text: /*
   *
   * 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/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 <linux/mei.h>
  
  #include "mei_dev.h"
  #include "client.h"
  
  /**
   * mei_open - the open function
   *
   * @inode: pointer to inode structure
   * @file: pointer to file structure
   *
   * returns 0 on success, <0 on error
   */
  static int mei_open(struct inode *inode, struct file *file)
  {
  	struct miscdevice *misc = file->private_data;
  	struct pci_dev *pdev;
  	struct mei_cl *cl;
  	struct mei_device *dev;
  
  	int err;
  
  	if (!misc->parent)
  		return -ENODEV;
  
  	pdev = container_of(misc->parent, struct pci_dev, dev);
  
  	dev = pci_get_drvdata(pdev);
  	if (!dev)
  		return -ENODEV;
  
  	mutex_lock(&dev->device_lock);
  
  	cl = NULL;
  
  	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 err_unlock;
  	}
  
  	err = -ENOMEM;
  	cl = mei_cl_allocate(dev);
  	if (!cl)
  		goto err_unlock;
  
  	/* open_handle_count check is handled in the mei_cl_link */
  	err = mei_cl_link(cl, MEI_HOST_CLIENT_ID_ANY);
  	if (err)
  		goto err_unlock;
  
  	file->private_data = cl;
  
  	mutex_unlock(&dev->device_lock);
  
  	return nonseekable_open(inode, file);
  
  err_unlock:
  	mutex_unlock(&dev->device_lock);
  	kfree(cl);
  	return err;
  }
  
  /**
   * mei_release - the release function
   *
   * @inode: pointer to inode structure
   * @file: pointer to file structure
   *
   * returns 0 on success, <0 on error
   */
  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) {
  		rets = mei_amthif_release(dev, file);
  		goto out;
  	}
  	if (cl->state == MEI_FILE_CONNECTED) {
  		cl->state = MEI_FILE_DISCONNECTING;
  		cl_dbg(dev, cl, "disconnecting\n");
  		rets = mei_cl_disconnect(cl);
  	}
  	mei_cl_flush_queues(cl);
  	cl_dbg(dev, cl, "removing\n");
  
  	mei_cl_unlink(cl);
  
  
  	/* free read cb */
  	cb = NULL;
  	if (cl->read_cb) {
  		cb = mei_cl_find_read_cb(cl);
  		/* Remove entry from read list */
  		if (cb)
  			list_del(&cb->list);
  
  		cb = cl->read_cb;
  		cl->read_cb = NULL;
  	}
  
  	file->private_data = NULL;
  
  	mei_io_cb_free(cb);
  
  	kfree(cl);
  out:
  	mutex_unlock(&dev->device_lock);
  	return rets;
  }
  
  
  /**
   * mei_read - the read function.
   *
   * @file: pointer to file structure
   * @ubuf: pointer to user buffer
   * @length: buffer length
   * @offset: data offset in buffer
   *
   * returns >=0 data length on success , <0 on error
   */
  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 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 (length == 0) {
  		rets = 0;
  		goto out;
  	}
  
  	if (cl == &dev->iamthif_cl) {
  		rets = mei_amthif_read(dev, file, ubuf, length, offset);
  		goto out;
  	}
  
  	if (cl->read_cb) {
  		cb = cl->read_cb;
  		/* read what left */
  		if (cb->buf_idx > *offset)
  			goto copy_buffer;
  		/* offset is beyond buf_idx we have no more data return 0 */
  		if (cb->buf_idx > 0 && cb->buf_idx <= *offset) {
  			rets = 0;
  			goto free;
  		}
  		/* Offset needs to be cleaned for contiguous reads*/
  		if (cb->buf_idx == 0 && *offset > 0)
  			*offset = 0;
  	} else if (*offset > 0) {
  		*offset = 0;
  	}
  
  	err = mei_cl_read_start(cl, length);
  	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_cl_is_transitioning(cl))) {
  
  			if (signal_pending(current))
  				return -EINTR;
  			return -ERESTARTSYS;
  		}
  
  		mutex_lock(&dev->device_lock);
  		if (mei_cl_is_transitioning(cl)) {
  			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, "buf.size = %d buf.idx= %ld\n",
  	    cb->response_buffer.size, cb->buf_idx);
  	if (length == 0 || ubuf == NULL || *offset > cb->buf_idx) {
  		rets = -EMSGSIZE;
  		goto free;
  	}
  
