Merge tag 'char-misc-3.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

Pull Char/Misc driver merge from Greg Kroah-Hartman:
 "Here is the "big" char/misc driver patches for 3.8-rc1.  I'm starting
  to put random driver subsystems that I had previously sent you through
  the driver-core tree in this tree, as it makes more sense to do so.

  Nothing major here, the various __dev* removals, some mei driver
  updates, and other random driver-specific things from the different
  maintainers and developers.

  Note, some MFD drivers got added through this tree, and they are also
  coming in through the "real" MFD tree as well, due to some major
  mis-communication between me and the different developers.  If you
  have any merge conflicts, take the ones from the MFD tree, not these
  ones, sorry about that.

  All of this has been in linux-next for a while.

  Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>"

Fix up trivial conflict in drivers/mmc/host/Kconfig due to new drivers
having been added (both at the end, as usual..)

* tag 'char-misc-3.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (84 commits)
  MAINTAINERS: remove drivers/staging/hv/
  misc/st_kim: Free resources in the error path of probe()
  drivers/char: for hpet, add count checking, and ~0UL instead of -1
  w1-gpio: Simplify & get rid of defines
  w1-gpio: Pinctrl-fy
  extcon: remove use of __devexit_p
  extcon: remove use of __devinit
  extcon: remove use of __devexit
  drivers: uio: Only allocate new private data when probing device tree node
  drivers: uio_dmem_genirq: Allow partial success when opening device
  drivers: uio_dmem_genirq: Don't use DMA_ERROR_CODE to indicate unmapped regions
  drivers: uio_dmem_genirq: Don't mix address spaces for dynamic region vaddr
  uio: remove use of __devexit
  uio: remove use of __devinitdata
  uio: remove use of __devinit
  uio: remove use of __devexit_p
  char: remove use of __devexit
  char: remove use of __devinitconst
  char: remove use of __devinitdata
  char: remove use of __devinit
  ...

10 files changed, 1531 insertions, 1534 deletions

diff --git a/drivers/misc/mei/Makefile b/drivers/misc/mei/Makefile
index 57168db6c7e5..0017842e166c 100644
--- a/drivers/misc/mei/Makefile
+++ b/drivers/misc/mei/Makefile
@@ -8,4 +8,5 @@ mei-objs += interrupt.o
 mei-objs += interface.o
 mei-objs += iorw.o
 mei-objs += main.o
+mei-objs += amthif.o
 mei-objs += wd.o
diff --git a/drivers/misc/mei/amthif.c b/drivers/misc/mei/amthif.c
new file mode 100644
index 000000000000..18794aea6062
--- /dev/null
+++ b/drivers/misc/mei/amthif.c
@@ -0,0 +1,722 @@
+/*
+ *
+ * Intel Management Engine Interface (Intel MEI) Linux driver
+ * Copyright (c) 2003-2012, 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/kernel.h>
+#include <linux/fs.h>
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/fcntl.h>
+#include <linux/aio.h>
+#include <linux/pci.h>
+#include <linux/init.h>
+#include <linux/ioctl.h>
+#include <linux/cdev.h>
+#include <linux/list.h>
+#include <linux/delay.h>
+#include <linux/sched.h>
+#include <linux/uuid.h>
+#include <linux/jiffies.h>
+#include <linux/uaccess.h>
+
+
+#include "mei_dev.h"
+#include "hw.h"
+#include <linux/mei.h>
+#include "interface.h"
+
+const uuid_le mei_amthi_guid  = UUID_LE(0x12f80028, 0xb4b7, 0x4b2d, 0xac,
+						0xa8, 0x46, 0xe0, 0xff, 0x65,
+						0x81, 0x4c);
+
+/**
+ * mei_amthif_reset_params - initializes mei device iamthif
+ *
+ * @dev: the device structure
+ */
+void mei_amthif_reset_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 = false;
+	dev->iamthif_ioctl = false;
+	dev->iamthif_state = MEI_IAMTHIF_IDLE;
+	dev->iamthif_timer = 0;
+}
+
+/**
+ * mei_amthif_host_init_ - mei initialization amthif client.
+ *
+ * @dev: the device structure
+ *
+ */
+void mei_amthif_host_init(struct mei_device *dev)
+{
+	int i;
+	unsigned char *msg_buf;
+
+	mei_cl_init(&dev->iamthif_cl, dev);
+	dev->iamthif_cl.state = MEI_FILE_DISCONNECTED;
+
+	/* find ME amthi client */
+	i = mei_me_cl_link(dev, &dev->iamthif_cl,
+			    &mei_amthi_guid, MEI_IAMTHIF_HOST_CLIENT_ID);
+	if (i < 0) {
+		dev_info(&dev->pdev->dev, "failed to find iamthif client.\n");
+		return;
+	}
+
+	/* Assign iamthif_mtu to the value received from ME  */
+
+	dev->iamthif_mtu = dev->me_clients[i].props.max_msg_length;
+	dev_dbg(&dev->pdev->dev, "IAMTHIF_MTU = %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 = MEI_CONNECT_TIMEOUT;
+	}
+}
+
+/**
+ * mei_amthif_find_read_list_entry - finds a amthilist entry for current file
+ *
+ * @dev: the device structure
+ * @file: pointer to file object
+ *
+ * returns   returned a list entry on success, NULL on failure.
+ */
+struct mei_cl_cb *mei_amthif_find_read_list_entry(struct mei_device *dev,
+						struct file *file)
+{
+	struct mei_cl_cb *pos = NULL;
+	struct mei_cl_cb *next = NULL;
+
+	list_for_each_entry_safe(pos, next,
+				&dev->amthif_rd_complete_list.list, list) {
+		if (pos->cl && pos->cl == &dev->iamthif_cl &&
+			pos->file_object == file)
+			return pos;
+	}
+	return NULL;
+}
+
+
+/**
+ * mei_amthif_read - read data from AMTHIF client
+ *
+ * @dev: the device structure
+ * @if_num:  minor number
+ * @file: pointer to file object
+ * @*ubuf: pointer to user data in user space
+ * @length: data length to read
+ * @offset: data read offset
+ *
+ * Locking: called under "dev->device_lock" lock
+ *
+ * returns
+ *  returned data length on success,
+ *  zero if no data to read,
+ *  negative on failure.
+ */
+int mei_amthif_read(struct mei_device *dev, struct file *file,
+	       char __user *ubuf, size_t length, loff_t *offset)
+{
+	int rets;
+	int wait_ret;
+	struct mei_cl_cb *cb = NULL;
+	struct mei_cl *cl = file->private_data;
+	unsigned long timeout;
+	int i;
+
+	/* Only Posible if we are in timeout */
+	if (!cl || cl != &dev->iamthif_cl) {
+		dev_dbg(&dev->pdev->dev, "bad file ext.\n");
+		return -ETIMEDOUT;
+	}
+
+	i = mei_me_cl_by_id(dev, dev->iamthif_cl.me_client_id);
+
+	if (i < 0) {
+		dev_dbg(&dev->pdev->dev, "amthi client not found.\n");
+		return -ENODEV;
+	}
+	dev_dbg(&dev->pdev->dev, "checking amthi data\n");
+	cb = mei_amthif_find_read_list_entry(dev, file);
+
+	/* Check for if we can block or not*/
+	if (cb == NULL && file->f_flags & O_NONBLOCK)
+		return -EAGAIN;
+
+
+	dev_dbg(&dev->pdev->dev, "waiting for amthi data\n");
+	while (cb == NULL) {
+		/* unlock the Mutex */
+		mutex_unlock(&dev->device_lock);
+
+		wait_ret = wait_event_interruptible(dev->iamthif_cl.wait,
+			(cb = mei_amthif_find_read_list_entry(dev, file)));
+
+		if (wait_ret)
+			return -ERESTARTSYS;
+
+		dev_dbg(&dev->pdev->dev, "woke up from sleep\n");
+
+		/* Locking again the Mutex */
+		mutex_lock(&dev->device_lock);
+	}
+
+
+	dev_dbg(&dev->pdev->dev, "Got amthi data\n");
+	dev->iamthif_timer = 0;
+
+	if (cb) {
+		timeout = cb->read_time +
+			mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
+		dev_dbg(&dev->pdev->dev, "amthi timeout = %lud\n",
+				timeout);
+
+		if  (time_after(jiffies, timeout)) {
+			dev_dbg(&dev->pdev->dev, "amthi Time out\n");
+			/* 15 sec for the message has expired */
+			list_del(&cb->list);
+			rets = -ETIMEDOUT;
+			goto free;
+		}
+	}
+	/* if the whole message will fit remove it from the list */
+	if (cb->buf_idx >= *offset && length >= (cb->buf_idx - *offset))
+		list_del(&cb->list);
+	else if (cb->buf_idx > 0 && cb->buf_idx <= *offset) {
+		/* end of the message has been reached */
+		list_del(&cb->list);
+		rets = 0;
+		goto free;
+	}
+		/* else means that not full buffer will be read and do not
+		 * remove message from deletion list
+		 */
+
+	dev_dbg(&dev->pdev->dev, "amthi cb->response_buffer size - %d\n",
+	    cb->response_buffer.size);
+	dev_dbg(&dev->pdev->dev, "amthi cb->buf_idx - %lu\n", cb->buf_idx);
+
+	/* length is being turncated to PAGE_SIZE, however,
+	 * the buf_idx may point beyond */
+	length = min_t(size_t, length, (cb->buf_idx - *offset));
+
+	if (copy_to_user(ubuf, cb->response_buffer.data + *offset, length))
+		rets = -EFAULT;
+	else {
+		rets = length;
+		if ((*offset + length) < cb->buf_idx) {
+			*offset += length;
+			goto out;
+		}
+	}
+free:
+	dev_dbg(&dev->pdev->dev, "free amthi cb memory.\n");
+	*offset = 0;
+	mei_io_cb_free(cb);
+out:
+	return rets;
+}
+
+/**
+ * mei_amthif_send_cmd - send amthif command to the ME
+ *
+ * @dev: the device structure
+ * @cb: mei call back struct
+ *
+ * returns 0 on success, <0 on failure.
+ *
+ */
+static int mei_amthif_send_cmd(struct mei_device *dev, struct mei_cl_cb *cb)
+{
+	struct mei_msg_hdr mei_hdr;
+	int ret;
+
+	if (!dev || !cb)
+		return -ENODEV;
+
+	dev_dbg(&dev->pdev->dev, "write data to amthi client.\n");
+
+	dev->iamthif_state = MEI_IAMTHIF_WRITING;
+	dev->iamthif_current_cb = cb;
+	dev->iamthif_file_object = cb->file_object;
+	dev->iamthif_canceled = false;
+	dev->iamthif_ioctl = true;
+	dev->iamthif_msg_buf_size = cb->request_buffer.size;
+	memcpy(dev->iamthif_msg_buf, cb->request_buffer.data,
+	       cb->request_buffer.size);
+
+	ret = mei_flow_ctrl_creds(dev, &dev->iamthif_cl);
+	if (ret < 0)
+		return ret;
+
+	if (ret && dev->mei_host_buffer_is_empty) {
+		ret = 0;
+		dev->mei_host_buffer_is_empty = false;
+		if (cb->request_buffer.size > mei_hbuf_max_data(dev)) {
+			mei_hdr.length = mei_hbuf_max_data(dev);
+			mei_hdr.msg_complete = 0;
+		} else {
+			mei_hdr.length = cb->request_buffer.size;
+			mei_hdr.msg_complete = 1;
+		}
+
+		mei_hdr.host_addr = dev->iamthif_cl.host_client_id;
+		mei_hdr.me_addr = dev->iamthif_cl.me_client_id;
+		mei_hdr.reserved = 0;
+		dev->iamthif_msg_buf_index += mei_hdr.length;
+		if (mei_write_message(dev, &mei_hdr,
+					(unsigned char *)(dev->iamthif_msg_buf),
+					mei_hdr.length))
+			return -ENODEV;
+
+		if (mei_hdr.msg_complete) {
+			if (mei_flow_ctrl_reduce(dev, &dev->iamthif_cl))
+				return -ENODEV;
+			dev->iamthif_flow_control_pending = true;
+			dev->iamthif_state = MEI_IAMTHIF_FLOW_CONTROL;
+			dev_dbg(&dev->pdev->dev, "add amthi cb to write waiting list\n");
+			dev->iamthif_current_cb = cb;
+			dev->iamthif_file_object = cb->file_object;
+			list_add_tail(&cb->list, &dev->write_waiting_list.list);
+		} else {
+			dev_dbg(&dev->pdev->dev, "message does not complete, so add amthi cb to write list.\n");
+			list_add_tail(&cb->list, &dev->write_list.list);
+		}
+	} else {
+		if (!(dev->mei_host_buffer_is_empty))
+			dev_dbg(&dev->pdev->dev, "host buffer is not empty");
+
+		dev_dbg(&dev->pdev->dev, "No flow control credentials, so add iamthif cb to write list.\n");
+		list_add_tail(&cb->list, &dev->write_list.list);
+	}
+	return 0;
+}
+
+/**
+ * mei_amthif_write - write amthif data to amthif client
+ *
+ * @dev: the device structure
+ * @cb: mei call back struct
+ *
+ * returns 0 on success, <0 on failure.
+ *
+ */
+int mei_amthif_write(struct mei_device *dev, struct mei_cl_cb *cb)
+{
+	int ret;
+
+	if (!dev || !cb)
+		return -ENODEV;
+
+	ret = mei_io_cb_alloc_resp_buf(cb, dev->iamthif_mtu);
+	if (ret)
+		return ret;
+
+	cb->fop_type = MEI_FOP_IOCTL;
+
+	if (!list_empty(&dev->amthif_cmd_list.list) ||
+	    dev->iamthif_state != MEI_IAMTHIF_IDLE) {
+		dev_dbg(&dev->pdev->dev,
+			"amthif state = %d\n", dev->iamthif_state);
+		dev_dbg(&dev->pdev->dev, "AMTHIF: add cb to the wait list\n");
+		list_add_tail(&cb->list, &dev->amthif_cmd_list.list);
+		return 0;
+	}
+	return mei_amthif_send_cmd(dev, cb);
+}
+/**
+ * mei_amthif_run_next_cmd
+ *
+ * @dev: the device structure
+ *
+ * returns 0 on success, <0 on failure.
+ */
+void mei_amthif_run_next_cmd(struct mei_device *dev)
+{
+	struct mei_cl_cb *pos = NULL;
+	struct mei_cl_cb *next = NULL;
+	int status;
+
+	if (!dev)
+		return;
+
+	dev->iamthif_msg_buf_size = 0;
+	dev->iamthif_msg_buf_index = 0;
+	dev->iamthif_canceled = false;
+	dev->iamthif_ioctl = true;
+	dev->iamthif_state = MEI_IAMTHIF_IDLE;
+	dev->iamthif_timer = 0;
+	dev->iamthif_file_object = NULL;
+
+	dev_dbg(&dev->pdev->dev, "complete amthi cmd_list cb.\n");
+
+	list_for_each_entry_safe(pos, next, &dev->amthif_cmd_list.list, list) {
+		list_del(&pos->list);
+
+		if (pos->cl && pos->cl == &dev->iamthif_cl) {
+			status = mei_amthif_send_cmd(dev, pos);
+			if (status) {
+				dev_dbg(&dev->pdev->dev,
+					"amthi write failed status = %d\n",
+						status);
+				return;
+			}
+			break;
+		}
+	}
+}
+
+
+unsigned int mei_amthif_poll(struct mei_device *dev,
+		struct file *file, poll_table *wait)
+{
+	unsigned int mask = 0;
+	mutex_unlock(&dev->device_lock);
+	poll_wait(file, &dev->iamthif_cl.wait, wait);
+	mutex_lock(&dev->device_lock);
+	if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE &&
+		dev->iamthif_file_object == file) {
+		mask |= (POLLIN | POLLRDNORM);
+		dev_dbg(&dev->pdev->dev, "run next amthi cb\n");
+		mei_amthif_run_next_cmd(dev);
+	}
+	return mask;
+}
+
+
+
+/**
+ * mei_amthif_irq_process_completed - processes completed iamthif operation.
+ *
+ * @dev: the device structure.
+ * @slots: free slots.
+ * @cb_pos: callback block.
+ * @cl: private data of the file object.
+ * @cmpl_list: complete list.
+ *
+ * returns 0, OK; otherwise, error.
+ */
+int mei_amthif_irq_write_complete(struct mei_device *dev, s32 *slots,
+			struct mei_cl_cb *cb, struct mei_cl_cb *cmpl_list)
+{
+	struct mei_msg_hdr *mei_hdr;
+	struct mei_cl *cl = cb->cl;
+	size_t len = dev->iamthif_msg_buf_size - dev->iamthif_msg_buf_index;
+	size_t msg_slots = mei_data2slots(len);
+
+	mei_hdr = (struct mei_msg_hdr *)&dev->wr_msg_buf[0];
+	mei_hdr->host_addr = cl->host_client_id;
+	mei_hdr->me_addr = cl->me_client_id;
+	mei_hdr->reserved = 0;
+
+	if (*slots >= msg_slots) {
+		mei_hdr->length = len;
+		mei_hdr->msg_complete = 1;
+	/* Split the message only if we can write the whole host buffer */
+	} else if (*slots == dev->hbuf_depth) {
+		msg_slots = *slots;
+		len = (*slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
+		mei_hdr->length = len;
+		mei_hdr->msg_complete = 0;
+	} else {
+		/* wait for next time the host buffer is empty */
+		return 0;
+	}
+
+	dev_dbg(&dev->pdev->dev, "msg: len = %d complete = %d\n",
+			mei_hdr->length, mei_hdr->msg_complete);
+
+	*slots -=  msg_slots;
+	if (mei_write_message(dev, mei_hdr,
+		dev->iamthif_msg_buf + dev->iamthif_msg_buf_index,
+		mei_hdr->length)) {
+			dev->iamthif_state = MEI_IAMTHIF_IDLE;
+			cl->status = -ENODEV;
+			list_del(&cb->list);
+			return -ENODEV;
+	}
+
+	if (mei_flow_ctrl_reduce(dev, cl))
+		return -ENODEV;
+
+	dev->iamthif_msg_buf_index += mei_hdr->length;
+	cl->status = 0;
+
+	if (mei_hdr->msg_complete) {
+		dev->iamthif_state = MEI_IAMTHIF_FLOW_CONTROL;
+		dev->iamthif_flow_control_pending = true;
+
+		/* save iamthif cb sent to amthi client */
+		cb->buf_idx = dev->iamthif_msg_buf_index;
+		dev->iamthif_current_cb = cb;
+
+		list_move_tail(&cb->list, &dev->write_waiting_list.list);
+	}
+
+
+	return 0;
+}
+
+/**
+ * mei_amthif_irq_read_message - read routine after ISR to
+ *			handle the read amthi message
+ *
+ * @complete_list: An instance of our list structure
+ * @dev: the device structure
+ * @mei_hdr: header of amthi message
+ *
+ * returns 0 on success, <0 on failure.
+ */
+int mei_amthif_irq_read_message(struct mei_cl_cb *complete_list,
+		struct mei_device *dev, struct mei_msg_hdr *mei_hdr)
+{
+	struct mei_cl_cb *cb;
+	unsigned char *buffer;
+
+	BUG_ON(mei_hdr->me_addr != dev->iamthif_cl.me_client_id);
+	BUG_ON(dev->iamthif_state != MEI_IAMTHIF_READING);
+
+	buffer = dev->iamthif_msg_buf + dev->iamthif_msg_buf_index;
+	BUG_ON(dev->iamthif_mtu < dev->iamthif_msg_buf_index + mei_hdr->length);
+
+	mei_read_slots(dev, buffer, mei_hdr->length);
+
+	dev->iamthif_msg_buf_index += mei_hdr->length;
+
+	if (!mei_hdr->msg_complete)
+		return 0;
+
+	dev_dbg(&dev->pdev->dev,
+			"amthi_message_buffer_index =%d\n",
+			mei_hdr->length);
+
+	dev_dbg(&dev->pdev->dev, "completed amthi read.\n ");
+	if (!dev->iamthif_current_cb)
+		return -ENODEV;
+
+	cb = dev->iamthif_current_cb;
+	dev->iamthif_current_cb = NULL;
+
+	if (!cb->cl)
+		return -ENODEV;
+
+	dev->iamthif_stall_timer = 0;
+	cb->buf_idx = dev->iamthif_msg_buf_index;
+	cb->read_time = jiffies;
+	if (dev->iamthif_ioctl && cb->cl == &dev->iamthif_cl) {
+		/* found the iamthif cb */
+		dev_dbg(&dev->pdev->dev, "complete the amthi read cb.\n ");
+		dev_dbg(&dev->pdev->dev, "add the amthi read cb to complete.\n ");
+		list_add_tail(&cb->list, &complete_list->list);
+	}
+	return 0;
+}
+
+/**
+ * mei_amthif_irq_read - prepares to read amthif data.
+ *
+ * @dev: the device structure.
+ * @slots: free slots.
+ *
+ * returns 0, OK; otherwise, error.
+ */
+int mei_amthif_irq_read(struct mei_device *dev, s32 *slots)
+{
+
+	if (((*slots) * sizeof(u32)) < (sizeof(struct mei_msg_hdr)
+			+ sizeof(struct hbm_flow_control))) {
+		return -EMSGSIZE;
+	}
+	*slots -= mei_data2slots(sizeof(struct hbm_flow_control));
+	if (mei_send_flow_control(dev, &dev->iamthif_cl)) {
+		dev_dbg(&dev->pdev->dev, "iamthif flow control failed\n");
+		return -EIO;
+	}
+
+	dev_dbg(&dev->pdev->dev, "iamthif flow control success\n");
+	dev->iamthif_state = MEI_IAMTHIF_READING;
+	dev->iamthif_flow_control_pending = false;
+	dev->iamthif_msg_buf_index = 0;
+	dev->iamthif_msg_buf_size = 0;
+	dev->iamthif_stall_timer = MEI_IAMTHIF_STALL_TIMER;
+	dev->mei_host_buffer_is_empty = mei_hbuf_is_empty(dev);
+	return 0;
+}
+
+/**
+ * mei_amthif_complete - complete amthif callback.
+ *
+ * @dev: the device structure.
+ * @cb_pos: callback block.
+ */
+void mei_amthif_complete(struct mei_device *dev, struct mei_cl_cb *cb)
+{
+	if (dev->iamthif_canceled != 1) {
+		dev->iamthif_state = MEI_IAMTHIF_READ_COMPLETE;
+		dev->iamthif_stall_timer = 0;
+		memcpy(cb->response_buffer.data,
+				dev->iamthif_msg_buf,
+				dev->iamthif_msg_buf_index);
+		list_add_tail(&cb->list, &dev->amthif_rd_complete_list.list);
+		dev_dbg(&dev->pdev->dev, "amthi read completed\n");
+		dev->iamthif_timer = jiffies;
+		dev_dbg(&dev->pdev->dev, "dev->iamthif_timer = %ld\n",
+				dev->iamthif_timer);
+	} else {
+		mei_amthif_run_next_cmd(dev);
+	}
+
+	dev_dbg(&dev->pdev->dev, "completing amthi call back.\n");
+	wake_up_interruptible(&dev->iamthif_cl.wait);
+}
+
+/**
+ * mei_clear_list - removes all callbacks associated with file
+ *		from mei_cb_list
+ *
+ * @dev: device structure.
+ * @file: file structure
+ * @mei_cb_list: callbacks list
+ *
+ * mei_clear_list is called to clear resources associated with file
+ * when application calls close function or Ctrl-C was pressed
+ *
+ * returns true if callback removed from the list, false otherwise
+ */
+static bool mei_clear_list(struct mei_device *dev,
+		const struct file *file, struct list_head *mei_cb_list)
+{
+	struct mei_cl_cb *cb_pos = NULL;
+	struct mei_cl_cb *cb_next = NULL;
+	bool removed = false;
+
+	/* list all list member */
+	list_for_each_entry_safe(cb_pos, cb_next, mei_cb_list, list) {
+		/* check if list member associated with a file */
+		if (file == cb_pos->file_object) {
+			/* remove member from the list */
+			list_del(&cb_pos->list);
+			/* check if cb equal to current iamthif cb */
+			if (dev->iamthif_current_cb == cb_pos) {
+				dev->iamthif_current_cb = NULL;
+				/* send flow control to iamthif client */
+				mei_send_flow_control(dev, &dev->iamthif_cl);
+			}
+			/* free all allocated buffers */
+			mei_io_cb_free(cb_pos);
+			cb_pos = NULL;
+			removed = true;
+		}
+	}
+	return removed;
+}
+
+/**
+ * mei_clear_lists - removes all callbacks associated with file
+ *
+ * @dev: device structure
+ * @file: file structure
+ *
+ * mei_clear_lists is called to clear resources associated with file
+ * when application calls close function or Ctrl-C was pressed
+ *
+ * returns true if callback removed from the list, false otherwise
+ */
+static bool mei_clear_lists(struct mei_device *dev, struct file *file)
+{
+	bool removed = false;
+
+	/* remove callbacks associated with a file */
+	mei_clear_list(dev, file, &dev->amthif_cmd_list.list);
+	if (mei_clear_list(dev, file, &dev->amthif_rd_complete_list.list))
+		removed = true;
+
+	mei_clear_list(dev, file, &dev->ctrl_rd_list.list);
+
+	if (mei_clear_list(dev, file, &dev->ctrl_wr_list.list))
+		removed = true;
+
+	if (mei_clear_list(dev, file, &dev->write_waiting_list.list))
+		removed = true;
+
+	if (mei_clear_list(dev, file, &dev->write_list.list))
+		removed = true;
+
+	/* check if iamthif_current_cb not NULL */
+	if (dev->iamthif_current_cb && !removed) {
+		/* check file and iamthif current cb association */
+		if (dev->iamthif_current_cb->file_object == file) {
+			/* remove cb */
+			mei_io_cb_free(dev->iamthif_current_cb);
+			dev->iamthif_current_cb = NULL;
+			removed = true;
+		}
+	}
+	return removed;
+}
+
+/**
+* mei_amthif_release - the release function
+*
+*  @inode: pointer to inode structure
+*  @file: pointer to file structure
+*
+*  returns 0 on success, <0 on error
+*/
+int mei_amthif_release(struct mei_device *dev, struct file *file)
+{
+	if (dev->open_handle_count > 0)
+		dev->open_handle_count--;
+
+	if (dev->iamthif_file_object == file &&
+	    dev->iamthif_state != MEI_IAMTHIF_IDLE) {
+
+		dev_dbg(&dev->pdev->dev, "amthi canceled iamthif state %d\n",
+		    dev->iamthif_state);
+		dev->iamthif_canceled = true;
+		if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE) {
+			dev_dbg(&dev->pdev->dev, "run next amthi iamthif cb\n");
+			mei_amthif_run_next_cmd(dev);
+		}
+	}
+
+	if (mei_clear_lists(dev, file))
+		dev->iamthif_state = MEI_IAMTHIF_IDLE;
+
+	return 0;
+}
diff --git a/drivers/misc/mei/hw.h b/drivers/misc/mei/hw.h
index 9700532f02f6..be8ca6b333ca 100644
--- a/drivers/misc/mei/hw.h
+++ b/drivers/misc/mei/hw.h
@@ -20,16 +20,16 @@
 #include <linux/uuid.h>
 
