.
+ * @file: the file structure
+ *
+ * returns  The allocated file or NULL on failure
+ */
+struct mei_cl *mei_alloc_file_private(struct mei_device *dev)
+{
+        struct mei_cl *priv;
+
+        priv = kmalloc(sizeof(struct mei_cl), GFP_KERNEL);
+        if (!priv)
+                return NULL;
+
+        mei_init_file_private(priv, dev);
+
+        return priv;
+}
+
+
+
+/**
+ * mei_disconnect_host_client - sends disconnect message to fw from host client.
+ *
+ * @dev: the device structure
+ * @cl: private data of the file object
+ *
+ * Locking: called under "dev->device_lock" lock
+ *
+ * returns 0 on success, <0 on failure.
+ */
+int mei_disconnect_host_client(struct mei_device *dev, struct mei_cl *cl)
+{
+        int rets, err;
+        long timeout = 15;      /* 15 seconds */
+        struct mei_cl_cb *cb;
+
+        if (!dev || !cl)
+                return -ENODEV;
+
+        if (cl->state != MEI_FILE_DISCONNECTING)
+                return 0;
+
+        cb = kzalloc(sizeof(struct mei_cl_cb), GFP_KERNEL);
+        if (!cb)
+                return -ENOMEM;
+
+        INIT_LIST_HEAD(&cb->cb_list);
+        cb->file_private = cl;
+        cb->major_file_operations = MEI_CLOSE;
+        if (dev->mei_host_buffer_is_empty) {
+                dev->mei_host_buffer_is_empty = 0;
+                if (mei_disconnect(dev, cl)) {
+                        mdelay(10); /* Wait for hardware disconnection ready */
+                        list_add_tail(&cb->cb_list,
+                                &dev->ctrl_rd_list.mei_cb.cb_list);
+                } else {
+                        rets = -ENODEV;
+                        dev_dbg(&dev->pdev->dev, "failed to call mei_disconnect.\n");
+                        goto free;
+                }
+        } else {
+                dev_dbg(&dev->pdev->dev, "add disconnect cb to control write list\n");
+                list_add_tail(&cb->cb_list,
+                                &dev->ctrl_wr_list.mei_cb.cb_list);
+        }
+        mutex_unlock(&dev->device_lock);
+
+        err = wait_event_timeout(dev->wait_recvd_msg,
+                 (MEI_FILE_DISCONNECTED == cl->state),
+                 timeout * HZ);
+
+        mutex_lock(&dev->device_lock);
+        if (MEI_FILE_DISCONNECTED == cl->state) {
+                rets = 0;
+                dev_dbg(&dev->pdev->dev, "successfully disconnected from FW client.\n");
+        } else {
+                rets = -ENODEV;
+                if (MEI_FILE_DISCONNECTED != cl->state)
+                        dev_dbg(&dev->pdev->dev, "wrong status client disconnect.\n");
+
+                if (err)
+                        dev_dbg(&dev->pdev->dev,
+                                        "wait failed disconnect err=%08x\n",
+                                        err);
+
+                dev_dbg(&dev->pdev->dev, "failed to disconnect from FW client.\n");
+        }
+
+        mei_flush_list(&dev->ctrl_rd_list, cl);
+        mei_flush_list(&dev->ctrl_wr_list, cl);
+free:
+        mei_free_cb_private(cb);
+        return rets;
+}
+
+/**
+ * mei_remove_client_from_file_list -
+ *      removes file private data from device file list
+ *
+ * @dev: the device structure
+ * @host_client_id: host client id to be removed
+ */
+void mei_remove_client_from_file_list(struct mei_device *dev,
+                                       u8 host_client_id)
+{
+        struct mei_cl *cl_pos = NULL;
+        struct mei_cl *cl_next = NULL;
+        list_for_each_entry_safe(cl_pos, cl_next, &dev->file_list, link) {
+                if (host_client_id == cl_pos->host_client_id) {
+                        dev_dbg(&dev->pdev->dev, "remove host client = %d, ME client = %d\n",
+                                        cl_pos->host_client_id,
+                                        cl_pos->me_client_id);
+                        list_del_init(&cl_pos->link);
+                        break;
+                }
+        }
+}