mei: extract AMTHI functions into the amthif.c file (19838fb8) · Commits · e / devices / android_kernel_oneplus_sm7250

drivers/misc/mei/Makefile

+1 −0

Original line number	Diff line number	Diff line
		@@ -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

drivers/misc/mei/amthif.c

0 → 100644

+572 −0

Original line number	Diff line number	Diff line
		/*
		*
		* 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_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 = 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 *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.list, 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;
		}


		/**
		* 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_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)
		{
		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_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 *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.list, list) {
		list_del(&pos->list);
		cl_tmp = (struct mei_cl *)pos->file_private;

		if (cl_tmp && cl_tmp == &dev->iamthif_cl) {
		status = mei_amthif_write(dev, pos);
		if (status) {
		dev_dbg(&dev->pdev->dev,
		"amthi write failed status = %d\n",
		status);
		return;
		}
		break;
		}
		}
		}

		/**
		* 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_process_completed(struct mei_device dev, s32 slots,
		struct mei_cl_cb *cb_pos,
		struct mei_cl *cl,
		struct mei_cl_cb *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->list);
		return -ENODEV;
		} else {
		if (mei_flow_ctrl_reduce(dev, cl))
		return -ENODEV;
		dev->iamthif_msg_buf_index += mei_hdr->length;
		cb_pos->buf_idx = 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->list,
		&dev->write_waiting_list.list);

		}
		} 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 -= mei_data2slots(mei_hdr->length);

		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->list);
		} else {
		dev->iamthif_msg_buf_index += mei_hdr->length;
		}
		return -EMSGSIZE;
		} else {
		return -EBADMSG;
		}

		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 *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->buf_idx = 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->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->amthi_read_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);
		}

drivers/misc/mei/init.c

+1 −72

Original line number	Diff line number	Diff line
		@@ -43,10 +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_flush - removes list entry belonging to cl.
		*
		@@ -91,23 +87,6 @@ int mei_cl_flush_queues(struct mei_cl *cl)



		/**
		* 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
		*
		@@ -313,7 +292,7 @@ void mei_reset(struct mei_device *dev, int interrupts_enabled)
		mei_remove_client_from_file_list(dev,
		dev->iamthif_cl.host_client_id);

		mei_reset_iamthif_params(dev);
		mei_amthif_reset_params(dev);
		dev->extra_write_index = 0;
		}

		@@ -576,56 +555,6 @@ int mei_me_cl_update_filext(struct mei_device dev, struct mei_cl cl,
		return -ENOENT;
		}

		/**
		* host_init_iamthif - mei initialization iamthif client.
		*
		* @dev: the device structure
		*
		*/
		void mei_host_init_iamthif(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_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 = MEI_CONNECT_TIMEOUT;
		}
		}

		/**
		* mei_alloc_file_private - allocates a private file structure and sets it up.
		* @file: the file structure

drivers/misc/mei/interrupt.c

+10 −208

File changed.

Preview size limit exceeded, changes collapsed.

drivers/misc/mei/iorw.c

+0 −266

Original line number	Diff line number	Diff line
		@@ -319,152 +319,6 @@ int mei_ioctl_connect_client(struct file *file,
		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.list, 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 +
		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_start_read - the start read client message function.
		*
		@@ -524,123 +378,3 @@ int mei_start_read(struct mei_device dev, struct mei_cl cl)
		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->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;
		}

		/**
		* 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.list, list) {
		list_del(&pos->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;
		}
		}
		}