 /*
- * Timeouts
+ * Timeouts in Seconds
  */
-#define MEI_INTEROP_TIMEOUT    (HZ * 7)
-#define MEI_CONNECT_TIMEOUT		3	/* at least 2 seconds */
+#define MEI_INTEROP_TIMEOUT         7  /* Timeout on ready message */
+#define MEI_CONNECT_TIMEOUT         3  /* HPS: at least 2 seconds */
 
-#define CONNECT_TIMEOUT        15	/* HPS definition */
-#define INIT_CLIENTS_TIMEOUT   15	/* HPS definition */
+#define MEI_CL_CONNECT_TIMEOUT     15  /* HPS: Client Connect Timeout */
+#define MEI_CLIENTS_INIT_TIMEOUT   15  /* HPS: Clients Enumeration Timeout */
 
-#define IAMTHIF_STALL_TIMER		12	/* seconds */
-#define IAMTHIF_READ_TIMER		10000	/* ms */
+#define MEI_IAMTHIF_STALL_TIMER    12  /* HPS */
+#define MEI_IAMTHIF_READ_TIMER     10  /* HPS */
 
 /*
  * Internal Clients Number
@@ -293,6 +293,14 @@ struct hbm_props_response {
 	struct mei_client_properties client_properties;
 } __packed;
 
+/**
+ * struct hbm_client_connect_request - connect/disconnect request
+ *
+ * @hbm_cmd - bus message command header
+ * @me_addr - address of the client in ME
+ * @host_addr - address of the client in the driver
+ * @reserved
+ */
 struct hbm_client_connect_request {
 	u8 hbm_cmd;
 	u8 me_addr;
@@ -300,6 +308,14 @@ struct hbm_client_connect_request {
 	u8 reserved;
 } __packed;
 
+/**
+ * struct hbm_client_connect_response - connect/disconnect response
+ *
+ * @hbm_cmd - bus message command header
+ * @me_addr - address of the client in ME
+ * @host_addr - address of the client in the driver
+ * @status - status of the request
+ */
 struct hbm_client_connect_response {
 	u8 hbm_cmd;
 	u8 me_addr;
@@ -307,12 +323,6 @@ struct hbm_client_connect_response {
 	u8 status;
 } __packed;
 
-struct hbm_client_disconnect_request {
-	u8 hbm_cmd;
-	u8 me_addr;
-	u8 host_addr;
-	u8 reserved[1];
-} __packed;
 
 #define MEI_FC_MESSAGE_RESERVED_LENGTH           5
 
diff --git a/drivers/misc/mei/init.c b/drivers/misc/mei/init.c
index 98f1430e3e14..a54cd5567ca2 100644
--- a/drivers/misc/mei/init.c
+++ b/drivers/misc/mei/init.c
@@ -43,21 +43,6 @@ const char *mei_dev_state_str(int state)
 }
 
 
-const uuid_le mei_amthi_guid  = UUID_LE(0x12f80028, 0xb4b7, 0x4b2d, 0xac,
-						0xa8, 0x46, 0xe0, 0xff, 0x65,
-						0x81, 0x4c);
-
-/**
- * mei_io_list_init - Sets up a queue list.
- *
- * @list: An instance io list structure
- * @dev: the device structure
- */
-void mei_io_list_init(struct mei_io_list *list)
-{
-	/* initialize our queue list */
-	INIT_LIST_HEAD(&list->mei_cb.cb_list);
-}
 
 /**
  * mei_io_list_flush - removes list entry belonging to cl.
@@ -65,17 +50,15 @@ void mei_io_list_init(struct mei_io_list *list)
  * @list:  An instance of our list structure
  * @cl: private data of the file object
  */
-void mei_io_list_flush(struct mei_io_list *list, struct mei_cl *cl)
+void mei_io_list_flush(struct mei_cl_cb *list, struct mei_cl *cl)
 {
 	struct mei_cl_cb *pos;
 	struct mei_cl_cb *next;
 
-	list_for_each_entry_safe(pos, next, &list->mei_cb.cb_list, cb_list) {
-		if (pos->file_private) {
-			struct mei_cl *cl_tmp;
-			cl_tmp = (struct mei_cl *)pos->file_private;
-			if (mei_cl_cmp_id(cl, cl_tmp))
-				list_del(&pos->cb_list);
+	list_for_each_entry_safe(pos, next, &list->list, list) {
+		if (pos->cl) {
+			if (mei_cl_cmp_id(cl, pos->cl))
+				list_del(&pos->list);
 		}
 	}
 }
@@ -96,31 +79,14 @@ int mei_cl_flush_queues(struct mei_cl *cl)
 	mei_io_list_flush(&cl->dev->write_waiting_list, cl);
 	mei_io_list_flush(&cl->dev->ctrl_wr_list, cl);
 	mei_io_list_flush(&cl->dev->ctrl_rd_list, cl);
-	mei_io_list_flush(&cl->dev->amthi_cmd_list, cl);
-	mei_io_list_flush(&cl->dev->amthi_read_complete_list, cl);
+	mei_io_list_flush(&cl->dev->amthif_cmd_list, cl);
+	mei_io_list_flush(&cl->dev->amthif_rd_complete_list, cl);
 	return 0;
 }
 
 
 
 /**
- * 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 = false;
-	dev->iamthif_ioctl = false;
-	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
@@ -144,16 +110,14 @@ struct mei_device *mei_device_init(struct pci_dev *pdev)
 	init_waitqueue_head(&dev->wait_stop_wd);
 	dev->dev_state = MEI_DEV_INITIALIZING;
 	dev->iamthif_state = MEI_IAMTHIF_IDLE;
-	dev->wd_interface_reg = false;
-
 
 	mei_io_list_init(&dev->read_list);
 	mei_io_list_init(&dev->write_list);
 	mei_io_list_init(&dev->write_waiting_list);
 	mei_io_list_init(&dev->ctrl_wr_list);
 	mei_io_list_init(&dev->ctrl_rd_list);
-	mei_io_list_init(&dev->amthi_cmd_list);
-	mei_io_list_init(&dev->amthi_read_complete_list);
+	mei_io_list_init(&dev->amthif_cmd_list);
+	mei_io_list_init(&dev->amthif_rd_complete_list);
 	dev->pdev = pdev;
 	return dev;
 }
@@ -196,7 +160,8 @@ int mei_hw_init(struct mei_device *dev)
 	if (!dev->recvd_msg) {
 		mutex_unlock(&dev->device_lock);
 		err = wait_event_interruptible_timeout(dev->wait_recvd_msg,
-			dev->recvd_msg, MEI_INTEROP_TIMEOUT);
+			dev->recvd_msg,
+			mei_secs_to_jiffies(MEI_INTEROP_TIMEOUT));
 		mutex_lock(&dev->device_lock);
 	}
 
@@ -317,15 +282,13 @@ void mei_reset(struct mei_device *dev, int interrupts_enabled)
 			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);
+		dev_dbg(&dev->pdev->dev, "remove iamthif and wd from the file list.\n");
+		mei_me_cl_unlink(dev, &dev->wd_cl);
 
-		mei_remove_client_from_file_list(dev,
-				dev->iamthif_cl.host_client_id);
+		mei_me_cl_unlink(dev, &dev->iamthif_cl);
 
-		mei_reset_iamthif_params(dev);
-		dev->extra_write_index = 0;
+		mei_amthif_reset_params(dev);
+		memset(&dev->wr_ext_msg, 0, sizeof(dev->wr_ext_msg));
 	}
 
 	dev->me_clients_num = 0;
@@ -351,10 +314,9 @@ void mei_reset(struct mei_device *dev, int interrupts_enabled)
 		}
 	}
 	/* remove all waiting requests */
-	list_for_each_entry_safe(cb_pos, cb_next,
-			&dev->write_list.mei_cb.cb_list, cb_list) {
-		list_del(&cb_pos->cb_list);
-		mei_free_cb_private(cb_pos);
+	list_for_each_entry_safe(cb_pos, cb_next, &dev->write_list.list, list) {
+		list_del(&cb_pos->list);
+		mei_io_cb_free(cb_pos);
 	}
 }
 
@@ -370,31 +332,26 @@ void mei_reset(struct mei_device *dev, int interrupts_enabled)
 void mei_host_start_message(struct mei_device *dev)
 {
 	struct mei_msg_hdr *mei_hdr;
-	struct hbm_host_version_request *host_start_req;
+	struct hbm_host_version_request *start_req;
+	const size_t len = sizeof(struct hbm_host_version_request);
+
+	mei_hdr = mei_hbm_hdr(&dev->wr_msg_buf[0], len);
 
 	/* 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->hbm_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;
+	start_req = (struct hbm_host_version_request *)&dev->wr_msg_buf[1];
+	memset(start_req, 0, len);
+	start_req->hbm_cmd = HOST_START_REQ_CMD;
+	start_req->host_version.major_version = HBM_MAJOR_VERSION;
+	start_req->host_version.minor_version = HBM_MINOR_VERSION;
+
 	dev->recvd_msg = false;
-	if (mei_write_message(dev, mei_hdr, (unsigned char *)host_start_req,
-				       mei_hdr->length)) {
+	if (mei_write_message(dev, mei_hdr, (unsigned char *)start_req, len)) {
 		dev_dbg(&dev->pdev->dev, "write send version message to FW fail.\n");
 		dev->dev_state = MEI_DEV_RESETING;
 		mei_reset(dev, 1);
 	}
 	dev->init_clients_state = MEI_START_MESSAGE;
-	dev->init_clients_timer = INIT_CLIENTS_TIMEOUT;
+	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
 	return ;
 }
 
@@ -408,26 +365,22 @@ void mei_host_start_message(struct mei_device *dev)
 void mei_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];
+	struct hbm_host_enum_request *enum_req;
+	const size_t len = sizeof(struct hbm_host_enum_request);
 	/* 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->hbm_cmd = HOST_ENUM_REQ_CMD;
-	if (mei_write_message(dev, mei_hdr, (unsigned char *)host_enum_req,
-				mei_hdr->length)) {
+	mei_hdr = mei_hbm_hdr(&dev->wr_msg_buf[0], len);
+
+	enum_req = (struct hbm_host_enum_request *) &dev->wr_msg_buf[1];
+	memset(enum_req, 0, sizeof(struct hbm_host_enum_request));
+	enum_req->hbm_cmd = HOST_ENUM_REQ_CMD;
+
+	if (mei_write_message(dev, mei_hdr, (unsigned char *)enum_req, len)) {
 		dev->dev_state = MEI_DEV_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;
+	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
 	return;
 }
 
@@ -470,56 +423,87 @@ void mei_allocate_me_clients_storage(struct mei_device *dev)
 	dev->me_clients = clients;
 	return ;
 }
-/**
- * host_client_properties - reads properties for client
- *
- * @dev: the device structure
- *
- * returns:
- * 	< 0 - Error.
- *  = 0 - no more clients.
- *  = 1 - still have clients to send properties request.
- */
-int mei_host_client_properties(struct mei_device *dev)
+
+void mei_host_client_init(struct work_struct *work)
 {
-	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->hbm_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->dev_state = MEI_DEV_RESETING;
-			dev_dbg(&dev->pdev->dev, "write send enumeration request message to FW fail.\n");
-			mei_reset(dev, 1);
-			return -EIO;
-		}
+	struct mei_device *dev = container_of(work,
+					      struct mei_device, init_work);
+	struct mei_client_properties *client_props;
+	int i;
+
+	mutex_lock(&dev->device_lock);
+
+	bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
+	dev->open_handle_count = 0;
+
+	/*
+	 * Reserving the first three client IDs
+	 * 0: Reserved for MEI Bus Message communications
+	 * 1: Reserved for Watchdog
+	 * 2: Reserved for AMTHI
+	 */
+	bitmap_set(dev->host_clients_map, 0, 3);
+
+	for (i = 0; i < dev->me_clients_num; i++) {
+		client_props = &dev->me_clients[i].props;
+
+		if (!uuid_le_cmp(client_props->protocol_name, mei_amthi_guid))
+			mei_amthif_host_init(dev);
+		else if (!uuid_le_cmp(client_props->protocol_name, mei_wd_guid))
+			mei_wd_host_init(dev);
+	}
+
+	dev->dev_state = MEI_DEV_ENABLED;
 
-		dev->init_clients_timer = INIT_CLIENTS_TIMEOUT;
-		dev->me_client_index = b;
-		return 1;
+	mutex_unlock(&dev->device_lock);
+}
+
+int mei_host_client_enumerate(struct mei_device *dev)
+{
+
+	struct mei_msg_hdr *mei_hdr;
+	struct hbm_props_request *prop_req;
+	const size_t len = sizeof(struct hbm_props_request);
+	unsigned long next_client_index;
+	u8 client_num;
+
+
+	client_num = dev->me_client_presentation_num;
+
+	next_client_index = find_next_bit(dev->me_clients_map, MEI_CLIENTS_MAX,
+					  dev->me_client_index);
+
+	/* We got all client properties */
+	if (next_client_index == MEI_CLIENTS_MAX) {
+		schedule_work(&dev->init_work);
+
+		return 0;
 	}
 