  	/* 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)) {
  		dev_dbg(&dev->pdev->dev, "failed to copy data to userland\n");
  		rets = -EFAULT;
  		goto free;
  	}
  
  	rets = length;
  	*offset += length;
  	if ((unsigned long)*offset < cb->buf_idx)
  		goto out;
  
  free:
  	cb_pos = mei_cl_find_read_cb(cl);
  	/* Remove entry from read list */
  	if (cb_pos)
  		list_del(&cb_pos->list);
  	mei_io_cb_free(cb);
  	cl->reading_state = MEI_IDLE;
  	cl->read_cb = NULL;
  out:
  	dev_dbg(&dev->pdev->dev, "end mei read rets= %d\n", rets);
  	mutex_unlock(&dev->device_lock);
  	return rets;
  }
  /**
   * mei_write - the write function.
   *
   * @file: pointer to file structure
   * @ubuf: pointer to user buffer
   * @length: buffer length
   * @offset: data offset in buffer
   *
   * returns >=0 data length on success , <0 on error
   */
  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_device *dev;
  	unsigned long timeout = 0;
  	int rets;
  	int id;
  
  	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;
  	}
  
  	id = mei_me_cl_by_id(dev, cl->me_client_id);
  	if (id < 0) {
  		rets = -ENOTTY;
  		goto out;
  	}
  
  	if (length == 0) {
  		rets = 0;
  		goto out;
  	}
  
  	if (length > dev->me_clients[id].props.max_msg_length) {
  		rets = -EFBIG;
  		goto out;
  	}
  
  	if (cl->state != MEI_FILE_CONNECTED) {
  		dev_err(&dev->pdev->dev, "host client = %d,  is not connected to ME client = %d",
  			cl->host_client_id, cl->me_client_id);
  		rets = -ENODEV;
  		goto out;
  	}
  	if (cl == &dev->iamthif_cl) {
  		write_cb = mei_amthif_find_read_list_entry(dev, file);
  
  		if (write_cb) {
  			timeout = write_cb->read_time +
  				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->list);
  				mei_io_cb_free(write_cb);
  				write_cb = NULL;
  			}
  		}
  	}
  
  	/* free entry used in read */
  	if (cl->reading_state == MEI_READ_COMPLETE) {
  		*offset = 0;
  		write_cb = mei_cl_find_read_cb(cl);
  		if (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;
  		}
  	} else if (cl->reading_state == MEI_IDLE)
  		*offset = 0;
  
  
  	write_cb = mei_io_cb_init(cl, file);
  	if (!write_cb) {
  		dev_err(&dev->pdev->dev, "write cb allocation failed\n");
  		rets = -ENOMEM;
  		goto out;
  	}
  	rets = mei_io_cb_alloc_req_buf(write_cb, length);
  	if (rets)
  		goto out;
  
  	rets = copy_from_user(write_cb->request_buffer.data, ubuf, length);
  	if (rets) {
  		dev_dbg(&dev->pdev->dev, "failed to copy data from userland\n");
  		rets = -EFAULT;
  		goto out;
  	}
  
  	if (cl == &dev->iamthif_cl) {
  		rets = mei_amthif_write(dev, write_cb);
  
  		if (rets) {
  			dev_err(&dev->pdev->dev,
  				"amthif write failed with status = %d\n", rets);
  			goto out;
  		}
  		mutex_unlock(&dev->device_lock);
  		return length;
  	}
  
  	rets = mei_cl_write(cl, write_cb, false);
  out:
  	mutex_unlock(&dev->device_lock);
  	if (rets < 0)
  		mei_io_cb_free(write_cb);
  	return rets;
  }
  
