main.c

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/*
 *
 * 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.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/kernel.h>
#include <linux/device.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/poll.h>
#include <linux/init.h>
#include <linux/ioctl.h>
#include <linux/cdev.h>
#include <linux/sched.h>
#include <linux/uuid.h>
#include <linux/compat.h>
#include <linux/jiffies.h>
#include <linux/interrupt.h>
#include <linux/miscdevice.h>

#include "mei_dev.h"
#include <linux/mei.h>
#include "interface.h"

/* AMT device is a singleton on the platform */
static struct pci_dev *mei_pdev;

/* mei_pci_tbl - PCI Device ID Table */
static DEFINE_PCI_DEVICE_TABLE(mei_pci_tbl) = {
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_82946GZ)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_82G35)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_82Q965)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_82G965)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_82GM965)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_82GME965)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_ICH9_82Q35)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_ICH9_82G33)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_ICH9_82Q33)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_ICH9_82X38)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_ICH9_3200)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_ICH9_6)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_ICH9_7)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_ICH9_8)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_ICH9_9)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_ICH9_10)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_ICH9M_1)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_ICH9M_2)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_ICH9M_3)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_ICH9M_4)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_ICH10_1)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_ICH10_2)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_ICH10_3)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_ICH10_4)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_IBXPK_1)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_IBXPK_2)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_CPT_1)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_PBG_1)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_PPT_1)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_PPT_2)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_PPT_3)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_LPT)},
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, MEI_DEV_ID_LPT_LP)},

    /* required last entry */
    {0, }
};

MODULE_DEVICE_TABLE(pci, mei_pci_tbl);

static DEFINE_MUTEX(mei_mutex);


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;
}

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;
}
static struct mei_cl_cb *find_read_list_entry(
        struct mei_device *dev,
        struct mei_cl *cl)
{
    struct mei_cl_cb *pos = NULL;
    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))
            return pos;
    }
    return NULL;
}

static int mei_open(struct inode *inode, struct file *file)
{
    struct mei_cl *cl;
    struct mei_device *dev;
    unsigned long cl_id;
    int err;

    err = -ENODEV;
    if (!mei_pdev)
        goto out;

    dev = pci_get_drvdata(mei_pdev);
    if (!dev)
        goto out;

    mutex_lock(&dev->device_lock);
    err = -ENOMEM;
    cl = mei_cl_allocate(dev);
    if (!cl)
        goto out_unlock;

    err = -ENODEV;
    if (dev->dev_state != MEI_DEV_ENABLED) {
        dev_dbg(&dev->pdev->dev, "dev_state != MEI_ENABLED  dev_state = %s\n",
            mei_dev_state_str(dev->dev_state));
        goto out_unlock;
    }
    err = -EMFILE;
    if (dev->open_handle_count >= MEI_MAX_OPEN_HANDLE_COUNT) {
        dev_err(&dev->pdev->dev, "open_handle_count exceded %d",
            MEI_MAX_OPEN_HANDLE_COUNT);
        goto out_unlock;
    }

    cl_id = find_first_zero_bit(dev->host_clients_map, MEI_CLIENTS_MAX);
    if (cl_id >= MEI_CLIENTS_MAX) {
        dev_err(&dev->pdev->dev, "client_id exceded %d",
                MEI_CLIENTS_MAX) ;
        goto out_unlock;
    }

    cl->host_client_id  = cl_id;

    dev_dbg(&dev->pdev->dev, "client_id = %d\n", cl->host_client_id);

    dev->open_handle_count++;

    list_add_tail(&cl->link, &dev->file_list);

    set_bit(cl->host_client_id, dev->host_clients_map);
    cl->state = MEI_FILE_INITIALIZING;
    cl->sm_state = 0;

    file->private_data = cl;
    mutex_unlock(&dev->device_lock);

    return nonseekable_open(inode, file);

out_unlock:
    mutex_unlock(&dev->device_lock);
    kfree(cl);
out:
    return err;
}

static int mei_release(struct inode *inode, struct file *file)
{
    struct mei_cl *cl = file->private_data;
    struct mei_cl_cb *cb;
    struct mei_device *dev;
    int rets = 0;

    if (WARN_ON(!cl || !cl->dev))
        return -ENODEV;

    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",
            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_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;
        }

        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);
            }
        }

        if (mei_clear_lists(dev, file))
            dev->iamthif_state = MEI_IAMTHIF_IDLE;