+	dev->me_clients[client_num].client_id = next_client_index;
+	dev->me_clients[client_num].mei_flow_ctrl_creds = 0;
+
+	mei_hdr = mei_hbm_hdr(&dev->wr_msg_buf[0], len);
+	prop_req = (struct hbm_props_request *)&dev->wr_msg_buf[1];
+
+	memset(prop_req, 0, sizeof(struct hbm_props_request));
+
+
+	prop_req->hbm_cmd = HOST_CLIENT_PROPERTIES_REQ_CMD;
+	prop_req->address = next_client_index;
+
+	if (mei_write_message(dev, mei_hdr, (unsigned char *) prop_req,
+			      mei_hdr->length)) {
+		dev->dev_state = MEI_DEV_RESETING;
+		dev_err(&dev->pdev->dev, "Properties request command failed\n");
+		mei_reset(dev, 1);
+
+		return -EIO;
+	}
+
+	dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
+	dev->me_client_index = next_client_index;
+
 	return 0;
 }
 
@@ -557,17 +541,20 @@ int mei_me_cl_by_uuid(const struct mei_device *dev, const uuid_le *cuuid)
 
 
 /**
- * mei_me_cl_update_filext - searches for ME client guid
- *                       sets client_id in mei_file_private if found
+ * mei_me_cl_link - create link between host and me clinet and add
+ *   me_cl to the list
+ *
  * @dev: the device structure
- * @cl: private file structure to set client_id in
- * @cuuid: searched uuid of ME client
- * @client_id: id of host client to be set in file private structure
+ * @cl: link between me and host client assocated with opened file descriptor
+ * @cuuid: uuid of ME client
+ * @client_id: id of the host client
  *
- * returns ME client index
+ * returns ME client index if ME client
+ *	-EINVAL on incorrect values
+ *	-ENONET if client not found
  */
-int mei_me_cl_update_filext(struct mei_device *dev, struct mei_cl *cl,
-				const uuid_le *cuuid, u8 host_cl_id)
+int mei_me_cl_link(struct mei_device *dev, struct mei_cl *cl,
+			const uuid_le *cuuid, u8 host_cl_id)
 {
 	int i;
 
@@ -587,54 +574,22 @@ int mei_me_cl_update_filext(struct mei_device *dev, struct mei_cl *cl,
 
 	return -ENOENT;
 }
-
 /**
- * host_init_iamthif - mei initialization iamthif client.
+ * mei_me_cl_unlink - remove me_cl from the list
  *
  * @dev: the device structure
- *
+ * @host_client_id: host client id to be removed
  */
-void mei_host_init_iamthif(struct mei_device *dev)
+void mei_me_cl_unlink(struct mei_device *dev, struct mei_cl *cl)
 {
-	int i;
-	unsigned char *msg_buf;
-
-	mei_cl_init(&dev->iamthif_cl, dev);
-	dev->iamthif_cl.state = MEI_FILE_DISCONNECTED;
-
-	/* find ME amthi client */
-	i = mei_me_cl_update_filext(dev, &dev->iamthif_cl,
-			    &mei_amthi_guid, MEI_IAMTHIF_HOST_CLIENT_ID);
-	if (i < 0) {
-		dev_dbg(&dev->pdev->dev, "failed to find iamthif client.\n");
-		return;
-	}
-
-	/* Assign iamthif_mtu to the value received from ME  */
-
-	dev->iamthif_mtu = dev->me_clients[i].props.max_msg_length;
-	dev_dbg(&dev->pdev->dev, "IAMTHIF_MTU = %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;
+	struct mei_cl *pos, *next;
+	list_for_each_entry_safe(pos, next, &dev->file_list, link) {
+		if (cl->host_client_id == pos->host_client_id) {
+			dev_dbg(&dev->pdev->dev, "remove host client = %d, ME client = %d\n",
+					pos->host_client_id, pos->me_client_id);
+			list_del_init(&pos->link);
+			break;
+		}
 	}
 }
 
@@ -671,9 +626,8 @@ struct mei_cl *mei_cl_allocate(struct mei_device *dev)
  */
 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;
+	int rets, err;
 
 	if (!dev || !cl)
 		return -ENODEV;
@@ -681,13 +635,11 @@ int mei_disconnect_host_client(struct mei_device *dev, struct mei_cl *cl)
 	if (cl->state != MEI_FILE_DISCONNECTING)
 		return 0;
 
-	cb = kzalloc(sizeof(struct mei_cl_cb), GFP_KERNEL);
+	cb = mei_io_cb_init(cl, NULL);
 	if (!cb)
 		return -ENOMEM;
 
-	INIT_LIST_HEAD(&cb->cb_list);
-	cb->file_private = cl;
-	cb->major_file_operations = MEI_CLOSE;
+	cb->fop_type = MEI_FOP_CLOSE;
 	if (dev->mei_host_buffer_is_empty) {
 		dev->mei_host_buffer_is_empty = false;
 		if (mei_disconnect(dev, cl)) {
@@ -696,17 +648,17 @@ int mei_disconnect_host_client(struct mei_device *dev, struct mei_cl *cl)
 			goto free;
 		}
 		mdelay(10); /* Wait for hardware disconnection ready */
-		list_add_tail(&cb->cb_list, &dev->ctrl_rd_list.mei_cb.cb_list);
+		list_add_tail(&cb->list, &dev->ctrl_rd_list.list);
 	} 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);
+		list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
+
 	}
 	mutex_unlock(&dev->device_lock);
 
 	err = wait_event_timeout(dev->wait_recvd_msg,
-		 (MEI_FILE_DISCONNECTED == cl->state),
-		 timeout * HZ);
+			MEI_FILE_DISCONNECTED == cl->state,
+			mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
 
 	mutex_lock(&dev->device_lock);
 	if (MEI_FILE_DISCONNECTED == cl->state) {
@@ -728,29 +680,7 @@ int mei_disconnect_host_client(struct mei_device *dev, struct mei_cl *cl)
 	mei_io_list_flush(&dev->ctrl_rd_list, cl);
 	mei_io_list_flush(&dev->ctrl_wr_list, cl);
 free:
-	mei_free_cb_private(cb);
+	mei_io_cb_free(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;
-		}
-	}
-}
diff --git a/drivers/misc/mei/interface.c b/drivers/misc/mei/interface.c
index 509c3957ff45..8de854785960 100644
--- a/drivers/misc/mei/interface.c
+++ b/drivers/misc/mei/interface.c
@@ -292,28 +292,23 @@ int mei_flow_ctrl_reduce(struct mei_device *dev, struct mei_cl *cl)
 int mei_send_flow_control(struct mei_device *dev, struct mei_cl *cl)
 {
 	struct mei_msg_hdr *mei_hdr;
-	struct hbm_flow_control *mei_flow_control;
-
-	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_flow_control);
-	mei_hdr->msg_complete = 1;
-	mei_hdr->reserved = 0;
-
-	mei_flow_control = (struct hbm_flow_control *) &dev->wr_msg_buf[1];
-	memset(mei_flow_control, 0, sizeof(*mei_flow_control));
-	mei_flow_control->host_addr = cl->host_client_id;
-	mei_flow_control->me_addr = cl->me_client_id;
-	mei_flow_control->hbm_cmd = MEI_FLOW_CONTROL_CMD;
-	memset(mei_flow_control->reserved, 0,
-			sizeof(mei_flow_control->reserved));
+	struct hbm_flow_control *flow_ctrl;
+	const size_t len = sizeof(struct hbm_flow_control);
+
+	mei_hdr = mei_hbm_hdr(&dev->wr_msg_buf[0], len);
+
+	flow_ctrl = (struct hbm_flow_control *)&dev->wr_msg_buf[1];
+	memset(flow_ctrl, 0, len);
+	flow_ctrl->hbm_cmd = MEI_FLOW_CONTROL_CMD;
+	flow_ctrl->host_addr = cl->host_client_id;
+	flow_ctrl->me_addr = cl->me_client_id;
+	/* FIXME: reserved !? */
+	memset(flow_ctrl->reserved, 0, sizeof(flow_ctrl->reserved));
 	dev_dbg(&dev->pdev->dev, "sending flow control host client = %d, ME client = %d\n",
 		cl->host_client_id, cl->me_client_id);
 
 	return mei_write_message(dev, mei_hdr,
-				(unsigned char *) mei_flow_control,
-				sizeof(struct hbm_flow_control));
+			(unsigned char *) flow_ctrl, len);
 }
 
 /**
@@ -352,26 +347,19 @@ int mei_other_client_is_connecting(struct mei_device *dev,
 int mei_disconnect(struct mei_device *dev, struct mei_cl *cl)
 {
 	struct mei_msg_hdr *mei_hdr;
-	struct hbm_client_disconnect_request *mei_cli_disconnect;
-
-	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_client_disconnect_request);
-	mei_hdr->msg_complete = 1;
-	mei_hdr->reserved = 0;
-
-	mei_cli_disconnect =
-	    (struct hbm_client_disconnect_request *) &dev->wr_msg_buf[1];
-	memset(mei_cli_disconnect, 0, sizeof(*mei_cli_disconnect));
-	mei_cli_disconnect->host_addr = cl->host_client_id;
-	mei_cli_disconnect->me_addr = cl->me_client_id;
-	mei_cli_disconnect->hbm_cmd = CLIENT_DISCONNECT_REQ_CMD;
-	mei_cli_disconnect->reserved[0] = 0;
+	struct hbm_client_connect_request *req;
+	const size_t len = sizeof(struct hbm_client_connect_request);
 
-	return mei_write_message(dev, mei_hdr,
-				(unsigned char *) mei_cli_disconnect,
-				sizeof(struct hbm_client_disconnect_request));
+	mei_hdr = mei_hbm_hdr(&dev->wr_msg_buf[0], len);
+
+	req = (struct hbm_client_connect_request *)&dev->wr_msg_buf[1];
+	memset(req, 0, len);
+	req->hbm_cmd = CLIENT_DISCONNECT_REQ_CMD;
+	req->host_addr = cl->host_client_id;
+	req->me_addr = cl->me_client_id;
+	req->reserved = 0;
+
+	return mei_write_message(dev, mei_hdr, (unsigned char *)req, len);
 }
 
 /**
@@ -385,23 +373,16 @@ int mei_disconnect(struct mei_device *dev, struct mei_cl *cl)
 int mei_connect(struct mei_device *dev, struct mei_cl *cl)
 {
 	struct mei_msg_hdr *mei_hdr;
-	struct hbm_client_connect_request *mei_cli_connect;
-
-	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_client_connect_request);
-	mei_hdr->msg_complete = 1;
-	mei_hdr->reserved = 0;
-
-	mei_cli_connect =
-	    (struct hbm_client_connect_request *) &dev->wr_msg_buf[1];
-	mei_cli_connect->host_addr = cl->host_client_id;
-	mei_cli_connect->me_addr = cl->me_client_id;
-	mei_cli_connect->hbm_cmd = CLIENT_CONNECT_REQ_CMD;
-	mei_cli_connect->reserved = 0;
+	struct hbm_client_connect_request *req;
+	const size_t len = sizeof(struct hbm_client_connect_request);
 
-	return mei_write_message(dev, mei_hdr,
-				(unsigned char *) mei_cli_connect,
-				sizeof(struct hbm_client_connect_request));
+	mei_hdr = mei_hbm_hdr(&dev->wr_msg_buf[0], len);
+
+	req = (struct hbm_client_connect_request *) &dev->wr_msg_buf[1];
+	req->hbm_cmd = CLIENT_CONNECT_REQ_CMD;
+	req->host_addr = cl->host_client_id;
+	req->me_addr = cl->me_client_id;
+	req->reserved = 0;
+
+	return mei_write_message(dev, mei_hdr, (unsigned char *) req, len);
 }
diff --git a/drivers/misc/mei/interrupt.c b/drivers/misc/mei/interrupt.c
index 3533edde04a5..04fa2134615e 100644
--- a/drivers/misc/mei/interrupt.c
+++ b/drivers/misc/mei/interrupt.c
@@ -57,14 +57,14 @@ irqreturn_t mei_interrupt_quick_handler(int irq, void *dev_id)
  */
 static void _mei_cmpl(struct mei_cl *cl, struct mei_cl_cb *cb_pos)
 {
-	if (cb_pos->major_file_operations == MEI_WRITE) {
-		mei_free_cb_private(cb_pos);
+	if (cb_pos->fop_type == MEI_FOP_WRITE) {
+		mei_io_cb_free(cb_pos);
 		cb_pos = NULL;
 		cl->writing_state = MEI_WRITE_COMPLETE;
 		if (waitqueue_active(&cl->tx_wait))
 			wake_up_interruptible(&cl->tx_wait);
 
-	} else if (cb_pos->major_file_operations == MEI_READ &&
+	} else if (cb_pos->fop_type == MEI_FOP_READ &&
 			MEI_READING == cl->reading_state) {
 		cl->reading_state = MEI_READ_COMPLETE;
 		if (waitqueue_active(&cl->rx_wait))
@@ -74,94 +74,6 @@ static void _mei_cmpl(struct mei_cl *cl, struct mei_cl_cb *cb_pos)
 }
 
 /**
- * _mei_cmpl_iamthif - processes completed iamthif operation.
- *
- * @dev: the device structure.
- * @cb_pos: callback block.
- */
-static void _mei_cmpl_iamthif(struct mei_device *dev, struct mei_cl_cb *cb_pos)
-{
-	if (dev->iamthif_canceled != 1) {
-		dev->iamthif_state = MEI_IAMTHIF_READ_COMPLETE;
-		dev->iamthif_stall_timer = 0;
-		memcpy(cb_pos->response_buffer.data,
-				dev->iamthif_msg_buf,
-				dev->iamthif_msg_buf_index);
-		list_add_tail(&cb_pos->cb_list,
-				&dev->amthi_read_complete_list.mei_cb.cb_list);
-		dev_dbg(&dev->pdev->dev, "amthi read completed.\n");
-		dev->iamthif_timer = jiffies;
-		dev_dbg(&dev->pdev->dev, "dev->iamthif_timer = %ld\n",
-				dev->iamthif_timer);
-	} else {
-		mei_run_next_iamthif_cmd(dev);
-	}
-
-	dev_dbg(&dev->pdev->dev, "completing amthi call back.\n");
-	wake_up_interruptible(&dev->iamthif_cl.wait);
-}
-
-
-/**
- * mei_irq_thread_read_amthi_message - bottom half read routine after ISR to
- * handle the read amthi message data processing.
- *
- * @complete_list: An instance of our list structure
- * @dev: the device structure
- * @mei_hdr: header of amthi message
- *
- * returns 0 on success, <0 on failure.
- */
-static int mei_irq_thread_read_amthi_message(struct mei_io_list *complete_list,
-		struct mei_device *dev,
-		struct mei_msg_hdr *mei_hdr)
-{
-	struct mei_cl *cl;
-	struct mei_cl_cb *cb;
-	unsigned char *buffer;
-
-	BUG_ON(mei_hdr->me_addr != dev->iamthif_cl.me_client_id);
-	BUG_ON(dev->iamthif_state != MEI_IAMTHIF_READING);
-
-	buffer = dev->iamthif_msg_buf + dev->iamthif_msg_buf_index;
-	BUG_ON(dev->iamthif_mtu < dev->iamthif_msg_buf_index + mei_hdr->length);
-
-	mei_read_slots(dev, buffer, mei_hdr->length);
-
-	dev->iamthif_msg_buf_index += mei_hdr->length;
-
-	if (!mei_hdr->msg_complete)
-		return 0;
-
-	dev_dbg(&dev->pdev->dev,
-			"amthi_message_buffer_index =%d\n",
-			mei_hdr->length);
-
-	dev_dbg(&dev->pdev->dev, "completed amthi read.\n ");
-	if (!dev->iamthif_current_cb)
-		return -ENODEV;
-
-	cb = dev->iamthif_current_cb;
-	dev->iamthif_current_cb = NULL;
-
-	cl = (struct mei_cl *)cb->file_private;
-	if (!cl)
-		return -ENODEV;
-
-	dev->iamthif_stall_timer = 0;
-	cb->information =	dev->iamthif_msg_buf_index;
-	cb->read_time = jiffies;
-	if (dev->iamthif_ioctl && cl == &dev->iamthif_cl) {
-		/* found the iamthif cb */
-		dev_dbg(&dev->pdev->dev, "complete the amthi read cb.\n ");
-		dev_dbg(&dev->pdev->dev, "add the amthi read cb to complete.\n ");
-		list_add_tail(&cb->cb_list,
-						&complete_list->mei_cb.cb_list);
-	}
-	return 0;
-}
-
-/**
  * _mei_irq_thread_state_ok - checks if mei header matches file private data
  *
  * @cl: private data of the file object
@@ -188,7 +100,7 @@ static int _mei_irq_thread_state_ok(struct mei_cl *cl,
  *
  * returns 0 on success, <0 on failure.
  */
-static int mei_irq_thread_read_client_message(struct mei_io_list *complete_list,
+static int mei_irq_thread_read_client_message(struct mei_cl_cb *complete_list,
 		struct mei_device *dev,
 		struct mei_msg_hdr *mei_hdr)
 {
@@ -197,36 +109,36 @@ static int mei_irq_thread_read_client_message(struct mei_io_list *complete_list,
 	unsigned char *buffer = NULL;
 
 	dev_dbg(&dev->pdev->dev, "start client msg\n");
-	if (list_empty(&dev->read_list.mei_cb.cb_list))
+	if (list_empty(&dev->read_list.list))
 		goto quit;
 
-	list_for_each_entry_safe(cb_pos, cb_next,
-			&dev->read_list.mei_cb.cb_list, cb_list) {
-		cl = (struct mei_cl *)cb_pos->file_private;
+	list_for_each_entry_safe(cb_pos, cb_next, &dev->read_list.list, list) {
+		cl = cb_pos->cl;
 		if (cl && _mei_irq_thread_state_ok(cl, mei_hdr)) {
 			cl->reading_state = MEI_READING;
-			buffer = cb_pos->response_buffer.data + cb_pos->information;
+			buffer = cb_pos->response_buffer.data + cb_pos->buf_idx;
 
 			if (cb_pos->response_buffer.size <
-					mei_hdr->length + cb_pos->information) {
+					mei_hdr->length + cb_pos->buf_idx) {
 				dev_dbg(&dev->pdev->dev, "message overflow.\n");
-				list_del(&cb_pos->cb_list);
+				list_del(&cb_pos->list);
 				return -ENOMEM;
 			}
 			if (buffer)
 				mei_read_slots(dev, buffer, mei_hdr->length);
 
-			cb_pos->information += mei_hdr->length;
+			cb_pos->buf_idx += mei_hdr->length;
 			if (mei_hdr->msg_complete) {
 				cl->status = 0;
-				list_del(&cb_pos->cb_list);
+				list_del(&cb_pos->list);
 				dev_dbg(&dev->pdev->dev,
 					"completed read H cl = %d, ME cl = %d, length = %lu\n",
 					cl->host_client_id,
 					cl->me_client_id,
-					cb_pos->information);
-				list_add_tail(&cb_pos->cb_list,
-					&complete_list->mei_cb.cb_list);
+					cb_pos->buf_idx);
+
+				list_add_tail(&cb_pos->list,
+						&complete_list->list);
 			}
 
 			break;
@@ -246,37 +158,6 @@ quit:
 }
 
 /**
- * _mei_irq_thread_iamthif_read - prepares to read iamthif data.
- *
- * @dev: the device structure.
- * @slots: free slots.
- *
- * returns 0, OK; otherwise, error.
- */
-static int _mei_irq_thread_iamthif_read(struct mei_device *dev, s32 *slots)
-{
-
-	if (((*slots) * sizeof(u32)) < (sizeof(struct mei_msg_hdr)
-			+ sizeof(struct hbm_flow_control))) {
-		return -EMSGSIZE;
-	}
-	*slots -= mei_data2slots(sizeof(struct hbm_flow_control));
-	if (mei_send_flow_control(dev, &dev->iamthif_cl)) {
-		dev_dbg(&dev->pdev->dev, "iamthif flow control failed\n");
-		return -EIO;
-	}
-
-	dev_dbg(&dev->pdev->dev, "iamthif flow control success\n");
-	dev->iamthif_state = MEI_IAMTHIF_READING;
-	dev->iamthif_flow_control_pending = false;
-	dev->iamthif_msg_buf_index = 0;
-	dev->iamthif_msg_buf_size = 0;
-	dev->iamthif_stall_timer = IAMTHIF_STALL_TIMER;
-	dev->mei_host_buffer_is_empty = mei_hbuf_is_empty(dev);
-	return 0;
-}
-
-/**
  * _mei_irq_thread_close - processes close related operation.
  *
  * @dev: the device structure.
@@ -290,26 +171,24 @@ static int _mei_irq_thread_iamthif_read(struct mei_device *dev, s32 *slots)
 static int _mei_irq_thread_close(struct mei_device *dev, s32 *slots,
 				struct mei_cl_cb *cb_pos,
 				struct mei_cl *cl,
-				struct mei_io_list *cmpl_list)
+				struct mei_cl_cb *cmpl_list)
 {
 	if ((*slots * sizeof(u32)) < (sizeof(struct mei_msg_hdr) +
-			sizeof(struct hbm_client_disconnect_request)))
+			sizeof(struct hbm_client_connect_request)))
 		return -EBADMSG;
 
-	*slots -= mei_data2slots(sizeof(struct hbm_client_disconnect_request));
+	*slots -= mei_data2slots(sizeof(struct hbm_client_connect_request));
 
 	if (mei_disconnect(dev, cl)) {
 		cl->status = 0;
-		cb_pos->information = 0;
-		list_move_tail(&cb_pos->cb_list,
-				&cmpl_list->mei_cb.cb_list);
+		cb_pos->buf_idx = 0;
+		list_move_tail(&cb_pos->list, &cmpl_list->list);
 		return -EMSGSIZE;
 	} else {
 		cl->state = MEI_FILE_DISCONNECTING;
 		cl->status = 0;
-		cb_pos->information = 0;
-		list_move_tail(&cb_pos->cb_list,
-				&dev->ctrl_rd_list.mei_cb.cb_list);
+		cb_pos->buf_idx = 0;
+		list_move_tail(&cb_pos->list, &dev->ctrl_rd_list.list);
 		cl->timer_count = MEI_CONNECT_TIMEOUT;
 	}
 
@@ -356,7 +235,7 @@ static void mei_client_connect_response(struct mei_device *dev,
 {
 
 	struct mei_cl *cl;
-	struct mei_cl_cb *cb_pos = NULL, *cb_next = NULL;
+	struct mei_cl_cb *pos = NULL, *next = NULL;
 
 	dev_dbg(&dev->pdev->dev,
 			"connect_response:\n"
@@ -373,8 +252,6 @@ static void mei_client_connect_response(struct mei_device *dev,
 		dev_dbg(&dev->pdev->dev, "successfully connected to WD client.\n");
 		mei_watchdog_register(dev);
 
-		/* next step in the state maching */
-		mei_host_init_iamthif(dev);
 		return;
 	}
 
@@ -382,17 +259,16 @@ static void mei_client_connect_response(struct mei_device *dev,
 		dev->iamthif_state = MEI_IAMTHIF_IDLE;
 		return;
 	}
-	list_for_each_entry_safe(cb_pos, cb_next,
-				&dev->ctrl_rd_list.mei_cb.cb_list, cb_list) {
+	list_for_each_entry_safe(pos, next, &dev->ctrl_rd_list.list, list) {
 
-		cl = (struct mei_cl *)cb_pos->file_private;
+		cl = pos->cl;
 		if (!cl) {
-			list_del(&cb_pos->cb_list);
+			list_del(&pos->list);
 			return;
 		}
-		if (MEI_IOCTL == cb_pos->major_file_operations) {
+		if (pos->fop_type == MEI_FOP_IOCTL) {
 			if (is_treat_specially_client(cl, rs)) {
-				list_del(&cb_pos->cb_list);
+				list_del(&pos->list);
 				cl->status = 0;
 				cl->timer_count = 0;
 				break;
@@ -411,7 +287,7 @@ static void mei_client_disconnect_response(struct mei_device *dev,
 					struct hbm_client_connect_response *rs)
 {
 	struct mei_cl *cl;
-	struct mei_cl_cb *cb_pos = NULL, *cb_next = NULL;
+	struct mei_cl_cb *pos = NULL, *next = NULL;
 
 	dev_dbg(&dev->pdev->dev,
 			"disconnect_response:\n"
@@ -422,12 +298,11 @@ static void mei_client_disconnect_response(struct mei_device *dev,
 			rs->host_addr,
 			rs->status);
 
-	list_for_each_entry_safe(cb_pos, cb_next,
-			&dev->ctrl_rd_list.mei_cb.cb_list, cb_list) {
-		cl = (struct mei_cl *)cb_pos->file_private;
+	list_for_each_entry_safe(pos, next, &dev->ctrl_rd_list.list, list) {
+		cl = pos->cl;
 
 		if (!cl) {
-			list_del(&cb_pos->cb_list);
+			list_del(&pos->list);
 			return;
 		}
 
@@ -435,7 +310,7 @@ static void mei_client_disconnect_response(struct mei_device *dev,
 		if (cl->host_client_id == rs->host_addr &&
 		    cl->me_client_id == rs->me_addr) {
 
-			list_del(&cb_pos->cb_list);
+			list_del(&pos->list);
 			if (!rs->status)
 				cl->state = MEI_FILE_DISCONNECTED;
 
@@ -537,10 +412,10 @@ static void mei_client_flow_control_response(struct mei_device *dev,
  * returns !=0, same; 0,not.
  */
 static int same_disconn_addr(struct mei_cl *cl,
-			     struct hbm_client_disconnect_request *disconn)
+			     struct hbm_client_connect_request *req)
 {
-	return (cl->host_client_id == disconn->host_addr &&
-		cl->me_client_id == disconn->me_addr);
+	return (cl->host_client_id == req->host_addr &&
+		cl->me_client_id == req->me_addr);
 }
 
 /**
@@ -550,49 +425,38 @@ static int same_disconn_addr(struct mei_cl *cl,
  * @disconnect_req: disconnect request bus message.
  */
 static void mei_client_disconnect_request(struct mei_device *dev,
-		struct hbm_client_disconnect_request *disconnect_req)
+		struct hbm_client_connect_request *disconnect_req)
 {
-	struct mei_msg_hdr *mei_hdr;
 	struct hbm_client_connect_response *disconnect_res;
-	struct mei_cl *cl_pos = NULL;
-	struct mei_cl *cl_next = NULL;
+	struct mei_cl *pos, *next;
+	const size_t len = sizeof(struct hbm_client_connect_response);
 
-	list_for_each_entry_safe(cl_pos, cl_next, &dev->file_list, link) {
-		if (same_disconn_addr(cl_pos, disconnect_req)) {
+	list_for_each_entry_safe(pos, next, &dev->file_list, link) {
+		if (same_disconn_addr(pos, disconnect_req)) {
 			dev_dbg(&dev->pdev->dev, "disconnect request host client %d ME client %d.\n",
 					disconnect_req->host_addr,
 					disconnect_req->me_addr);
-			cl_pos->state = MEI_FILE_DISCONNECTED;
-			cl_pos->timer_count = 0;
-			if (cl_pos == &dev->wd_cl)
+			pos->state = MEI_FILE_DISCONNECTED;
+			pos->timer_count = 0;
+			if (pos == &dev->wd_cl)
 				dev->wd_pending = false;
-			else if (cl_pos == &dev->iamthif_cl)
+			else if (pos == &dev->iamthif_cl)
 				dev->iamthif_timer = 0;
 
 			/* prepare disconnect response */
-			mei_hdr =
-				(struct mei_msg_hdr *) &dev->ext_msg_buf[0];
-			mei_hdr->host_addr = 0;
-			mei_hdr->me_addr = 0;
-			mei_hdr->length =
-				sizeof(struct hbm_client_connect_response);
-			mei_hdr->msg_complete = 1;
-			mei_hdr->reserved = 0;
-
+			(void)mei_hbm_hdr((u32 *)&dev->wr_ext_msg.hdr, len);
 			disconnect_res =
 				(struct hbm_client_connect_response *)
-				&dev->ext_msg_buf[1];
-			disconnect_res->host_addr = cl_pos->host_client_id;
-			disconnect_res->me_addr = cl_pos->me_client_id;
+				&dev->wr_ext_msg.data;
 			disconnect_res->hbm_cmd = CLIENT_DISCONNECT_RES_CMD;
+			disconnect_res->host_addr = pos->host_client_id;
+			disconnect_res->me_addr = pos->me_client_id;
 			disconnect_res->status = 0;
-			dev->extra_write_index = 2;
 			break;
 		}
 	}
 }
 
-
 /**
  * mei_irq_thread_read_bus_message - bottom half read routine after ISR to
  * handle the read bus message cmd processing.
@@ -604,16 +468,15 @@ static void mei_irq_thread_read_bus_message(struct mei_device *dev,
 		struct mei_msg_hdr *mei_hdr)
 {
 	struct mei_bus_message *mei_msg;
+	struct mei_me_client *me_client;
 	struct hbm_host_version_response *version_res;
 	struct hbm_client_connect_response *connect_res;
 	struct hbm_client_connect_response *disconnect_res;
+	struct hbm_client_connect_request *disconnect_req;
 	struct hbm_flow_control *flow_control;
 	struct hbm_props_response *props_res;
 	struct hbm_host_enum_response *enum_res;
-	struct hbm_client_disconnect_request *disconnect_req;
-	struct hbm_host_stop_request *host_stop_req;
-	int res;
-
+	struct hbm_host_stop_request *stop_req;
 
 	/* read the message to our buffer */
 	BUG_ON(mei_hdr->length >= sizeof(dev->rd_msg_buf));
@@ -637,26 +500,20 @@ static void mei_irq_thread_read_bus_message(struct mei_device *dev,
 				return;
 			}
 		} else {
+			u32 *buf = dev->wr_msg_buf;
+			const size_t len = sizeof(struct hbm_host_stop_request);
+
 			dev->version = version_res->me_max_version;
+
 			/* send stop 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_stop_request);
-			mei_hdr->msg_complete = 1;
-			mei_hdr->reserved = 0;
-
-			host_stop_req = (struct hbm_host_stop_request *)
-							&dev->wr_msg_buf[1];
-
-			memset(host_stop_req,
-					0,
-					sizeof(struct hbm_host_stop_request));
-			host_stop_req->hbm_cmd = HOST_STOP_REQ_CMD;
-			host_stop_req->reason = DRIVER_STOP_REQUEST;
+			mei_hdr = mei_hbm_hdr(&buf[0], len);
+			stop_req = (struct hbm_host_stop_request *)&buf[1];
+			memset(stop_req, 0, len);
+			stop_req->hbm_cmd = HOST_STOP_REQ_CMD;
+			stop_req->reason = DRIVER_STOP_REQUEST;
+
 			mei_write_message(dev, mei_hdr,
-					   (unsigned char *) (host_stop_req),
-					   mei_hdr->length);
+					(unsigned char *)stop_req, len);
 			dev_dbg(&dev->pdev->dev, "version mismatch.\n");
 			return;
 		}
@@ -666,16 +523,14 @@ static void mei_irq_thread_read_bus_message(struct mei_device *dev,
 		break;
 
 	case CLIENT_CONNECT_RES_CMD:
-		connect_res =
-			(struct hbm_client_connect_response *) mei_msg;
+		connect_res = (struct hbm_client_connect_response *) mei_msg;
 		mei_client_connect_response(dev, connect_res);
 		dev_dbg(&dev->pdev->dev, "client connect response message received.\n");
 		wake_up(&dev->wait_recvd_msg);
 		break;
 
 	case CLIENT_DISCONNECT_RES_CMD:
-		disconnect_res =
-			(struct hbm_client_connect_response *) mei_msg;
+		disconnect_res = (struct hbm_client_connect_response *) mei_msg;
 		mei_client_disconnect_response(dev, disconnect_res);
 		dev_dbg(&dev->pdev->dev, "client disconnect response message received.\n");
 		wake_up(&dev->wait_recvd_msg);
@@ -689,64 +544,37 @@ static void mei_irq_thread_read_bus_message(struct mei_device *dev,
 
 	case HOST_CLIENT_PROPERTIES_RES_CMD:
 		props_res = (struct hbm_props_response *)mei_msg;
+		me_client = &dev->me_clients[dev->me_client_presentation_num];
+
 		if (props_res->status || !dev->me_clients) {
 			dev_dbg(&dev->pdev->dev, "reset due to received host client properties response bus message wrong status.\n");
 			mei_reset(dev, 1);
 			return;
 		}
-		if (dev->me_clients[dev->me_client_presentation_num]
-					.client_id == props_res->address) {
 
-			dev->me_clients[dev->me_client_presentation_num].props
-						= props_res->client_properties;
+		if (me_client->client_id != props_res->address) {
+			dev_err(&dev->pdev->dev,
+				"Host client properties reply mismatch\n");
+			mei_reset(dev, 1);
 
-			if (dev->dev_state == MEI_DEV_INIT_CLIENTS &&
-			    dev->init_clients_state ==
-					MEI_CLIENT_PROPERTIES_MESSAGE) {
-				dev->me_client_index++;
-				dev->me_client_presentation_num++;
-
-				/** Send Client Properties request **/
-				res = mei_host_client_properties(dev);
-				if (res < 0) {
-					dev_dbg(&dev->pdev->dev, "mei_host_client_properties() failed");
-					return;
-				} else if (!res) {
-					/*
-					 * No more clients to send to.
-					 * Clear Map for indicating now ME clients
-					 * with associated host client
-					 */
-					bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
-					dev->open_handle_count = 0;
-
-					/*
-					 * Reserving the first three client IDs
-					 * Client Id 0 - Reserved for MEI Bus Message communications
-					 * Client Id 1 - Reserved for Watchdog
-					 * Client ID 2 - Reserved for AMTHI
-					 */
-					bitmap_set(dev->host_clients_map, 0, 3);
-					dev->dev_state = MEI_DEV_ENABLED;
-
-					/* if wd initialization fails, initialization the AMTHI client,
-					 * otherwise the AMTHI client will be initialized after the WD client connect response
-					 * will be received
-					 */
-					if (mei_wd_host_init(dev))
-						mei_host_init_iamthif(dev);
-				}
+			return;
+		}
 
-			} else {
-				dev_dbg(&dev->pdev->dev, "reset due to received host client properties response bus message");
-				mei_reset(dev, 1);
-				return;
-			}
-		} else {
-			dev_dbg(&dev->pdev->dev, "reset due to received host client properties response bus message for wrong client ID\n");
+		if (dev->dev_state != MEI_DEV_INIT_CLIENTS ||
+		    dev->init_clients_state != MEI_CLIENT_PROPERTIES_MESSAGE) {
+			dev_err(&dev->pdev->dev,
+				"Unexpected client properties reply\n");
 			mei_reset(dev, 1);
+
 			return;
 		}
+
+		me_client->props = props_res->client_properties;
+		dev->me_client_index++;
+		dev->me_client_presentation_num++;
+
+		mei_host_client_enumerate(dev);
+
 		break;
 
 	case HOST_ENUM_RES_CMD:
@@ -760,7 +588,8 @@ static void mei_irq_thread_read_bus_message(struct mei_device *dev,
 				mei_allocate_me_clients_storage(dev);
 				dev->init_clients_state =
 					MEI_CLIENT_PROPERTIES_MESSAGE;
-				mei_host_client_properties(dev);
+
+				mei_host_client_enumerate(dev);
 		} else {
 			dev_dbg(&dev->pdev->dev, "reset due to received host enumeration clients response bus message.\n");
 			mei_reset(dev, 1);
@@ -776,29 +605,23 @@ static void mei_irq_thread_read_bus_message(struct mei_device *dev,
 
 	case CLIENT_DISCONNECT_REQ_CMD:
 		/* search for client */
-		disconnect_req =
-			(struct hbm_client_disconnect_request *) mei_msg;
+		disconnect_req = (struct hbm_client_connect_request *)mei_msg;
 		mei_client_disconnect_request(dev, disconnect_req);
 		break;
 
 	case ME_STOP_REQ_CMD:
-		/* prepare stop request */
-		mei_hdr = (struct mei_msg_hdr *) &dev->ext_msg_buf[0];
-		mei_hdr->host_addr = 0;
-		mei_hdr->me_addr = 0;
-		mei_hdr->length = sizeof(struct hbm_host_stop_request);
-		mei_hdr->msg_complete = 1;
-		mei_hdr->reserved = 0;
-		host_stop_req =
-			(struct hbm_host_stop_request *) &dev->ext_msg_buf[1];
-		memset(host_stop_req, 0, sizeof(struct hbm_host_stop_request));
-		host_stop_req->hbm_cmd = HOST_STOP_REQ_CMD;
-		host_stop_req->reason = DRIVER_STOP_REQUEST;
-		host_stop_req->reserved[0] = 0;
-		host_stop_req->reserved[1] = 0;
-		dev->extra_write_index = 2;
-		break;
+	{
+		/* prepare stop request: sent in next interrupt event */
+
+		const size_t len = sizeof(struct hbm_host_stop_request);
 
+		mei_hdr = mei_hbm_hdr((u32 *)&dev->wr_ext_msg.hdr, len);
+		stop_req = (struct hbm_host_stop_request *)&dev->wr_ext_msg.data;
+		memset(stop_req, 0, len);
+		stop_req->hbm_cmd = HOST_STOP_REQ_CMD;
+		stop_req->reason = DRIVER_STOP_REQUEST;
+		break;
+	}
 	default:
 		BUG();
 		break;
@@ -821,12 +644,12 @@ static void mei_irq_thread_read_bus_message(struct mei_device *dev,
 static int _mei_irq_thread_read(struct mei_device *dev,	s32 *slots,
 			struct mei_cl_cb *cb_pos,
 			struct mei_cl *cl,
-			struct mei_io_list *cmpl_list)
+			struct mei_cl_cb *cmpl_list)
 {
 	if ((*slots * sizeof(u32)) < (sizeof(struct mei_msg_hdr) +
 			sizeof(struct hbm_flow_control))) {
 		/* return the cancel routine */
-		list_del(&cb_pos->cb_list);
+		list_del(&cb_pos->list);
 		return -EBADMSG;
 	}
 
@@ -834,11 +657,11 @@ static int _mei_irq_thread_read(struct mei_device *dev,	s32 *slots,
 
 	if (mei_send_flow_control(dev, cl)) {
 		cl->status = -ENODEV;
-		cb_pos->information = 0;
-		list_move_tail(&cb_pos->cb_list, &cmpl_list->mei_cb.cb_list);
+		cb_pos->buf_idx = 0;
+		list_move_tail(&cb_pos->list, &cmpl_list->list);
 		return -ENODEV;
 	}
-	list_move_tail(&cb_pos->cb_list, &dev->read_list.mei_cb.cb_list);
+	list_move_tail(&cb_pos->list, &dev->read_list.list);
 
 	return 0;
 }
@@ -858,12 +681,12 @@ static int _mei_irq_thread_read(struct mei_device *dev,	s32 *slots,
 static int _mei_irq_thread_ioctl(struct mei_device *dev, s32 *slots,
 			struct mei_cl_cb *cb_pos,
 			struct mei_cl *cl,
-			struct mei_io_list *cmpl_list)
+			struct mei_cl_cb *cmpl_list)
 {
 	if ((*slots * sizeof(u32)) < (sizeof(struct mei_msg_hdr) +
 			sizeof(struct hbm_client_connect_request))) {
 		/* return the cancel routine */
-		list_del(&cb_pos->cb_list);
+		list_del(&cb_pos->list);
 		return -EBADMSG;
 	}
 
@@ -871,188 +694,73 @@ static int _mei_irq_thread_ioctl(struct mei_device *dev, s32 *slots,
 	 *slots -= mei_data2slots(sizeof(struct hbm_client_connect_request));
 	if (mei_connect(dev, cl)) {
 		cl->status = -ENODEV;
-		cb_pos->information = 0;
-		list_del(&cb_pos->cb_list);
+		cb_pos->buf_idx = 0;
+		list_del(&cb_pos->list);
 		return -ENODEV;
 	} else {
-		list_move_tail(&cb_pos->cb_list,
-			&dev->ctrl_rd_list.mei_cb.cb_list);
+		list_move_tail(&cb_pos->list, &dev->ctrl_rd_list.list);
 		cl->timer_count = MEI_CONNECT_TIMEOUT;
 	}
 	return 0;
 }
 