    }
    mutex_unlock(&dev->device_lock);
    return rets;
}


static ssize_t mei_read(struct file *file, char __user *ubuf,
            size_t length, loff_t *offset)
{
    struct mei_cl *cl = file->private_data;
    struct mei_cl_cb *cb_pos = NULL;
    struct mei_cl_cb *cb = NULL;
    struct mei_device *dev;
    int i;
    int rets;
    int err;


    if (WARN_ON(!cl || !cl->dev))
        return -ENODEV;

    dev = cl->dev;

    mutex_lock(&dev->device_lock);
    if (dev->dev_state != MEI_DEV_ENABLED) {
        rets = -ENODEV;
        goto out;
    }

    if ((cl->sm_state & MEI_WD_STATE_INDEPENDENCE_MSG_SENT) == 0) {
        /* Do not allow to read watchdog client */
        i = mei_me_cl_by_uuid(dev, &mei_wd_guid);
        if (i >= 0) {
            struct mei_me_client *me_client = &dev->me_clients[i];
            if (cl->me_client_id == me_client->client_id) {
                rets = -EBADF;
                goto out;
            }
        }
    } else {
        cl->sm_state &= ~MEI_WD_STATE_INDEPENDENCE_MSG_SENT;
    }

    if (cl == &dev->iamthif_cl) {
        rets = amthi_read(dev, file, ubuf, length, offset);
        goto out;
    }

    if (cl->read_cb && cl->read_cb->information > *offset) {
        cb = cl->read_cb;
        goto copy_buffer;
    } else if (cl->read_cb && cl->read_cb->information > 0 &&
           cl->read_cb->information <= *offset) {
        cb = cl->read_cb;
        rets = 0;
        goto free;
    } else if ((!cl->read_cb || !cl->read_cb->information) &&
            *offset > 0) {
        /*Offset needs to be cleaned for contiguous reads*/
        *offset = 0;
        rets = 0;
        goto out;
    }

    err = mei_start_read(dev, cl);
    if (err && err != -EBUSY) {
        dev_dbg(&dev->pdev->dev,
            "mei start read failure with status = %d\n", err);
        rets = err;
        goto out;
    }

    if (MEI_READ_COMPLETE != cl->reading_state &&
            !waitqueue_active(&cl->rx_wait)) {
        if (file->f_flags & O_NONBLOCK) {
            rets = -EAGAIN;
            goto out;
        }

        mutex_unlock(&dev->device_lock);

        if (wait_event_interruptible(cl->rx_wait,
            (MEI_READ_COMPLETE == cl->reading_state ||
             MEI_FILE_INITIALIZING == cl->state ||
             MEI_FILE_DISCONNECTED == cl->state ||
             MEI_FILE_DISCONNECTING == cl->state))) {
            if (signal_pending(current))
                return -EINTR;
            return -ERESTARTSYS;
        }

        mutex_lock(&dev->device_lock);
        if (MEI_FILE_INITIALIZING == cl->state ||
            MEI_FILE_DISCONNECTED == cl->state ||
            MEI_FILE_DISCONNECTING == cl->state) {
            rets = -EBUSY;
            goto out;
        }
    }

    cb = cl->read_cb;

    if (!cb) {
        rets = -ENODEV;
        goto out;
    }
    if (cl->reading_state != MEI_READ_COMPLETE) {
        rets = 0;
        goto out;
    }
    /* now copy the data to user space */
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) {
        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));

    if (copy_to_user(ubuf, cb->response_buffer.data + *offset, length)) {
        rets = -EFAULT;
        goto free;
    }

    rets = length;
    *offset += length;
    if ((unsigned long)*offset < cb->information)
        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);
    cl->reading_state = MEI_IDLE;
    cl->read_cb = NULL;
    cl->read_pending = 0;
out:
    dev_dbg(&dev->pdev->dev, "end mei read rets= %d\n", rets);
    mutex_unlock(&dev->device_lock);
    return rets;
}

static ssize_t mei_write(struct file *file, const char __user *ubuf,
             size_t length, loff_t *offset)
{
    struct mei_cl *cl = file->private_data;
    struct mei_cl_cb *write_cb = NULL;
    struct mei_msg_hdr mei_hdr;
    struct mei_device *dev;
    unsigned long timeout = 0;
    int rets;
    int i;

    if (WARN_ON(!cl || !cl->dev))
        return -ENODEV;

    dev = cl->dev;

    mutex_lock(&dev->device_lock);

    if (dev->dev_state != MEI_DEV_ENABLED) {
        mutex_unlock(&dev->device_lock);
        return -ENODEV;
    }

    if (cl == &dev->iamthif_cl) {
        write_cb = find_amthi_read_list_entry(dev, file);

        if (write_cb) {
            timeout = write_cb->read_time +
                    msecs_to_jiffies(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;
            }
        }
    }