 /**
- * _mei_irq_thread_cmpl - processes completed and no-iamthif operation.
+ * mei_irq_thread_write_complete - write messages to device.
  *
  * @dev: the device structure.
  * @slots: free slots.
- * @cb_pos: callback block.
- * @cl: private data of the file object.
+ * @cb: callback block.
  * @cmpl_list: complete list.
  *
  * returns 0, OK; otherwise, error.
  */
-static int _mei_irq_thread_cmpl(struct mei_device *dev,	s32 *slots,
-			struct mei_cl_cb *cb_pos,
-			struct mei_cl *cl,
-			struct mei_io_list *cmpl_list)
+static int mei_irq_thread_write_complete(struct mei_device *dev, s32 *slots,
+			struct mei_cl_cb *cb, struct mei_cl_cb *cmpl_list)
 {
 	struct mei_msg_hdr *mei_hdr;
+	struct mei_cl *cl = cb->cl;
+	size_t len = cb->request_buffer.size - cb->buf_idx;
+	size_t msg_slots = mei_data2slots(len);
+
+	mei_hdr = (struct mei_msg_hdr *)&dev->wr_msg_buf[0];
+	mei_hdr->host_addr = cl->host_client_id;
+	mei_hdr->me_addr = cl->me_client_id;
+	mei_hdr->reserved = 0;
 
-	if ((*slots * sizeof(u32)) >= (sizeof(struct mei_msg_hdr) +
-			(cb_pos->request_buffer.size -
-			cb_pos->information))) {
-		mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
-		mei_hdr->host_addr = cl->host_client_id;
-		mei_hdr->me_addr = cl->me_client_id;
-		mei_hdr->length = cb_pos->request_buffer.size -
-					cb_pos->information;
+	if (*slots >= msg_slots) {
+		mei_hdr->length = len;
 		mei_hdr->msg_complete = 1;
-		mei_hdr->reserved = 0;
-		dev_dbg(&dev->pdev->dev, "cb_pos->request_buffer.size =%d"
-			"mei_hdr->msg_complete = %d\n",
-				cb_pos->request_buffer.size,
-				mei_hdr->msg_complete);
-		dev_dbg(&dev->pdev->dev, "cb_pos->information  =%lu\n",
-				cb_pos->information);
-		dev_dbg(&dev->pdev->dev, "mei_hdr->length  =%d\n",
-				mei_hdr->length);
-		*slots -= mei_data2slots(mei_hdr->length);
-		if (mei_write_message(dev, mei_hdr,
-				(unsigned char *)
-				(cb_pos->request_buffer.data +
-				cb_pos->information),
-				mei_hdr->length)) {
-			cl->status = -ENODEV;
-			list_move_tail(&cb_pos->cb_list,
-				&cmpl_list->mei_cb.cb_list);
-			return -ENODEV;
-		} else {
-			if (mei_flow_ctrl_reduce(dev, cl))
-				return -ENODEV;
-			cl->status = 0;
-			cb_pos->information += mei_hdr->length;
-			list_move_tail(&cb_pos->cb_list,
-				&dev->write_waiting_list.mei_cb.cb_list);
-		}
+	/* Split the message only if we can write the whole host buffer */
 	} else if (*slots == dev->hbuf_depth) {
-		/* buffer is still empty */
-		mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
-		mei_hdr->host_addr = cl->host_client_id;
-		mei_hdr->me_addr = cl->me_client_id;
-		mei_hdr->length =
-			(*slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
+		msg_slots = *slots;
+		len = (*slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
+		mei_hdr->length = len;
 		mei_hdr->msg_complete = 0;
-		mei_hdr->reserved = 0;
-		*slots -= mei_data2slots(mei_hdr->length);
-		if (mei_write_message(dev, mei_hdr,
-					(unsigned char *)
-					(cb_pos->request_buffer.data +
-					cb_pos->information),
-					mei_hdr->length)) {
-			cl->status = -ENODEV;
-			list_move_tail(&cb_pos->cb_list,
-				&cmpl_list->mei_cb.cb_list);
-			return -ENODEV;
-		} else {
-			cb_pos->information += mei_hdr->length;
-			dev_dbg(&dev->pdev->dev,
-					"cb_pos->request_buffer.size =%d"
-					" mei_hdr->msg_complete = %d\n",
-					cb_pos->request_buffer.size,
-					mei_hdr->msg_complete);
-			dev_dbg(&dev->pdev->dev, "cb_pos->information  =%lu\n",
-					cb_pos->information);
-			dev_dbg(&dev->pdev->dev, "mei_hdr->length  =%d\n",
-					mei_hdr->length);
-		}
-		return -EMSGSIZE;
 	} else {
-		return -EBADMSG;
+		/* wait for next time the host buffer is empty */
+		return 0;
 	}
 
-	return 0;
-}
-
-/**
- * _mei_irq_thread_cmpl_iamthif - processes completed iamthif operation.
- *
- * @dev: the device structure.
- * @slots: free slots.
- * @cb_pos: callback block.
- * @cl: private data of the file object.
- * @cmpl_list: complete list.
- *
- * returns 0, OK; otherwise, error.
- */
-static int _mei_irq_thread_cmpl_iamthif(struct mei_device *dev, s32 *slots,
-			struct mei_cl_cb *cb_pos,
-			struct mei_cl *cl,
-			struct mei_io_list *cmpl_list)
-{
-	struct mei_msg_hdr *mei_hdr;
-
-	if ((*slots * sizeof(u32)) >= (sizeof(struct mei_msg_hdr) +
-			dev->iamthif_msg_buf_size -
-			dev->iamthif_msg_buf_index)) {
-		mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
-		mei_hdr->host_addr = cl->host_client_id;
-		mei_hdr->me_addr = cl->me_client_id;
-		mei_hdr->length = dev->iamthif_msg_buf_size -
-			dev->iamthif_msg_buf_index;
-		mei_hdr->msg_complete = 1;
-		mei_hdr->reserved = 0;
-
-		*slots -= mei_data2slots(mei_hdr->length);
-
-		if (mei_write_message(dev, mei_hdr,
-					(dev->iamthif_msg_buf +
-					dev->iamthif_msg_buf_index),
-					mei_hdr->length)) {
-			dev->iamthif_state = MEI_IAMTHIF_IDLE;
-			cl->status = -ENODEV;
-			list_del(&cb_pos->cb_list);
-			return -ENODEV;
-		} else {
-			if (mei_flow_ctrl_reduce(dev, cl))
-				return -ENODEV;
-			dev->iamthif_msg_buf_index += mei_hdr->length;
-			cb_pos->information = dev->iamthif_msg_buf_index;
-			cl->status = 0;
-			dev->iamthif_state = MEI_IAMTHIF_FLOW_CONTROL;
-			dev->iamthif_flow_control_pending = true;
-			/* save iamthif cb sent to amthi client */
-			dev->iamthif_current_cb = cb_pos;
-			list_move_tail(&cb_pos->cb_list,
-				&dev->write_waiting_list.mei_cb.cb_list);
+	dev_dbg(&dev->pdev->dev, "buf: size = %d idx = %lu\n",
+			cb->request_buffer.size, cb->buf_idx);
+	dev_dbg(&dev->pdev->dev, "msg: len = %d complete = %d\n",
+			mei_hdr->length, mei_hdr->msg_complete);
 
-		}
-	} else if (*slots == dev->hbuf_depth) {
-		/* buffer is still empty */
-		mei_hdr = (struct mei_msg_hdr *) &dev->wr_msg_buf[0];
-		mei_hdr->host_addr = cl->host_client_id;
-		mei_hdr->me_addr = cl->me_client_id;
-		mei_hdr->length =
-			(*slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
-		mei_hdr->msg_complete = 0;
-		mei_hdr->reserved = 0;
+	*slots -=  msg_slots;
+	if (mei_write_message(dev, mei_hdr,
+		cb->request_buffer.data + cb->buf_idx, len)) {
+		cl->status = -ENODEV;
+		list_move_tail(&cb->list, &cmpl_list->list);
+		return -ENODEV;
+	}
 
-		*slots -= mei_data2slots(mei_hdr->length);
+	if (mei_flow_ctrl_reduce(dev, cl))
+		return -ENODEV;
 
-		if (mei_write_message(dev, mei_hdr,
-					(dev->iamthif_msg_buf +
-					dev->iamthif_msg_buf_index),
-					mei_hdr->length)) {
-			cl->status = -ENODEV;
-			list_del(&cb_pos->cb_list);
-		} else {
-			dev->iamthif_msg_buf_index += mei_hdr->length;
-		}
-		return -EMSGSIZE;
-	} else {
-		return -EBADMSG;
-	}
+	cl->status = 0;
+	cb->buf_idx += mei_hdr->length;
+	if (mei_hdr->msg_complete)
+		list_move_tail(&cb->list, &dev->write_waiting_list.list);
 
 	return 0;
 }
@@ -1067,7 +775,7 @@ static int _mei_irq_thread_cmpl_iamthif(struct mei_device *dev, s32 *slots,
  *
  * returns 0 on success, <0 on failure.
  */
-static int mei_irq_thread_read_handler(struct mei_io_list *cmpl_list,
+static int mei_irq_thread_read_handler(struct mei_cl_cb *cmpl_list,
 		struct mei_device *dev,
 		s32 *slots)
 {
@@ -1130,8 +838,8 @@ static int mei_irq_thread_read_handler(struct mei_io_list *cmpl_list,
 		dev_dbg(&dev->pdev->dev, "call mei_irq_thread_read_iamthif_message.\n");
 		dev_dbg(&dev->pdev->dev, "mei_hdr->length =%d\n",
 				mei_hdr->length);
-		ret = mei_irq_thread_read_amthi_message(cmpl_list,
-							dev, mei_hdr);
+
+		ret = mei_amthif_irq_read_message(cmpl_list, dev, mei_hdr);
 		if (ret)
 			goto end;
 
@@ -1164,53 +872,51 @@ end:
  * mei_irq_thread_write_handler - bottom half write routine after
  * ISR to handle the write processing.
  *
- * @cmpl_list: An instance of our list structure
  * @dev: the device structure
- * @slots: slots to write.
+ * @cmpl_list: An instance of our list structure
  *
  * returns 0 on success, <0 on failure.
  */
-static int mei_irq_thread_write_handler(struct mei_io_list *cmpl_list,
-		struct mei_device *dev,
-		s32 *slots)
+static int mei_irq_thread_write_handler(struct mei_device *dev,
+				struct mei_cl_cb *cmpl_list)
 {
 
 	struct mei_cl *cl;
 	struct mei_cl_cb *pos = NULL, *next = NULL;
-	struct mei_io_list *list;
+	struct mei_cl_cb *list;
+	s32 slots;
 	int ret;
 
 	if (!mei_hbuf_is_empty(dev)) {
 		dev_dbg(&dev->pdev->dev, "host buffer is not empty.\n");
 		return 0;
 	}
-	*slots = mei_hbuf_empty_slots(dev);
-	if (*slots <= 0)
+	slots = mei_hbuf_empty_slots(dev);
+	if (slots <= 0)
 		return -EMSGSIZE;
 
 	/* complete all waiting for write CB */
 	dev_dbg(&dev->pdev->dev, "complete all waiting for write cb.\n");
 
 	list = &dev->write_waiting_list;
-	list_for_each_entry_safe(pos, next, &list->mei_cb.cb_list, cb_list) {
-		cl = (struct mei_cl *)pos->file_private;
+	list_for_each_entry_safe(pos, next, &list->list, list) {
+		cl = pos->cl;
 		if (cl == NULL)
 			continue;
 
 		cl->status = 0;
-		list_del(&pos->cb_list);
+		list_del(&pos->list);
 		if (MEI_WRITING == cl->writing_state &&
-		   (pos->major_file_operations == MEI_WRITE) &&
-		   (cl != &dev->iamthif_cl)) {
+		    pos->fop_type == MEI_FOP_WRITE &&
+		    cl != &dev->iamthif_cl) {
 			dev_dbg(&dev->pdev->dev, "MEI WRITE COMPLETE\n");
 			cl->writing_state = MEI_WRITE_COMPLETE;
-			list_add_tail(&pos->cb_list,
-				      &cmpl_list->mei_cb.cb_list);
+			list_add_tail(&pos->list, &cmpl_list->list);
 		}
 		if (cl == &dev->iamthif_cl) {
 			dev_dbg(&dev->pdev->dev, "check iamthif flow control.\n");
 			if (dev->iamthif_flow_control_pending) {
-				ret = _mei_irq_thread_iamthif_read(dev, slots);
+				ret = mei_amthif_irq_read(dev, &slots);
 				if (ret)
 					return ret;
 			}
@@ -1222,15 +928,11 @@ static int mei_irq_thread_write_handler(struct mei_io_list *cmpl_list,
 		wake_up_interruptible(&dev->wait_stop_wd);
 	}
 
-	if (dev->extra_write_index) {
-		dev_dbg(&dev->pdev->dev, "extra_write_index =%d.\n",
-				dev->extra_write_index);
-		mei_write_message(dev,
-				(struct mei_msg_hdr *) &dev->ext_msg_buf[0],
-				(unsigned char *) &dev->ext_msg_buf[1],
-				(dev->extra_write_index - 1) * sizeof(u32));
-		*slots -= dev->extra_write_index;
-		dev->extra_write_index = 0;
+	if (dev->wr_ext_msg.hdr.length) {
+		mei_write_message(dev, &dev->wr_ext_msg.hdr,
+			dev->wr_ext_msg.data, dev->wr_ext_msg.hdr.length);
+		slots -= mei_data2slots(dev->wr_ext_msg.hdr.length);
+		dev->wr_ext_msg.hdr.length = 0;
 	}
 	if (dev->dev_state == MEI_DEV_ENABLED) {
 		if (dev->wd_pending &&
@@ -1243,41 +945,43 @@ static int mei_irq_thread_write_handler(struct mei_io_list *cmpl_list,
 			dev->wd_pending = false;
 
 			if (dev->wd_state == MEI_WD_RUNNING)
-				*slots -= mei_data2slots(MEI_WD_START_MSG_SIZE);
+				slots -= mei_data2slots(MEI_WD_START_MSG_SIZE);
 			else
-				*slots -= mei_data2slots(MEI_WD_STOP_MSG_SIZE);
+				slots -= mei_data2slots(MEI_WD_STOP_MSG_SIZE);
 		}
 	}
 
 	/* complete control write list CB */
 	dev_dbg(&dev->pdev->dev, "complete control write list cb.\n");
-	list_for_each_entry_safe(pos, next,
-				&dev->ctrl_wr_list.mei_cb.cb_list, cb_list) {
-		cl = (struct mei_cl *) pos->file_private;
+	list_for_each_entry_safe(pos, next, &dev->ctrl_wr_list.list, list) {
+		cl = pos->cl;
 		if (!cl) {
-			list_del(&pos->cb_list);
+			list_del(&pos->list);
 			return -ENODEV;
 		}
-		switch (pos->major_file_operations) {
-		case MEI_CLOSE:
+		switch (pos->fop_type) {
+		case MEI_FOP_CLOSE:
 			/* send disconnect message */
-			ret = _mei_irq_thread_close(dev, slots, pos, cl, cmpl_list);
+			ret = _mei_irq_thread_close(dev, &slots, pos,
+						cl, cmpl_list);
 			if (ret)
 				return ret;
 
 			break;
-		case MEI_READ:
+		case MEI_FOP_READ:
 			/* send flow control message */
-			ret = _mei_irq_thread_read(dev, slots, pos, cl, cmpl_list);
+			ret = _mei_irq_thread_read(dev, &slots, pos,
+						cl, cmpl_list);
 			if (ret)
 				return ret;
 
 			break;
-		case MEI_IOCTL:
+		case MEI_FOP_IOCTL:
 			/* connect message */
 			if (mei_other_client_is_connecting(dev, cl))
 				continue;
-			ret = _mei_irq_thread_ioctl(dev, slots, pos, cl, cmpl_list);
+			ret = _mei_irq_thread_ioctl(dev, &slots, pos,
+						cl, cmpl_list);
 			if (ret)
 				return ret;
 
@@ -1290,40 +994,26 @@ static int mei_irq_thread_write_handler(struct mei_io_list *cmpl_list,
 	}
 	/* complete  write list CB */
 	dev_dbg(&dev->pdev->dev, "complete write list cb.\n");
-	list_for_each_entry_safe(pos, next,
-				&dev->write_list.mei_cb.cb_list, cb_list) {
-		cl = (struct mei_cl *)pos->file_private;
+	list_for_each_entry_safe(pos, next, &dev->write_list.list, list) {
+		cl = pos->cl;
 		if (cl == NULL)
 			continue;
-
-		if (cl != &dev->iamthif_cl) {
-			if (mei_flow_ctrl_creds(dev, cl) <= 0) {
-				dev_dbg(&dev->pdev->dev,
-					"No flow control credentials for client %d, not sending.\n",
-					cl->host_client_id);
-				continue;
-			}
-			ret = _mei_irq_thread_cmpl(dev, slots, pos,
-						cl, cmpl_list);
-			if (ret)
-				return ret;
-
-		} else if (cl == &dev->iamthif_cl) {
-			/* IAMTHIF IOCTL */
-			dev_dbg(&dev->pdev->dev, "complete amthi write cb.\n");
-			if (mei_flow_ctrl_creds(dev, cl) <= 0) {
-				dev_dbg(&dev->pdev->dev,
-					"No flow control credentials for amthi client %d.\n",
-					cl->host_client_id);
-				continue;
-			}
-			ret = _mei_irq_thread_cmpl_iamthif(dev, slots, pos,
-						cl, cmpl_list);
-			if (ret)
-				return ret;
-
+		if (mei_flow_ctrl_creds(dev, cl) <= 0) {
+			dev_dbg(&dev->pdev->dev,
+				"No flow control credentials for client %d, not sending.\n",
+				cl->host_client_id);
+			continue;
 		}
 
+		if (cl == &dev->iamthif_cl)
+			ret = mei_amthif_irq_write_complete(dev, &slots,
+							pos, cmpl_list);
+		else
+			ret = mei_irq_thread_write_complete(dev, &slots, pos,
+						cmpl_list);
+		if (ret)
+			return ret;
+
 	}
 	return 0;
 }
@@ -1342,7 +1032,6 @@ void mei_timer(struct work_struct *work)
 	unsigned long timeout;
 	struct mei_cl *cl_pos = NULL;
 	struct mei_cl *cl_next = NULL;
-	struct list_head *amthi_complete_list = NULL;
 	struct mei_cl_cb  *cb_pos = NULL;
 	struct mei_cl_cb  *cb_next = NULL;
 
@@ -1385,19 +1074,18 @@ void mei_timer(struct work_struct *work)
 			dev->iamthif_state = MEI_IAMTHIF_IDLE;
 			dev->iamthif_timer = 0;
 
-			if (dev->iamthif_current_cb)
-				mei_free_cb_private(dev->iamthif_current_cb);
+			mei_io_cb_free(dev->iamthif_current_cb);
+			dev->iamthif_current_cb = NULL;
 
 			dev->iamthif_file_object = NULL;
-			dev->iamthif_current_cb = NULL;
-			mei_run_next_iamthif_cmd(dev);
+			mei_amthif_run_next_cmd(dev);
 		}
 	}
 
 	if (dev->iamthif_timer) {
 
 		timeout = dev->iamthif_timer +
-				msecs_to_jiffies(IAMTHIF_READ_TIMER);
+			mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
 
 		dev_dbg(&dev->pdev->dev, "dev->iamthif_timer = %ld\n",
 				dev->iamthif_timer);
@@ -1411,25 +1099,22 @@ void mei_timer(struct work_struct *work)
 
 			dev_dbg(&dev->pdev->dev, "freeing AMTHI for other requests\n");
 
-			amthi_complete_list = &dev->amthi_read_complete_list.
-					mei_cb.cb_list;
-
-			list_for_each_entry_safe(cb_pos, cb_next, amthi_complete_list, cb_list) {
+			list_for_each_entry_safe(cb_pos, cb_next,
+				&dev->amthif_rd_complete_list.list, list) {
 
 				cl_pos = cb_pos->file_object->private_data;
 
 				/* Finding the AMTHI entry. */
 				if (cl_pos == &dev->iamthif_cl)
-					list_del(&cb_pos->cb_list);
+					list_del(&cb_pos->list);
 			}
-			if (dev->iamthif_current_cb)
-				mei_free_cb_private(dev->iamthif_current_cb);
+			mei_io_cb_free(dev->iamthif_current_cb);
+			dev->iamthif_current_cb = NULL;
 
 			dev->iamthif_file_object->private_data = NULL;
 			dev->iamthif_file_object = NULL;
-			dev->iamthif_current_cb = NULL;
 			dev->iamthif_timer = 0;
-			mei_run_next_iamthif_cmd(dev);
+			mei_amthif_run_next_cmd(dev);
 
 		}
 	}
@@ -1451,7 +1136,7 @@ out:
 irqreturn_t mei_interrupt_thread_handler(int irq, void *dev_id)
 {
 	struct mei_device *dev = (struct mei_device *) dev_id;
-	struct mei_io_list complete_list;
+	struct mei_cl_cb complete_list;
 	struct mei_cl_cb *cb_pos = NULL, *cb_next = NULL;
 	struct mei_cl *cl;
 	s32 slots;
@@ -1504,17 +1189,17 @@ irqreturn_t mei_interrupt_thread_handler(int irq, void *dev_id)
 	}
 	/* check slots available for reading */
 	slots = mei_count_full_read_slots(dev);
-	dev_dbg(&dev->pdev->dev, "slots =%08x  extra_write_index =%08x.\n",
-		slots, dev->extra_write_index);
-	while (slots > 0 && !dev->extra_write_index) {
-		dev_dbg(&dev->pdev->dev, "slots =%08x  extra_write_index =%08x.\n",
-				slots, dev->extra_write_index);
+	while (slots > 0) {
+		/* we have urgent data to send so break the read */
+		if (dev->wr_ext_msg.hdr.length)
+			break;
+		dev_dbg(&dev->pdev->dev, "slots =%08x\n", slots);
 		dev_dbg(&dev->pdev->dev, "call mei_irq_thread_read_handler.\n");
 		rets = mei_irq_thread_read_handler(&complete_list, dev, &slots);
 		if (rets)
 			goto end;
 	}
-	rets = mei_irq_thread_write_handler(&complete_list, dev, &slots);
+	rets = mei_irq_thread_write_handler(dev, &complete_list);
 end:
 	dev_dbg(&dev->pdev->dev, "end of bottom half function.\n");
 	dev->host_hw_state = mei_hcsr_read(dev);
@@ -1531,21 +1216,20 @@ end:
 		wake_up_interruptible(&dev->wait_recvd_msg);
 		bus_message_received = false;
 	}
-	if (list_empty(&complete_list.mei_cb.cb_list))
+	if (list_empty(&complete_list.list))
 		return IRQ_HANDLED;
 
 
-	list_for_each_entry_safe(cb_pos, cb_next,
-			&complete_list.mei_cb.cb_list, cb_list) {
-		cl = (struct mei_cl *)cb_pos->file_private;
-		list_del(&cb_pos->cb_list);
+	list_for_each_entry_safe(cb_pos, cb_next, &complete_list.list, list) {
+		cl = cb_pos->cl;
+		list_del(&cb_pos->list);
 		if (cl) {
 			if (cl != &dev->iamthif_cl) {
 				dev_dbg(&dev->pdev->dev, "completing call back.\n");
 				_mei_cmpl(cl, cb_pos);
 				cb_pos = NULL;
 			} else if (cl == &dev->iamthif_cl) {
-				_mei_cmpl_iamthif(dev, cb_pos);
+				mei_amthif_complete(dev, cb_pos);
 			}
 		}
 	}
diff --git a/drivers/misc/mei/iorw.c b/drivers/misc/mei/iorw.c
index fcba98eb892e..eb93a1b53b9b 100644
--- a/drivers/misc/mei/iorw.c
+++ b/drivers/misc/mei/iorw.c
@@ -39,6 +39,95 @@
 #include "interface.h"
 
 /**
+ * mei_io_cb_free - free mei_cb_private related memory
+ *
+ * @cb: mei callback struct
+ */
+void mei_io_cb_free(struct mei_cl_cb *cb)
+{
+	if (cb == NULL)
+		return;
+
+	kfree(cb->request_buffer.data);
+	kfree(cb->response_buffer.data);
+	kfree(cb);
+}
+/**
+ * mei_io_cb_init - allocate and initialize io callback
+ *
+ * @cl - mei client
+ * @file: pointer to file structure
+ *
+ * returns mei_cl_cb pointer or NULL;
+ */
+struct mei_cl_cb *mei_io_cb_init(struct mei_cl *cl, struct file *fp)
+{
+	struct mei_cl_cb *cb;
+
+	cb = kzalloc(sizeof(struct mei_cl_cb), GFP_KERNEL);
+	if (!cb)
+		return NULL;
+
+	mei_io_list_init(cb);
+
+	cb->file_object = fp;
+	cb->cl = cl;
+	cb->buf_idx = 0;
+	return cb;
+}
+
+
+/**
+ * mei_io_cb_alloc_req_buf - allocate request buffer
+ *
+ * @cb -  io callback structure
+ * @size: size of the buffer
+ *
+ * returns 0 on success
+ *         -EINVAL if cb is NULL
+ *         -ENOMEM if allocation failed
+ */
+int mei_io_cb_alloc_req_buf(struct mei_cl_cb *cb, size_t length)
+{
+	if (!cb)
+		return -EINVAL;
+
+	if (length == 0)
+		return 0;
+
+	cb->request_buffer.data = kmalloc(length, GFP_KERNEL);
+	if (!cb->request_buffer.data)
+		return -ENOMEM;
+	cb->request_buffer.size = length;
+	return 0;
+}
+/**
+ * mei_io_cb_alloc_req_buf - allocate respose buffer
+ *
+ * @cb -  io callback structure
+ * @size: size of the buffer
+ *
+ * returns 0 on success
+ *         -EINVAL if cb is NULL
+ *         -ENOMEM if allocation failed
+ */
+int mei_io_cb_alloc_resp_buf(struct mei_cl_cb *cb, size_t length)
+{
+	if (!cb)
+		return -EINVAL;
+
+	if (length == 0)
+		return 0;
+
+	cb->response_buffer.data = kmalloc(length, GFP_KERNEL);
+	if (!cb->response_buffer.data)
+		return -ENOMEM;
+	cb->response_buffer.size = length;
+	return 0;
+}
+
+
+/**
  * mei_me_cl_by_id return index to me_clients for client_id
  *
  * @dev: the device structure
@@ -82,9 +171,7 @@ int mei_ioctl_connect_client(struct file *file,
 	struct mei_cl_cb *cb;
 	struct mei_client *client;
 	struct mei_cl *cl;
-	struct mei_cl *cl_pos = NULL;
-	struct mei_cl *cl_next = NULL;
-	long timeout = CONNECT_TIMEOUT;
+	long timeout = mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT);
 	int i;
 	int err;
 	int rets;
@@ -97,16 +184,14 @@ int mei_ioctl_connect_client(struct file *file,
 
 	dev_dbg(&dev->pdev->dev, "mei_ioctl_connect_client() Entry\n");
 
-
 	/* buffered ioctl cb */
-	cb = kzalloc(sizeof(struct mei_cl_cb), GFP_KERNEL);
+	cb = mei_io_cb_init(cl, file);
 	if (!cb) {
 		rets = -ENOMEM;
 		goto end;
 	}
-	INIT_LIST_HEAD(&cb->cb_list);
 
-	cb->major_file_operations = MEI_IOCTL;
+	cb->fop_type = MEI_FOP_IOCTL;
 
 	if (dev->dev_state != MEI_DEV_ENABLED) {
 		rets = -ENODEV;
@@ -142,21 +227,9 @@ int mei_ioctl_connect_client(struct file *file,
 			goto end;
 		}
 		clear_bit(cl->host_client_id, dev->host_clients_map);
-		list_for_each_entry_safe(cl_pos, cl_next,
-					 &dev->file_list, link) {
-			if (mei_cl_cmp_id(cl, cl_pos)) {
-				dev_dbg(&dev->pdev->dev,
-					"remove file private data node host"
-				    " client = %d, ME client = %d.\n",
-				    cl_pos->host_client_id,
-				    cl_pos->me_client_id);
-				list_del(&cl_pos->link);
-			}
+		mei_me_cl_unlink(dev, cl);
 
-		}
-		dev_dbg(&dev->pdev->dev, "free file private data memory.\n");
 		kfree(cl);
-
 		cl = NULL;
 		file->private_data = &dev->iamthif_cl;
 
@@ -192,25 +265,19 @@ int mei_ioctl_connect_client(struct file *file,
 		} else {
 			dev_dbg(&dev->pdev->dev, "Sending connect message - succeeded\n");
 			cl->timer_count = MEI_CONNECT_TIMEOUT;
-			cb->file_private = cl;
-			list_add_tail(&cb->cb_list,
-				      &dev->ctrl_rd_list.mei_cb.
-				      cb_list);
+			list_add_tail(&cb->list, &dev->ctrl_rd_list.list);
 		}
 
 
 	} else {
 		dev_dbg(&dev->pdev->dev, "Queuing the connect request due to device busy\n");
-		cb->file_private = cl;
 		dev_dbg(&dev->pdev->dev, "add connect cb to control write list.\n");
-		list_add_tail(&cb->cb_list,
-			      &dev->ctrl_wr_list.mei_cb.cb_list);
+		list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
 	}
 	mutex_unlock(&dev->device_lock);
 	err = wait_event_timeout(dev->wait_recvd_msg,
 			(MEI_FILE_CONNECTED == cl->state ||
-			 MEI_FILE_DISCONNECTED == cl->state),
-			timeout * HZ);
+			 MEI_FILE_DISCONNECTED == cl->state), timeout);
 
 	mutex_lock(&dev->device_lock);
 	if (MEI_FILE_CONNECTED == cl->state) {
@@ -234,153 +301,7 @@ int mei_ioctl_connect_client(struct file *file,
 	rets = 0;
 end:
 	dev_dbg(&dev->pdev->dev, "free connect cb memory.");
-	kfree(cb);
-	return rets;
-}
-
-/**
- * find_amthi_read_list_entry - finds a amthilist entry for current file
- *
- * @dev: the device structure
- * @file: pointer to file object
- *
- * returns   returned a list entry on success, NULL on failure.
- */
-struct mei_cl_cb *find_amthi_read_list_entry(
-		struct mei_device *dev,
-		struct file *file)
-{
-	struct mei_cl *cl_temp;
-	struct mei_cl_cb *pos = NULL;
-	struct mei_cl_cb *next = NULL;
-
-	list_for_each_entry_safe(pos, next,
-	    &dev->amthi_read_complete_list.mei_cb.cb_list, cb_list) {
-		cl_temp = (struct mei_cl *)pos->file_private;
-		if (cl_temp && cl_temp == &dev->iamthif_cl &&
-			pos->file_object == file)
-			return pos;
-	}
-	return NULL;
-}
-
-/**
- * amthi_read - read data from AMTHI client
- *
- * @dev: the device structure
- * @if_num:  minor number
- * @file: pointer to file object
- * @*ubuf: pointer to user data in user space
- * @length: data length to read
- * @offset: data read offset
- *
- * Locking: called under "dev->device_lock" lock
- *
- * returns
- *  returned data length on success,
- *  zero if no data to read,
- *  negative on failure.
- */
-int amthi_read(struct mei_device *dev, struct file *file,
-	       char __user *ubuf, size_t length, loff_t *offset)
-{
-	int rets;
-	int wait_ret;
-	struct mei_cl_cb *cb = NULL;
-	struct mei_cl *cl = file->private_data;
-	unsigned long timeout;
-	int i;
-
-	/* Only Posible if we are in timeout */
-	if (!cl || cl != &dev->iamthif_cl) {
-		dev_dbg(&dev->pdev->dev, "bad file ext.\n");
-		return -ETIMEDOUT;
-	}
-
-	i = mei_me_cl_by_id(dev, dev->iamthif_cl.me_client_id);
-
-	if (i < 0) {
-		dev_dbg(&dev->pdev->dev, "amthi client not found.\n");
-		return -ENODEV;
-	}
-	dev_dbg(&dev->pdev->dev, "checking amthi data\n");
-	cb = find_amthi_read_list_entry(dev, file);
-
-	/* Check for if we can block or not*/
-	if (cb == NULL && file->f_flags & O_NONBLOCK)
-		return -EAGAIN;
-
-
-	dev_dbg(&dev->pdev->dev, "waiting for amthi data\n");
-	while (cb == NULL) {
-		/* unlock the Mutex */
-		mutex_unlock(&dev->device_lock);
-
-		wait_ret = wait_event_interruptible(dev->iamthif_cl.wait,
-			(cb = find_amthi_read_list_entry(dev, file)));
-
-		if (wait_ret)
-			return -ERESTARTSYS;
-
-		dev_dbg(&dev->pdev->dev, "woke up from sleep\n");
-
-		/* Locking again the Mutex */
-		mutex_lock(&dev->device_lock);
-	}
-
-
-	dev_dbg(&dev->pdev->dev, "Got amthi data\n");
-	dev->iamthif_timer = 0;
-
-	if (cb) {
-		timeout = cb->read_time + msecs_to_jiffies(IAMTHIF_READ_TIMER);
-		dev_dbg(&dev->pdev->dev, "amthi timeout = %lud\n",
-				timeout);
-
-		if  (time_after(jiffies, timeout)) {
-			dev_dbg(&dev->pdev->dev, "amthi Time out\n");
-			/* 15 sec for the message has expired */
-			list_del(&cb->cb_list);
-			rets = -ETIMEDOUT;
-			goto free;
-		}
-	}
-	/* if the whole message will fit remove it from the list */
-	if (cb->information >= *offset && length >= (cb->information - *offset))
-		list_del(&cb->cb_list);
-	else if (cb->information > 0 && cb->information <= *offset) {
-		/* end of the message has been reached */
-		list_del(&cb->cb_list);
-		rets = 0;
-		goto free;
-	}
-		/* else means that not full buffer will be read and do not
-		 * remove message from deletion list
-		 */
-
-	dev_dbg(&dev->pdev->dev, "amthi cb->response_buffer size - %d\n",
-	    cb->response_buffer.size);
-	dev_dbg(&dev->pdev->dev, "amthi cb->information - %lu\n",
-	    cb->information);
-
-	/* length is being turncated to PAGE_SIZE, however,
-	 * the information may be longer */
-	length = min_t(size_t, length, (cb->information - *offset));
-
-	if (copy_to_user(ubuf, cb->response_buffer.data + *offset, length))
-		rets = -EFAULT;
-	else {
-		rets = length;
-		if ((*offset + length) < cb->information) {
-			*offset += length;
-			goto out;
-		}
-	}
-free:
-	dev_dbg(&dev->pdev->dev, "free amthi cb memory.\n");
-	*offset = 0;
-	mei_free_cb_private(cb);
-out:
+	mei_io_cb_free(cb);
 	return rets;
 }
 
@@ -396,7 +317,7 @@ out:
 int mei_start_read(struct mei_device *dev, struct mei_cl *cl)
 {
 	struct mei_cl_cb *cb;
-	int rets = 0;
+	int rets;
 	int i;
 
 	if (cl->state != MEI_FILE_CONNECTED)
@@ -405,187 +326,41 @@ int mei_start_read(struct mei_device *dev, struct mei_cl *cl)
 	if (dev->dev_state != MEI_DEV_ENABLED)
 		return -ENODEV;
 
-	dev_dbg(&dev->pdev->dev, "check if read is pending.\n");
 	if (cl->read_pending || cl->read_cb) {
 		dev_dbg(&dev->pdev->dev, "read is pending.\n");
 		return -EBUSY;
 	}
+	i = mei_me_cl_by_id(dev, cl->me_client_id);
+	if (i < 0) {
+		dev_err(&dev->pdev->dev, "no such me client %d\n",
+			cl->me_client_id);
+		return  -ENODEV;
+	}
 
-	cb = kzalloc(sizeof(struct mei_cl_cb), GFP_KERNEL);
+	cb = mei_io_cb_init(cl, NULL);
 	if (!cb)
 		return -ENOMEM;
 
-	dev_dbg(&dev->pdev->dev, "allocation call back successful. host client = %d, ME client = %d\n",
-		cl->host_client_id, cl->me_client_id);
-	i = mei_me_cl_by_id(dev, cl->me_client_id);
-	if (i < 0) {
-		rets = -ENODEV;
-		goto unlock;
-	}
+	rets = mei_io_cb_alloc_resp_buf(cb,
+			dev->me_clients[i].props.max_msg_length);
+	if (rets)
+		goto err;
 
-	cb->response_buffer.size = dev->me_clients[i].props.max_msg_length;
-	cb->response_buffer.data =
-			kmalloc(cb->response_buffer.size, GFP_KERNEL);
-	if (!cb->response_buffer.data) {
-		rets = -ENOMEM;
-		goto unlock;
-	}
-	dev_dbg(&dev->pdev->dev, "allocation call back data success.\n");
-	cb->major_file_operations = MEI_READ;
-	/* make sure information is zero before we start */
-	cb->information = 0;
-	cb->file_private = (void *) cl;
+	cb->fop_type = MEI_FOP_READ;
 	cl->read_cb = cb;
 	if (dev->mei_host_buffer_is_empty) {
 		dev->mei_host_buffer_is_empty = false;
 		if (mei_send_flow_control(dev, cl)) {
 			rets = -ENODEV;
-			goto unlock;
+			goto err;
 		}
-		list_add_tail(&cb->cb_list, &dev->read_list.mei_cb.cb_list);
+		list_add_tail(&cb->list, &dev->read_list.list);
 	} else {
-		list_add_tail(&cb->cb_list, &dev->ctrl_wr_list.mei_cb.cb_list);
+		list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
 	}
 	return rets;
-unlock:
-	mei_free_cb_private(cb);
+err:
+	mei_io_cb_free(cb);
 	return rets;
 }
 