    /* free entry used in read */
    if (cl->reading_state == MEI_READ_COMPLETE) {
        *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);
            write_cb = NULL;
            cl->reading_state = MEI_IDLE;
            cl->read_cb = NULL;
            cl->read_pending = 0;
        }
    } else if (cl->reading_state == MEI_IDLE && !cl->read_pending)
        *offset = 0;


    write_cb = kzalloc(sizeof(struct mei_cl_cb), GFP_KERNEL);
    if (!write_cb) {
        mutex_unlock(&dev->device_lock);
        return -ENOMEM;
    }

    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);

    rets = -EFAULT;
    if (copy_from_user(write_cb->request_buffer.data, ubuf, length))
        goto unlock_dev;

    cl->sm_state = 0;
    if (length == 4 &&
        ((memcmp(mei_wd_state_independence_msg[0],
                 write_cb->request_buffer.data, 4) == 0) ||
         (memcmp(mei_wd_state_independence_msg[1],
                 write_cb->request_buffer.data, 4) == 0) ||
         (memcmp(mei_wd_state_independence_msg[2],
                 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;
        }

        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;
        }
        mutex_unlock(&dev->device_lock);
        return rets;
    }

    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;

    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;

    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;
        }
        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);
        }

    } else {

        write_cb->information = 0;
        cl->writing_state = MEI_WRITING;
        list_add_tail(&write_cb->cb_list,
                  &dev->write_list.mei_cb.cb_list);
    }
    mutex_unlock(&dev->device_lock);
    return length;

unlock_dev:
    mutex_unlock(&dev->device_lock);
    mei_free_cb_private(write_cb);
    return rets;
}


static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
{
    struct mei_device *dev;
    struct mei_cl *cl = file->private_data;
    struct mei_connect_client_data *connect_data = NULL;
    int rets;

    if (cmd != IOCTL_MEI_CONNECT_CLIENT)
        return -EINVAL;

    if (WARN_ON(!cl || !cl->dev))
        return -ENODEV;

    dev = cl->dev;

    dev_dbg(&dev->pdev->dev, "IOCTL cmd = 0x%x", cmd);

    mutex_lock(&dev->device_lock);
    if (dev->dev_state != MEI_DEV_ENABLED) {
        rets = -ENODEV;
        goto out;
    }

    dev_dbg(&dev->pdev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");

    connect_data = kzalloc(sizeof(struct mei_connect_client_data),
                            GFP_KERNEL);
    if (!connect_data) {
        rets = -ENOMEM;
        goto out;
    }
    dev_dbg(&dev->pdev->dev, "copy connect data from user\n");
    if (copy_from_user(connect_data, (char __user *)data,
                sizeof(struct mei_connect_client_data))) {
        dev_dbg(&dev->pdev->dev, "failed to copy data from userland\n");
        rets = -EFAULT;
        goto out;
    }
    rets = mei_ioctl_connect_client(file, connect_data);

    /* if all is ok, copying the data back to user. */
    if (rets)
        goto out;

    dev_dbg(&dev->pdev->dev, "copy connect data to user\n");
    if (copy_to_user((char __user *)data, connect_data,
                sizeof(struct mei_connect_client_data))) {
        dev_dbg(&dev->pdev->dev, "failed to copy data to userland\n");
        rets = -EFAULT;
        goto out;
    }

out:
    kfree(connect_data);
    mutex_unlock(&dev->device_lock);
    return rets;
}

#ifdef CONFIG_COMPAT
static long mei_compat_ioctl(struct file *file,
            unsigned int cmd, unsigned long data)
{
    return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data));
}
#endif


static unsigned int mei_poll(struct file *file, poll_table *wait)
{
    struct mei_cl *cl = file->private_data;
    struct mei_device *dev;
    unsigned int mask = 0;

    if (WARN_ON(!cl || !cl->dev))
        return mask;

    dev = cl->dev;

    mutex_lock(&dev->device_lock);

    if (dev->dev_state != MEI_DEV_ENABLED)
        goto out;