-/**
- * amthi_write - write iamthif data to amthi client
- *
- * @dev: the device structure
- * @cb: mei call back struct
- *
- * returns 0 on success, <0 on failure.
- */
-int amthi_write(struct mei_device *dev, struct mei_cl_cb *cb)
-{
-	struct mei_msg_hdr mei_hdr;
-	int ret;
-
-	if (!dev || !cb)
-		return -ENODEV;
-
-	dev_dbg(&dev->pdev->dev, "write data to amthi client.\n");
-
-	dev->iamthif_state = MEI_IAMTHIF_WRITING;
-	dev->iamthif_current_cb = cb;
-	dev->iamthif_file_object = cb->file_object;
-	dev->iamthif_canceled = false;
-	dev->iamthif_ioctl = true;
-	dev->iamthif_msg_buf_size = cb->request_buffer.size;
-	memcpy(dev->iamthif_msg_buf, cb->request_buffer.data,
-	       cb->request_buffer.size);
-
-	ret = mei_flow_ctrl_creds(dev, &dev->iamthif_cl);
-	if (ret < 0)
-		return ret;
-
-	if (ret && dev->mei_host_buffer_is_empty) {
-		ret = 0;
-		dev->mei_host_buffer_is_empty = false;
-		if (cb->request_buffer.size > mei_hbuf_max_data(dev)) {
-			mei_hdr.length = mei_hbuf_max_data(dev);
-			mei_hdr.msg_complete = 0;
-		} else {
-			mei_hdr.length = cb->request_buffer.size;
-			mei_hdr.msg_complete = 1;
-		}
-
-		mei_hdr.host_addr = dev->iamthif_cl.host_client_id;
-		mei_hdr.me_addr = dev->iamthif_cl.me_client_id;
-		mei_hdr.reserved = 0;
-		dev->iamthif_msg_buf_index += mei_hdr.length;
-		if (mei_write_message(dev, &mei_hdr,
-					(unsigned char *)(dev->iamthif_msg_buf),
-					mei_hdr.length))
-			return -ENODEV;
-
-		if (mei_hdr.msg_complete) {
-			if (mei_flow_ctrl_reduce(dev, &dev->iamthif_cl))
-				return -ENODEV;
-			dev->iamthif_flow_control_pending = true;
-			dev->iamthif_state = MEI_IAMTHIF_FLOW_CONTROL;
-			dev_dbg(&dev->pdev->dev, "add amthi cb to write waiting list\n");
-			dev->iamthif_current_cb = cb;
-			dev->iamthif_file_object = cb->file_object;
-			list_add_tail(&cb->cb_list,
-				      &dev->write_waiting_list.mei_cb.cb_list);
-		} else {
-			dev_dbg(&dev->pdev->dev, "message does not complete, "
-					"so add amthi cb to write list.\n");
-			list_add_tail(&cb->cb_list,
-				      &dev->write_list.mei_cb.cb_list);
-		}
-	} else {
-		if (!(dev->mei_host_buffer_is_empty))
-			dev_dbg(&dev->pdev->dev, "host buffer is not empty");
-
-		dev_dbg(&dev->pdev->dev, "No flow control credentials, "
-				"so add iamthif cb to write list.\n");
-		list_add_tail(&cb->cb_list, &dev->write_list.mei_cb.cb_list);
-	}
-	return 0;
-}
-
-/**
- * iamthif_ioctl_send_msg - send cmd data to amthi client
- *
- * @dev: the device structure
- *
- * returns 0 on success, <0 on failure.
- */
-void mei_run_next_iamthif_cmd(struct mei_device *dev)
-{
-	struct mei_cl *cl_tmp;
-	struct mei_cl_cb *pos = NULL;
-	struct mei_cl_cb *next = NULL;
-	int status;
-
-	if (!dev)
-		return;
-
-	dev->iamthif_msg_buf_size = 0;
-	dev->iamthif_msg_buf_index = 0;
-	dev->iamthif_canceled = false;
-	dev->iamthif_ioctl = true;
-	dev->iamthif_state = MEI_IAMTHIF_IDLE;
-	dev->iamthif_timer = 0;
-	dev->iamthif_file_object = NULL;
-
-	dev_dbg(&dev->pdev->dev, "complete amthi cmd_list cb.\n");
-
-	list_for_each_entry_safe(pos, next,
-			&dev->amthi_cmd_list.mei_cb.cb_list, cb_list) {
-		list_del(&pos->cb_list);
-		cl_tmp = (struct mei_cl *)pos->file_private;
-
-		if (cl_tmp && cl_tmp == &dev->iamthif_cl) {
-			status = amthi_write(dev, pos);
-			if (status) {
-				dev_dbg(&dev->pdev->dev,
-					"amthi write failed status = %d\n",
-						status);
-				return;
-			}
-			break;
-		}
-	}
-}
-
-/**
- * mei_free_cb_private - free mei_cb_private related memory
- *
- * @cb: mei callback struct
- */
-void mei_free_cb_private(struct mei_cl_cb *cb)
-{
-	if (cb == NULL)
-		return;
-
-	kfree(cb->request_buffer.data);
-	kfree(cb->response_buffer.data);
-	kfree(cb);
-}
diff --git a/drivers/misc/mei/main.c b/drivers/misc/mei/main.c
index e8b0858132c1..43fb52ff98ad 100644
--- a/drivers/misc/mei/main.c
+++ b/drivers/misc/mei/main.c
@@ -90,93 +90,6 @@ static DEFINE_MUTEX(mei_mutex);
 
 
 /**
- * mei_clear_list - removes all callbacks associated with file
- *		from mei_cb_list
- *
- * @dev: device structure.
- * @file: file structure
- * @mei_cb_list: callbacks list
- *
- * mei_clear_list is called to clear resources associated with file
- * when application calls close function or Ctrl-C was pressed
- *
- * returns true if callback removed from the list, false otherwise
- */
-static bool mei_clear_list(struct mei_device *dev,
-		struct file *file, struct list_head *mei_cb_list)
-{
-	struct mei_cl_cb *cb_pos = NULL;
-	struct mei_cl_cb *cb_next = NULL;
-	struct file *file_temp;
-	bool removed = false;
-
-	/* list all list member */
-	list_for_each_entry_safe(cb_pos, cb_next, mei_cb_list, cb_list) {
-		file_temp = (struct file *)cb_pos->file_object;
-		/* check if list member associated with a file */
-		if (file_temp == file) {
-			/* remove member from the list */
-			list_del(&cb_pos->cb_list);
-			/* check if cb equal to current iamthif cb */
-			if (dev->iamthif_current_cb == cb_pos) {
-				dev->iamthif_current_cb = NULL;
-				/* send flow control to iamthif client */
-				mei_send_flow_control(dev, &dev->iamthif_cl);
-			}
-			/* free all allocated buffers */
-			mei_free_cb_private(cb_pos);
-			cb_pos = NULL;
-			removed = true;
-		}
-	}
-	return removed;
-}
-
-/**
- * mei_clear_lists - removes all callbacks associated with file
- *
- * @dev: device structure
- * @file: file structure
- *
- * mei_clear_lists is called to clear resources associated with file
- * when application calls close function or Ctrl-C was pressed
- *
- * returns true if callback removed from the list, false otherwise
- */
-static bool mei_clear_lists(struct mei_device *dev, struct file *file)
-{
-	bool removed = false;
-
-	/* remove callbacks associated with a file */
-	mei_clear_list(dev, file, &dev->amthi_cmd_list.mei_cb.cb_list);
-	if (mei_clear_list(dev, file,
-			    &dev->amthi_read_complete_list.mei_cb.cb_list))
-		removed = true;
-
-	mei_clear_list(dev, file, &dev->ctrl_rd_list.mei_cb.cb_list);
-
-	if (mei_clear_list(dev, file, &dev->ctrl_wr_list.mei_cb.cb_list))
-		removed = true;
-
-	if (mei_clear_list(dev, file, &dev->write_waiting_list.mei_cb.cb_list))
-		removed = true;
-
-	if (mei_clear_list(dev, file, &dev->write_list.mei_cb.cb_list))
-		removed = true;
-
-	/* check if iamthif_current_cb not NULL */
-	if (dev->iamthif_current_cb && !removed) {
-		/* check file and iamthif current cb association */
-		if (dev->iamthif_current_cb->file_object == file) {
-			/* remove cb */
-			mei_free_cb_private(dev->iamthif_current_cb);
-			dev->iamthif_current_cb = NULL;
-			removed = true;
-		}
-	}
-	return removed;
-}
-/**
  * find_read_list_entry - find read list entry
  *
  * @dev: device structure
@@ -192,14 +105,9 @@ static struct mei_cl_cb *find_read_list_entry(
 	struct mei_cl_cb *next = NULL;
 
 	dev_dbg(&dev->pdev->dev, "remove read_list CB\n");
-	list_for_each_entry_safe(pos, next,
-			&dev->read_list.mei_cb.cb_list, cb_list) {
-		struct mei_cl *cl_temp;
-		cl_temp = (struct mei_cl *)pos->file_private;
-
-		if (mei_cl_cmp_id(cl, cl_temp))
+	list_for_each_entry_safe(pos, next, &dev->read_list.list, list)
+		if (mei_cl_cmp_id(cl, pos->cl))
 			return pos;
-	}
 	return NULL;
 }
 
@@ -297,67 +205,51 @@ static int mei_release(struct inode *inode, struct file *file)
 	dev = cl->dev;
 
 	mutex_lock(&dev->device_lock);
-	if (cl != &dev->iamthif_cl) {
-		if (cl->state == MEI_FILE_CONNECTED) {
-			cl->state = MEI_FILE_DISCONNECTING;
-			dev_dbg(&dev->pdev->dev,
-				"disconnecting client host client = %d, "
-			    "ME client = %d\n",
-			    cl->host_client_id,
-			    cl->me_client_id);
-			rets = mei_disconnect_host_client(dev, cl);
-		}
-		mei_cl_flush_queues(cl);
-		dev_dbg(&dev->pdev->dev, "remove client host client = %d, ME client = %d\n",
+	if (cl == &dev->iamthif_cl) {
+		rets = mei_amthif_release(dev, file);
+		goto out;
+	}
+	if (cl->state == MEI_FILE_CONNECTED) {
+		cl->state = MEI_FILE_DISCONNECTING;
+		dev_dbg(&dev->pdev->dev,
+			"disconnecting client host client = %d, "
+		    "ME client = %d\n",
 		    cl->host_client_id,
 		    cl->me_client_id);
+		rets = mei_disconnect_host_client(dev, cl);
+	}
+	mei_cl_flush_queues(cl);
+	dev_dbg(&dev->pdev->dev, "remove client host client = %d, ME client = %d\n",
+	    cl->host_client_id,
+	    cl->me_client_id);
+
+	if (dev->open_handle_count > 0) {
+		clear_bit(cl->host_client_id, dev->host_clients_map);
+		dev->open_handle_count--;
+	}
+	mei_me_cl_unlink(dev, cl);
 
-		if (dev->open_handle_count > 0) {
-			clear_bit(cl->host_client_id, dev->host_clients_map);
-			dev->open_handle_count--;
-		}
-		mei_remove_client_from_file_list(dev, cl->host_client_id);
-
-		/* free read cb */
-		cb = NULL;
-		if (cl->read_cb) {
-			cb = find_read_list_entry(dev, cl);
-			/* Remove entry from read list */
-			if (cb)
-				list_del(&cb->cb_list);
-
-			cb = cl->read_cb;
-			cl->read_cb = NULL;
-		}
-
-		file->private_data = NULL;
-
-		if (cb) {
-			mei_free_cb_private(cb);
-			cb = NULL;
-		}
+	/* free read cb */
+	cb = NULL;
+	if (cl->read_cb) {
+		cb = find_read_list_entry(dev, cl);
+		/* Remove entry from read list */
+		if (cb)
+			list_del(&cb->list);
 
-		kfree(cl);
-	} else {
-		if (dev->open_handle_count > 0)
-			dev->open_handle_count--;
-
-		if (dev->iamthif_file_object == file &&
-		    dev->iamthif_state != MEI_IAMTHIF_IDLE) {
-
-			dev_dbg(&dev->pdev->dev, "amthi canceled iamthif state %d\n",
-			    dev->iamthif_state);
-			dev->iamthif_canceled = true;
-			if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE) {
-				dev_dbg(&dev->pdev->dev, "run next amthi iamthif cb\n");
-				mei_run_next_iamthif_cmd(dev);
-			}
-		}
+		cb = cl->read_cb;
+		cl->read_cb = NULL;
+	}
 
-		if (mei_clear_lists(dev, file))
-			dev->iamthif_state = MEI_IAMTHIF_IDLE;
+	file->private_data = NULL;
 
+	if (cb) {
+		mei_io_cb_free(cb);
+		cb = NULL;
 	}
+
+	kfree(cl);
+out:
 	mutex_unlock(&dev->device_lock);
 	return rets;
 }
@@ -411,20 +303,19 @@ static ssize_t mei_read(struct file *file, char __user *ubuf,
 	}
 
 	if (cl == &dev->iamthif_cl) {
-		rets = amthi_read(dev, file, ubuf, length, offset);
+		rets = mei_amthif_read(dev, file, ubuf, length, offset);
 		goto out;
 	}
 
-	if (cl->read_cb && cl->read_cb->information > *offset) {
+	if (cl->read_cb && cl->read_cb->buf_idx > *offset) {
 		cb = cl->read_cb;
 		goto copy_buffer;
-	} else if (cl->read_cb && cl->read_cb->information > 0 &&
-		   cl->read_cb->information <= *offset) {
+	} else if (cl->read_cb && cl->read_cb->buf_idx > 0 &&
+		   cl->read_cb->buf_idx <= *offset) {
 		cb = cl->read_cb;
 		rets = 0;
 		goto free;
-	} else if ((!cl->read_cb || !cl->read_cb->information) &&
-		    *offset > 0) {
+	} else if ((!cl->read_cb || !cl->read_cb->buf_idx) && *offset > 0) {
 		/*Offset needs to be cleaned for contiguous reads*/
 		*offset = 0;
 		rets = 0;
@@ -481,16 +372,15 @@ static ssize_t mei_read(struct file *file, char __user *ubuf,
 copy_buffer:
 	dev_dbg(&dev->pdev->dev, "cb->response_buffer size - %d\n",
 	    cb->response_buffer.size);
-	dev_dbg(&dev->pdev->dev, "cb->information - %lu\n",
-	    cb->information);
-	if (length == 0 || ubuf == NULL || *offset > cb->information) {
+	dev_dbg(&dev->pdev->dev, "cb->buf_idx - %lu\n", cb->buf_idx);
+	if (length == 0 || ubuf == NULL || *offset > cb->buf_idx) {
 		rets = -EMSGSIZE;
 		goto free;
 	}
 
-	/* length is being truncated to PAGE_SIZE, however, */
-	/* information size may be longer */
-	length = min_t(size_t, length, (cb->information - *offset));
+	/* length is being truncated to PAGE_SIZE,
+	 * however buf_idx may point beyond that */
+	length = min_t(size_t, length, cb->buf_idx - *offset);
 
 	if (copy_to_user(ubuf, cb->response_buffer.data + *offset, length)) {
 		rets = -EFAULT;
@@ -499,15 +389,15 @@ copy_buffer:
 
 	rets = length;
 	*offset += length;
-	if ((unsigned long)*offset < cb->information)
+	if ((unsigned long)*offset < cb->buf_idx)
 		goto out;
 
 free:
 	cb_pos = find_read_list_entry(dev, cl);
 	/* Remove entry from read list */
 	if (cb_pos)
-		list_del(&cb_pos->cb_list);
-	mei_free_cb_private(cb);
+		list_del(&cb_pos->list);
+	mei_io_cb_free(cb);
 	cl->reading_state = MEI_IDLE;
 	cl->read_cb = NULL;
 	cl->read_pending = 0;
@@ -516,7 +406,6 @@ out:
 	mutex_unlock(&dev->device_lock);
 	return rets;
 }
-
 /**
  * mei_write - the write function.
  *
@@ -546,23 +435,39 @@ static ssize_t mei_write(struct file *file, const char __user *ubuf,
 	mutex_lock(&dev->device_lock);
 
 	if (dev->dev_state != MEI_DEV_ENABLED) {
-		mutex_unlock(&dev->device_lock);
-		return -ENODEV;
+		rets = -ENODEV;
+		goto err;
 	}
 
+	i = mei_me_cl_by_id(dev, cl->me_client_id);
+	if (i < 0) {
+		rets = -ENODEV;
+		goto err;
+	}
+	if (length > dev->me_clients[i].props.max_msg_length || length <= 0) {
+		rets = -EMSGSIZE;
+		goto err;
+	}
+
+	if (cl->state != MEI_FILE_CONNECTED) {
+		rets = -ENODEV;
+		dev_err(&dev->pdev->dev, "host client = %d,  is not connected to ME client = %d",
+			cl->host_client_id, cl->me_client_id);
+		goto err;
+	}
 	if (cl == &dev->iamthif_cl) {
-		write_cb = find_amthi_read_list_entry(dev, file);
+		write_cb = mei_amthif_find_read_list_entry(dev, file);
 
 		if (write_cb) {
 			timeout = write_cb->read_time +
-					msecs_to_jiffies(IAMTHIF_READ_TIMER);
+				mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
 
 			if (time_after(jiffies, timeout) ||
-				 cl->reading_state == MEI_READ_COMPLETE) {
-					*offset = 0;
-					list_del(&write_cb->cb_list);
-					mei_free_cb_private(write_cb);
-					write_cb = NULL;
+			    cl->reading_state == MEI_READ_COMPLETE) {
+				*offset = 0;
+				list_del(&write_cb->list);
+				mei_io_cb_free(write_cb);
+				write_cb = NULL;
 			}
 		}
 	}
@@ -572,8 +477,8 @@ static ssize_t mei_write(struct file *file, const char __user *ubuf,
 		*offset = 0;
 		write_cb = find_read_list_entry(dev, cl);
 		if (write_cb) {
-			list_del(&write_cb->cb_list);
-			mei_free_cb_private(write_cb);
+			list_del(&write_cb->list);
+			mei_io_cb_free(write_cb);
 			write_cb = NULL;
 			cl->reading_state = MEI_IDLE;
 			cl->read_cb = NULL;
@@ -583,24 +488,21 @@ static ssize_t mei_write(struct file *file, const char __user *ubuf,
 		*offset = 0;
 
 
-	write_cb = kzalloc(sizeof(struct mei_cl_cb), GFP_KERNEL);
+	write_cb = mei_io_cb_init(cl, file);
 	if (!write_cb) {
-		mutex_unlock(&dev->device_lock);
-		return -ENOMEM;
+		dev_err(&dev->pdev->dev, "write cb allocation failed\n");
+		rets = -ENOMEM;
+		goto err;
 	}
+	rets = mei_io_cb_alloc_req_buf(write_cb, length);
+	if (rets)
+		goto err;
 
-	write_cb->file_object = file;
-	write_cb->file_private = cl;
-	write_cb->request_buffer.data = kmalloc(length, GFP_KERNEL);
-	rets = -ENOMEM;
-	if (!write_cb->request_buffer.data)
-		goto unlock_dev;
-
-	dev_dbg(&dev->pdev->dev, "length =%d\n", (int) length);
+	dev_dbg(&dev->pdev->dev, "cb request size = %zd\n", length);
 
-	rets = -EFAULT;
-	if (copy_from_user(write_cb->request_buffer.data, ubuf, length))
-		goto unlock_dev;
+	rets = copy_from_user(write_cb->request_buffer.data, ubuf, length);
+	if (rets)
+		goto err;
 
 	cl->sm_state = 0;
 	if (length == 4 &&
@@ -612,139 +514,71 @@ static ssize_t mei_write(struct file *file, const char __user *ubuf,
 				 write_cb->request_buffer.data, 4) == 0)))
 		cl->sm_state |= MEI_WD_STATE_INDEPENDENCE_MSG_SENT;
 
-	INIT_LIST_HEAD(&write_cb->cb_list);
 	if (cl == &dev->iamthif_cl) {
-		write_cb->response_buffer.data =
-		    kmalloc(dev->iamthif_mtu, GFP_KERNEL);
-		if (!write_cb->response_buffer.data) {
-			rets = -ENOMEM;
-			goto unlock_dev;
-		}
-		if (dev->dev_state != MEI_DEV_ENABLED) {
-			rets = -ENODEV;
-			goto unlock_dev;
-		}
-		i = mei_me_cl_by_id(dev, dev->iamthif_cl.me_client_id);
-		if (i < 0) {
-			rets = -ENODEV;
-			goto unlock_dev;
-		}
-		if (length > dev->me_clients[i].props.max_msg_length ||
-			   length <= 0) {
-			rets = -EMSGSIZE;
-			goto unlock_dev;
-		}
+		rets = mei_amthif_write(dev, write_cb);
 
-		write_cb->response_buffer.size = dev->iamthif_mtu;
-		write_cb->major_file_operations = MEI_IOCTL;
-		write_cb->information = 0;
-		write_cb->request_buffer.size = length;
-		if (dev->iamthif_cl.state != MEI_FILE_CONNECTED) {
-			rets = -ENODEV;
-			goto unlock_dev;
-		}
-
-		if (!list_empty(&dev->amthi_cmd_list.mei_cb.cb_list) ||
-				dev->iamthif_state != MEI_IAMTHIF_IDLE) {
-			dev_dbg(&dev->pdev->dev, "amthi_state = %d\n",
-					(int) dev->iamthif_state);
-			dev_dbg(&dev->pdev->dev, "add amthi cb to amthi cmd waiting list\n");
-			list_add_tail(&write_cb->cb_list,
-					&dev->amthi_cmd_list.mei_cb.cb_list);
-			rets = length;
-		} else {
-			dev_dbg(&dev->pdev->dev, "call amthi write\n");
-			rets = amthi_write(dev, write_cb);
-
-			if (rets) {
-				dev_dbg(&dev->pdev->dev, "amthi write failed with status = %d\n",
-				    rets);
-				goto unlock_dev;
-			}
-			rets = length;
+		if (rets) {
+			dev_err(&dev->pdev->dev,
+				"amthi write failed with status = %d\n", rets);
+			goto err;
 		}
 		mutex_unlock(&dev->device_lock);
-		return rets;
+		return length;
 	}
 
-	write_cb->major_file_operations = MEI_WRITE;
-	/* make sure information is zero before we start */
-
-	write_cb->information = 0;
-	write_cb->request_buffer.size = length;
+	write_cb->fop_type = MEI_FOP_WRITE;
 
 	dev_dbg(&dev->pdev->dev, "host client = %d, ME client = %d\n",
 	    cl->host_client_id, cl->me_client_id);
-	if (cl->state != MEI_FILE_CONNECTED) {
-		rets = -ENODEV;
-		dev_dbg(&dev->pdev->dev, "host client = %d,  is not connected to ME client = %d",
-		    cl->host_client_id,
-		    cl->me_client_id);
-		goto unlock_dev;
-	}
-	i = mei_me_cl_by_id(dev, cl->me_client_id);
-	if (i < 0) {
-		rets = -ENODEV;
-		goto unlock_dev;
-	}
-	if (length > dev->me_clients[i].props.max_msg_length || length <= 0) {
-		rets = -EINVAL;
-		goto unlock_dev;
-	}
-	write_cb->file_private = cl;
-
 	rets = mei_flow_ctrl_creds(dev, cl);
 	if (rets < 0)
-		goto unlock_dev;
+		goto err;
 