    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);
        }
        goto out;
    }

    mutex_unlock(&dev->device_lock);
    poll_wait(file, &cl->tx_wait, wait);
    mutex_lock(&dev->device_lock);
    if (MEI_WRITE_COMPLETE == cl->writing_state)
        mask |= (POLLIN | POLLRDNORM);

out:
    mutex_unlock(&dev->device_lock);
    return mask;
}

/*
 * file operations structure will be used for mei char device.
 */
static const struct file_operations mei_fops = {
    .owner = THIS_MODULE,
    .read = mei_read,
    .unlocked_ioctl = mei_ioctl,
#ifdef CONFIG_COMPAT
    .compat_ioctl = mei_compat_ioctl,
#endif
    .open = mei_open,
    .release = mei_release,
    .write = mei_write,
    .poll = mei_poll,
    .llseek = no_llseek
};


/*
 * Misc Device Struct
 */
static struct miscdevice  mei_misc_device = {
        .name = "mei",
        .fops = &mei_fops,
        .minor = MISC_DYNAMIC_MINOR,
};

static bool __devinit mei_quirk_probe(struct pci_dev *pdev,
                const struct pci_device_id *ent)
{
    u32 reg;
    if (ent->device == MEI_DEV_ID_PBG_1) {
        pci_read_config_dword(pdev, 0x48, &reg);
        /* make sure that bit 9 is up and bit 10 is down */
        if ((reg & 0x600) == 0x200) {
            dev_info(&pdev->dev, "Device doesn't have valid ME Interface\n");
            return false;
        }
    }
    return true;
}
static int __devinit mei_probe(struct pci_dev *pdev,
                const struct pci_device_id *ent)
{
    struct mei_device *dev;
    int err;

    mutex_lock(&mei_mutex);

    if (!mei_quirk_probe(pdev, ent)) {
        err = -ENODEV;
        goto end;
    }

    if (mei_pdev) {
        err = -EEXIST;
        goto end;
    }
    /* enable pci dev */
    err = pci_enable_device(pdev);
    if (err) {
        dev_err(&pdev->dev, "failed to enable pci device.\n");
        goto end;
    }
    /* set PCI host mastering  */
    pci_set_master(pdev);
    /* pci request regions for mei driver */
    err = pci_request_regions(pdev, KBUILD_MODNAME);
    if (err) {
        dev_err(&pdev->dev, "failed to get pci regions.\n");
        goto disable_device;
    }
    /* allocates and initializes the mei dev structure */
    dev = mei_device_init(pdev);
    if (!dev) {
        err = -ENOMEM;
        goto release_regions;
    }
    /* mapping  IO device memory */
    dev->mem_addr = pci_iomap(pdev, 0, 0);
    if (!dev->mem_addr) {
        dev_err(&pdev->dev, "mapping I/O device memory failure.\n");
        err = -ENOMEM;
        goto free_device;
    }
    pci_enable_msi(pdev);

     /* request and enable interrupt */
    if (pci_dev_msi_enabled(pdev))
        err = request_threaded_irq(pdev->irq,
            NULL,
            mei_interrupt_thread_handler,
            IRQF_ONESHOT, KBUILD_MODNAME, dev);
    else
        err = request_threaded_irq(pdev->irq,
            mei_interrupt_quick_handler,
            mei_interrupt_thread_handler,
            IRQF_SHARED, KBUILD_MODNAME, dev);

    if (err) {
        dev_err(&pdev->dev, "request_threaded_irq failure. irq = %d\n",
               pdev->irq);
        goto disable_msi;
    }
    INIT_DELAYED_WORK(&dev->timer_work, mei_timer);
    if (mei_hw_init(dev)) {
        dev_err(&pdev->dev, "init hw failure.\n");
        err = -ENODEV;
        goto release_irq;
    }

    err = misc_register(&mei_misc_device);
    if (err)
        goto release_irq;

    mei_pdev = pdev;
    pci_set_drvdata(pdev, dev);


    schedule_delayed_work(&dev->timer_work, HZ);

    mutex_unlock(&mei_mutex);

    pr_debug("initialization successful.\n");

    return 0;

release_irq:
    /* disable interrupts */
    dev->host_hw_state = mei_hcsr_read(dev);
    mei_disable_interrupts(dev);
    flush_scheduled_work();
    free_irq(pdev->irq, dev);
disable_msi:
    pci_disable_msi(pdev);
    pci_iounmap(pdev, dev->mem_addr);
free_device:
    kfree(dev);
release_regions:
    pci_release_regions(pdev);
disable_device:
    pci_disable_device(pdev);
end:
    mutex_unlock(&mei_mutex);
    dev_err(&pdev->dev, "initialization failed.\n");
    return err;
}