-	if (rets && dev->mei_host_buffer_is_empty) {
-		rets = 0;
-		dev->mei_host_buffer_is_empty = false;
-		if (length >  mei_hbuf_max_data(dev)) {
-			mei_hdr.length = mei_hbuf_max_data(dev);
-			mei_hdr.msg_complete = 0;
-		} else {
-			mei_hdr.length = length;
-			mei_hdr.msg_complete = 1;
-		}
-		mei_hdr.host_addr = cl->host_client_id;
-		mei_hdr.me_addr = cl->me_client_id;
-		mei_hdr.reserved = 0;
-		dev_dbg(&dev->pdev->dev, "call mei_write_message header=%08x.\n",
-		    *((u32 *) &mei_hdr));
-		if (mei_write_message(dev, &mei_hdr,
-			(unsigned char *) (write_cb->request_buffer.data),
-			mei_hdr.length)) {
-			rets = -ENODEV;
-			goto unlock_dev;
-		}
+	if (rets == 0 || dev->mei_host_buffer_is_empty == false) {
+		write_cb->buf_idx = 0;
+		mei_hdr.msg_complete = 0;
 		cl->writing_state = MEI_WRITING;
-		write_cb->information = mei_hdr.length;
-		if (mei_hdr.msg_complete) {
-			if (mei_flow_ctrl_reduce(dev, cl)) {
-				rets = -ENODEV;
-				goto unlock_dev;
-			}
-			list_add_tail(&write_cb->cb_list,
-				      &dev->write_waiting_list.mei_cb.cb_list);
-		} else {
-			list_add_tail(&write_cb->cb_list,
-				      &dev->write_list.mei_cb.cb_list);
-		}
+		goto out;
+	}
 
+	dev->mei_host_buffer_is_empty = false;
+	if (length >  mei_hbuf_max_data(dev)) {
+		mei_hdr.length = mei_hbuf_max_data(dev);
+		mei_hdr.msg_complete = 0;
 	} else {
+		mei_hdr.length = length;
+		mei_hdr.msg_complete = 1;
+	}
+	mei_hdr.host_addr = cl->host_client_id;
+	mei_hdr.me_addr = cl->me_client_id;
+	mei_hdr.reserved = 0;
+	dev_dbg(&dev->pdev->dev, "call mei_write_message header=%08x.\n",
+	    *((u32 *) &mei_hdr));
+	if (mei_write_message(dev, &mei_hdr,
+		write_cb->request_buffer.data, mei_hdr.length)) {
+		rets = -ENODEV;
+		goto err;
+	}
+	cl->writing_state = MEI_WRITING;
+	write_cb->buf_idx = mei_hdr.length;
 
-		write_cb->information = 0;
-		cl->writing_state = MEI_WRITING;
-		list_add_tail(&write_cb->cb_list,
-			      &dev->write_list.mei_cb.cb_list);
+out:
+	if (mei_hdr.msg_complete) {
+		if (mei_flow_ctrl_reduce(dev, cl)) {
+			rets = -ENODEV;
+			goto err;
+		}
+		list_add_tail(&write_cb->list, &dev->write_waiting_list.list);
+	} else {
+		list_add_tail(&write_cb->list, &dev->write_list.list);
 	}
+
 	mutex_unlock(&dev->device_lock);
 	return length;
 
-unlock_dev:
+err:
 	mutex_unlock(&dev->device_lock);
-	mei_free_cb_private(write_cb);
+	mei_io_cb_free(write_cb);
 	return rets;
 }
 
@@ -860,15 +694,7 @@ static unsigned int mei_poll(struct file *file, poll_table *wait)
 
 
 	if (cl == &dev->iamthif_cl) {
-		mutex_unlock(&dev->device_lock);
-		poll_wait(file, &dev->iamthif_cl.wait, wait);
-		mutex_lock(&dev->device_lock);
-		if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE &&
-			dev->iamthif_file_object == file) {
-			mask |= (POLLIN | POLLRDNORM);
-			dev_dbg(&dev->pdev->dev, "run next amthi cb\n");
-			mei_run_next_iamthif_cmd(dev);
-		}
+		mask = mei_amthif_poll(dev, file, wait);
 		goto out;
 	}
 
@@ -917,7 +743,7 @@ static struct miscdevice  mei_misc_device = {
  *
  * returns true if ME Interface is valid, false otherwise
  */
-static bool __devinit mei_quirk_probe(struct pci_dev *pdev,
+static bool mei_quirk_probe(struct pci_dev *pdev,
 				const struct pci_device_id *ent)
 {
 	u32 reg;
@@ -939,7 +765,7 @@ static bool __devinit mei_quirk_probe(struct pci_dev *pdev,
  *
  * returns 0 on success, <0 on failure.
  */
-static int __devinit mei_probe(struct pci_dev *pdev,
+static int mei_probe(struct pci_dev *pdev,
 				const struct pci_device_id *ent)
 {
 	struct mei_device *dev;
@@ -1003,6 +829,8 @@ static int __devinit mei_probe(struct pci_dev *pdev,
 		goto disable_msi;
 	}
 	INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
+	INIT_WORK(&dev->init_work, mei_host_client_init);
+
 	if (mei_hw_init(dev)) {
 		dev_err(&pdev->dev, "init hw failure.\n");
 		err = -ENODEV;
@@ -1054,7 +882,7 @@ end:
  * mei_remove is called by the PCI subsystem to alert the driver
  * that it should release a PCI device.
  */
-static void __devexit mei_remove(struct pci_dev *pdev)
+static void mei_remove(struct pci_dev *pdev)
 {
 	struct mei_device *dev;
 
@@ -1087,8 +915,8 @@ static void __devexit mei_remove(struct pci_dev *pdev)
 
 	/* remove entry if already in list */
 	dev_dbg(&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_me_cl_unlink(dev, &dev->wd_cl);
+	mei_me_cl_unlink(dev, &dev->iamthif_cl);
 
 	dev->iamthif_current_cb = NULL;
 	dev->me_clients_num = 0;
@@ -1195,8 +1023,8 @@ static struct pci_driver mei_driver = {
 	.name = KBUILD_MODNAME,
 	.id_table = mei_pci_tbl,
 	.probe = mei_probe,
-	.remove = __devexit_p(mei_remove),
-	.shutdown = __devexit_p(mei_remove),
+	.remove = mei_remove,
+	.shutdown = mei_remove,
 	.driver.pm = MEI_PM_OPS,
 };
 
diff --git a/drivers/misc/mei/mei_dev.h b/drivers/misc/mei/mei_dev.h
index adb35fb9281c..25da04549d04 100644
--- a/drivers/misc/mei/mei_dev.h
+++ b/drivers/misc/mei/mei_dev.h
@@ -19,6 +19,7 @@
 
 #include <linux/types.h>
 #include <linux/watchdog.h>
+#include <linux/poll.h>
 #include <linux/mei.h>
 #include "hw.h"
 
@@ -125,13 +126,20 @@ enum mei_wd_states {
 	MEI_WD_STOPPING,
 };
 
-/* MEI CB */
-enum mei_cb_major_types {
-	MEI_READ = 0,
-	MEI_WRITE,
-	MEI_IOCTL,
-	MEI_OPEN,
-	MEI_CLOSE
+/**
+ * enum mei_cb_file_ops  - file operation associated with the callback
+ * @MEI_FOP_READ   - read
+ * @MEI_FOP_WRITE  - write
+ * @MEI_FOP_IOCTL  - ioctl
+ * @MEI_FOP_OPEN   - open
+ * @MEI_FOP_CLOSE  - close
+ */
+enum mei_cb_file_ops {
+	MEI_FOP_READ = 0,
+	MEI_FOP_WRITE,
+	MEI_FOP_IOCTL,
+	MEI_FOP_OPEN,
+	MEI_FOP_CLOSE
 };
 
 /*
@@ -143,13 +151,21 @@ struct mei_message_data {
 };
 
 
+struct mei_cl;
+
+/**
+ * struct mei_cl_cb - file operation callback structure
+ *
+ * @cl - file client who is running this operation
+ * @fop_type - file operation type
+ */
 struct mei_cl_cb {
-	struct list_head cb_list;
-	enum mei_cb_major_types major_file_operations;
-	void *file_private;
+	struct list_head list;
+	struct mei_cl *cl;
+	enum mei_cb_file_ops fop_type;
 	struct mei_message_data request_buffer;
 	struct mei_message_data response_buffer;
-	unsigned long information;
+	unsigned long buf_idx;
 	unsigned long read_time;
 	struct file *file_object;
 };
@@ -175,29 +191,23 @@ struct mei_cl {
 	struct mei_cl_cb *read_cb;
 };
 
-struct mei_io_list {
-	struct mei_cl_cb mei_cb;
-};
-
 /**
- * struct mei_deive -  MEI private device struct
+ * struct mei_device -  MEI private device struct
  * @hbuf_depth - depth of host(write) buffer
+ * @wr_ext_msg - buffer for hbm control responses (set in read cycle)
  */
 struct mei_device {
 	struct pci_dev *pdev;	/* pointer to pci device struct */
 	/*
 	 * lists of queues
 	 */
-	 /* array of pointers to aio lists */
-	struct mei_io_list read_list;		/* driver read queue */
-	struct mei_io_list write_list;		/* driver write queue */
-	struct mei_io_list write_waiting_list;	/* write waiting queue */
-	struct mei_io_list ctrl_wr_list;	/* managed write IOCTL list */
-	struct mei_io_list ctrl_rd_list;	/* managed read IOCTL list */
-	struct mei_io_list amthi_cmd_list;	/* amthi list for cmd waiting */
-
-	/* driver managed amthi list for reading completed amthi cmd data */
-	struct mei_io_list amthi_read_complete_list;
+	/* array of pointers to aio lists */
+	struct mei_cl_cb read_list;		/* driver read queue */
+	struct mei_cl_cb write_list;		/* driver write queue */
+	struct mei_cl_cb write_waiting_list;	/* write waiting queue */
+	struct mei_cl_cb ctrl_wr_list;		/* managed write IOCTL list */
+	struct mei_cl_cb ctrl_rd_list;		/* managed read IOCTL list */
+
 	/*
 	 * list of files
 	 */
@@ -235,11 +245,13 @@ struct mei_device {
 	u16 init_clients_timer;
 	bool need_reset;
 
-	u32 extra_write_index;
 	unsigned char rd_msg_buf[MEI_RD_MSG_BUF_SIZE];	/* control messages */
-	u32 wr_msg_buf[128];	/* used for control messages */
-	u32 ext_msg_buf[8];	/* for control responses */
 	u32 rd_msg_hdr;
+	u32 wr_msg_buf[128];	/* used for control messages */
+	struct {
+		struct mei_msg_hdr hdr;
+		unsigned char data[4];	/* All HBM messages are 4 bytes */
+	} wr_ext_msg;		/* for control responses */
 
 	struct hbm_version version;
 
@@ -253,12 +265,15 @@ struct mei_device {
 
 	struct mei_cl wd_cl;
 	enum mei_wd_states wd_state;
-	bool wd_interface_reg;
 	bool wd_pending;
 	u16 wd_timeout;
 	unsigned char wd_data[MEI_WD_START_MSG_SIZE];
 
 
+	/* amthif list for cmd waiting */
+	struct mei_cl_cb amthif_cmd_list;
+	/* driver managed amthif list for reading completed amthif cmd data */
+	struct mei_cl_cb amthif_rd_complete_list;
 	struct file *iamthif_file_object;
 	struct mei_cl iamthif_cl;
 	struct mei_cl_cb *iamthif_current_cb;
@@ -272,8 +287,15 @@ struct mei_device {
 	bool iamthif_flow_control_pending;
 	bool iamthif_ioctl;
 	bool iamthif_canceled;
+
+	struct work_struct init_work;
 };
 
+static inline unsigned long mei_secs_to_jiffies(unsigned long sec)
+{
+	return msecs_to_jiffies(sec * MSEC_PER_SEC);
+}
+
 
 /*
  * mei init function prototypes
@@ -284,21 +306,34 @@ int mei_hw_init(struct mei_device *dev);
 int mei_task_initialize_clients(void *data);
 int mei_initialize_clients(struct mei_device *dev);
 int mei_disconnect_host_client(struct mei_device *dev, struct mei_cl *cl);
-void mei_remove_client_from_file_list(struct mei_device *dev, u8 host_client_id);
-void mei_host_init_iamthif(struct mei_device *dev);
 void mei_allocate_me_clients_storage(struct mei_device *dev);
 
 
-int mei_me_cl_update_filext(struct mei_device *dev, struct mei_cl *cl,
+int mei_me_cl_link(struct mei_device *dev, struct mei_cl *cl,
 			const uuid_le *cguid, u8 host_client_id);
+void mei_me_cl_unlink(struct mei_device *dev, struct mei_cl *cl);
 int mei_me_cl_by_uuid(const struct mei_device *dev, const uuid_le *cuuid);
 int mei_me_cl_by_id(struct mei_device *dev, u8 client_id);
 
 /*
- * MEI IO List Functions
+ * MEI IO Functions
+ */
+struct mei_cl_cb *mei_io_cb_init(struct mei_cl *cl, struct file *fp);
+void mei_io_cb_free(struct mei_cl_cb *priv_cb);
+int mei_io_cb_alloc_req_buf(struct mei_cl_cb *cb, size_t length);
+int mei_io_cb_alloc_resp_buf(struct mei_cl_cb *cb, size_t length);
+
+
+/**
+ * mei_io_list_init - Sets up a queue list.
+ *
+ * @list: An instance cl callback structure
  */
-void mei_io_list_init(struct mei_io_list *list);
-void mei_io_list_flush(struct mei_io_list *list, struct mei_cl *cl);
+static inline void mei_io_list_init(struct mei_cl_cb *list)
+{
+	INIT_LIST_HEAD(&list->list);
+}
+void mei_io_list_flush(struct mei_cl_cb *list, struct mei_cl *cl);
 
 /*
  * MEI ME Client Functions
@@ -330,7 +365,8 @@ static inline bool mei_cl_cmp_id(const struct mei_cl *cl1,
  */
 void mei_host_start_message(struct mei_device *dev);
 void mei_host_enum_clients_message(struct mei_device *dev);
-int mei_host_client_properties(struct mei_device *dev);
+int mei_host_client_enumerate(struct mei_device *dev);
+void mei_host_client_init(struct work_struct *work);
 
 /*
  *  MEI interrupt functions prototype
@@ -347,18 +383,40 @@ int mei_ioctl_connect_client(struct file *file,
 
 int mei_start_read(struct mei_device *dev, struct mei_cl *cl);
 
-int amthi_write(struct mei_device *dev, struct mei_cl_cb *priv_cb);
 
-int amthi_read(struct mei_device *dev, struct file *file,
-	      char __user *ubuf, size_t length, loff_t *offset);
+/*
+ * AMTHIF - AMT Host Interface Functions
+ */
+void mei_amthif_reset_params(struct mei_device *dev);
+
+void mei_amthif_host_init(struct mei_device *dev);
+
+int mei_amthif_write(struct mei_device *dev, struct mei_cl_cb *priv_cb);
 
-struct mei_cl_cb *find_amthi_read_list_entry(struct mei_device *dev,
+int mei_amthif_read(struct mei_device *dev, struct file *file,
+		char __user *ubuf, size_t length, loff_t *offset);
+
+unsigned int mei_amthif_poll(struct mei_device *dev,
+		struct file *file, poll_table *wait);
+
+int mei_amthif_release(struct mei_device *dev, struct file *file);
+
+struct mei_cl_cb *mei_amthif_find_read_list_entry(struct mei_device *dev,
 						struct file *file);
 
-void mei_run_next_iamthif_cmd(struct mei_device *dev);
+void mei_amthif_run_next_cmd(struct mei_device *dev);
+
 
-void mei_free_cb_private(struct mei_cl_cb *priv_cb);
+int mei_amthif_read_message(struct mei_cl_cb *complete_list,
+		struct mei_device *dev, struct mei_msg_hdr *mei_hdr);
 
+int mei_amthif_irq_write_complete(struct mei_device *dev, s32 *slots,
+			struct mei_cl_cb *cb, struct mei_cl_cb *cmpl_list);
+
+void mei_amthif_complete(struct mei_device *dev, struct mei_cl_cb *cb);
+int mei_amthif_irq_read_message(struct mei_cl_cb *complete_list,
+		struct mei_device *dev, struct mei_msg_hdr *mei_hdr);
+int mei_amthif_irq_read(struct mei_device *dev, s32 *slots);
 
 /*
  * Register Access Function
@@ -437,4 +495,15 @@ void mei_csr_clear_his(struct mei_device *dev);
 void mei_enable_interrupts(struct mei_device *dev);
 void mei_disable_interrupts(struct mei_device *dev);
 
+static inline struct mei_msg_hdr *mei_hbm_hdr(u32 *buf, size_t length)
+{
+	struct mei_msg_hdr *hdr = (struct mei_msg_hdr *)buf;
+	hdr->host_addr = 0;
+	hdr->me_addr = 0;
+	hdr->length = length;
+	hdr->msg_complete = 1;
+	hdr->reserved = 0;
+	return hdr;
+}
+
 #endif
diff --git a/drivers/misc/mei/wd.c b/drivers/misc/mei/wd.c
index d96c537f046f..636409f9667f 100644
--- a/drivers/misc/mei/wd.c
+++ b/drivers/misc/mei/wd.c
@@ -62,6 +62,7 @@ static void mei_wd_set_start_timeout(struct mei_device *dev, u16 timeout)
  */
 int mei_wd_host_init(struct mei_device *dev)
 {
+	int id;
 	mei_cl_init(&dev->wd_cl, dev);
 
 	/* look for WD client and connect to it */
@@ -69,12 +70,11 @@ int mei_wd_host_init(struct mei_device *dev)
 	dev->wd_timeout = MEI_WD_DEFAULT_TIMEOUT;
 	dev->wd_state = MEI_WD_IDLE;
 
-	/* find ME WD client */
-	mei_me_cl_update_filext(dev, &dev->wd_cl,
+	/* Connect WD ME client to the host client */
+	id = mei_me_cl_link(dev, &dev->wd_cl,
 				&mei_wd_guid, MEI_WD_HOST_CLIENT_ID);
 
-	dev_dbg(&dev->pdev->dev, "wd: check client\n");
-	if (MEI_FILE_CONNECTING != dev->wd_cl.state) {
+	if (id < 0) {
 		dev_info(&dev->pdev->dev, "wd: failed to find the client\n");
 		return -ENOENT;
 	}
@@ -85,7 +85,7 @@ int mei_wd_host_init(struct mei_device *dev)
 		dev->wd_cl.host_client_id = 0;
 		return -EIO;
 	}
-	dev->wd_cl.timer_count = CONNECT_TIMEOUT;
+	dev->wd_cl.timer_count = MEI_CONNECT_TIMEOUT;
 
 	return 0;
 }
@@ -360,23 +360,20 @@ void mei_watchdog_register(struct mei_device *dev)
 	if (watchdog_register_device(&amt_wd_dev)) {
 		dev_err(&dev->pdev->dev,
 			"wd: unable to register watchdog device.\n");
-		dev->wd_interface_reg = false;
 		return;
 	}
 
 	dev_dbg(&dev->pdev->dev,
 		"wd: successfully register watchdog interface.\n");
-	dev->wd_interface_reg = true;
 	watchdog_set_drvdata(&amt_wd_dev, dev);
 }
 
 void mei_watchdog_unregister(struct mei_device *dev)
 {
-	if (!dev->wd_interface_reg)
+	if (test_bit(WDOG_UNREGISTERED, &amt_wd_dev.status))
 		return;
 
 	watchdog_set_drvdata(&amt_wd_dev, NULL);
 	watchdog_unregister_device(&amt_wd_dev);
-	dev->wd_interface_reg = false;
 }