static void __devexit mei_remove(struct pci_dev *pdev)
{
    struct mei_device *dev;

    if (mei_pdev != pdev)
        return;

    dev = pci_get_drvdata(pdev);
    if (!dev)
        return;

    mutex_lock(&dev->device_lock);

    cancel_delayed_work(&dev->timer_work);

    mei_wd_stop(dev);

    mei_pdev = NULL;

    if (dev->iamthif_cl.state == MEI_FILE_CONNECTED) {
        dev->iamthif_cl.state = MEI_FILE_DISCONNECTING;
        mei_disconnect_host_client(dev, &dev->iamthif_cl);
    }
    if (dev->wd_cl.state == MEI_FILE_CONNECTED) {
        dev->wd_cl.state = MEI_FILE_DISCONNECTING;
        mei_disconnect_host_client(dev, &dev->wd_cl);
    }

    /* Unregistering watchdog device */
    mei_watchdog_unregister(dev);

    /* 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);

    dev->iamthif_current_cb = NULL;
    dev->me_clients_num = 0;

    mutex_unlock(&dev->device_lock);

    flush_scheduled_work();

    /* disable interrupts */
    mei_disable_interrupts(dev);

    free_irq(pdev->irq, dev);
    pci_disable_msi(pdev);
    pci_set_drvdata(pdev, NULL);

    if (dev->mem_addr)
        pci_iounmap(pdev, dev->mem_addr);

    kfree(dev);

    pci_release_regions(pdev);
    pci_disable_device(pdev);

    misc_deregister(&mei_misc_device);
}
#ifdef CONFIG_PM
static int mei_pci_suspend(struct device *device)
{
    struct pci_dev *pdev = to_pci_dev(device);
    struct mei_device *dev = pci_get_drvdata(pdev);
    int err;

    if (!dev)
        return -ENODEV;
    mutex_lock(&dev->device_lock);

    cancel_delayed_work(&dev->timer_work);

    /* Stop watchdog if exists */
    err = mei_wd_stop(dev);
    /* Set new mei state */
    if (dev->dev_state == MEI_DEV_ENABLED ||
        dev->dev_state == MEI_DEV_RECOVERING_FROM_RESET) {
        dev->dev_state = MEI_DEV_POWER_DOWN;
        mei_reset(dev, 0);
    }
    mutex_unlock(&dev->device_lock);

    free_irq(pdev->irq, dev);
    pci_disable_msi(pdev);

    return err;
}

static int mei_pci_resume(struct device *device)
{
    struct pci_dev *pdev = to_pci_dev(device);
    struct mei_device *dev;
    int err;

    dev = pci_get_drvdata(pdev);
    if (!dev)
        return -ENODEV;

    pci_enable_msi(pdev);

    /* request and enable interrupt */
    if (pci_dev_msi_enabled(pdev))
        err = request_threaded_irq(pdev->irq,
            NULL,
            mei_interrupt_thread_handler,
            IRQF_ONESHOT, KBUILD_MODNAME, dev);
    else
        err = request_threaded_irq(pdev->irq,
            mei_interrupt_quick_handler,
            mei_interrupt_thread_handler,
            IRQF_SHARED, KBUILD_MODNAME, dev);

    if (err) {
        dev_err(&pdev->dev, "request_threaded_irq failed: irq = %d.\n",
                pdev->irq);
        return err;
    }

    mutex_lock(&dev->device_lock);
    dev->dev_state = MEI_DEV_POWER_UP;
    mei_reset(dev, 1);
    mutex_unlock(&dev->device_lock);

    /* Start timer if stopped in suspend */
    schedule_delayed_work(&dev->timer_work, HZ);

    return err;
}
static SIMPLE_DEV_PM_OPS(mei_pm_ops, mei_pci_suspend, mei_pci_resume);
#define MEI_PM_OPS  (&mei_pm_ops)
#else
#define MEI_PM_OPS  NULL
#endif /* CONFIG_PM */
/*
 *  PCI driver structure
 */
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),
    .driver.pm = MEI_PM_OPS,
};

module_pci_driver(mei_driver);

MODULE_AUTHOR("Intel Corporation");
MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
MODULE_LICENSE("GPL v2");