  /**
   * mei_ioctl_connect_client - the connect to fw client IOCTL function
   *
   * @dev: the device structure
   * @data: IOCTL connect data, input and output parameters
   * @file: private data of the file object
   *
   * Locking: called under "dev->device_lock" lock
   *
   * returns 0 on success, <0 on failure.
   */
  static int mei_ioctl_connect_client(struct file *file,
  			struct mei_connect_client_data *data)
  {
  	struct mei_device *dev;
  	struct mei_client *client;
  	struct mei_cl *cl;
  	int i;
  	int rets;
  
  	cl = file->private_data;
  	if (WARN_ON(!cl || !cl->dev))
  		return -ENODEV;
  
  	dev = cl->dev;
  
  	if (dev->dev_state != MEI_DEV_ENABLED) {
  		rets = -ENODEV;
  		goto end;
  	}
  
  	if (cl->state != MEI_FILE_INITIALIZING &&
  	    cl->state != MEI_FILE_DISCONNECTED) {
  		rets = -EBUSY;
  		goto end;
  	}
  
  	/* find ME client we're trying to connect to */
  	i = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
  	if (i < 0 || dev->me_clients[i].props.fixed_address) {
  		dev_dbg(&dev->pdev->dev, "Cannot connect to FW Client UUID = %pUl\n",
  				&data->in_client_uuid);
  		rets = -ENOTTY;
  		goto end;
  	}
  
  	cl->me_client_id = dev->me_clients[i].client_id;
  
  	dev_dbg(&dev->pdev->dev, "Connect to FW Client ID = %d\n",
  			cl->me_client_id);
  	dev_dbg(&dev->pdev->dev, "FW Client - Protocol Version = %d\n",
  			dev->me_clients[i].props.protocol_version);
  	dev_dbg(&dev->pdev->dev, "FW Client - Max Msg Len = %d\n",
  			dev->me_clients[i].props.max_msg_length);
  
  	/* if we're connecting to amthif client then we will use the
  	 * existing connection
  	 */
  	if (uuid_le_cmp(data->in_client_uuid, mei_amthif_guid) == 0) {
  		dev_dbg(&dev->pdev->dev, "FW Client is amthi\n");
  		if (dev->iamthif_cl.state != MEI_FILE_CONNECTED) {
  			rets = -ENODEV;
  			goto end;
  		}
  		mei_cl_unlink(cl);
  
  		kfree(cl);
  		cl = NULL;
  		dev->iamthif_open_count++;
  		file->private_data = &dev->iamthif_cl;
  
  		client = &data->out_client_properties;
  		client->max_msg_length =
  			dev->me_clients[i].props.max_msg_length;
  		client->protocol_version =
  			dev->me_clients[i].props.protocol_version;
  		rets = dev->iamthif_cl.status;
  
  		goto end;
  	}
  
  
  	/* prepare the output buffer */
  	client = &data->out_client_properties;
  	client->max_msg_length = dev->me_clients[i].props.max_msg_length;
  	client->protocol_version = dev->me_clients[i].props.protocol_version;
  	dev_dbg(&dev->pdev->dev, "Can connect?\n");
  
  
  	rets = mei_cl_connect(cl, file);
  
  end:
  	return rets;
  }
  
  
  /**
   * mei_ioctl - the IOCTL function
   *
   * @file: pointer to file structure
   * @cmd: ioctl command
   * @data: pointer to mei message structure
   *
   * returns 0 on success , <0 on error
   */
  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;
  }
  
  /**
   * mei_compat_ioctl - the compat IOCTL function
   *
   * @file: pointer to file structure
   * @cmd: ioctl command
   * @data: pointer to mei message structure
   *
   * returns 0 on success , <0 on error
   */
  #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
  
  
  /**
   * mei_poll - the poll function
   *
   * @file: pointer to file structure
   * @wait: pointer to poll_table structure
   *
   * returns poll mask
   */
  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 POLLERR;
  
  	dev = cl->dev;
  
  	mutex_lock(&dev->device_lock);
  
  	if (!mei_cl_is_connected(cl)) {
  		mask = POLLERR;
  		goto out;
  	}
  
  	mutex_unlock(&dev->device_lock);
  
  
  	if (cl == &dev->iamthif_cl)
  		return mei_amthif_poll(dev, file, wait);
  
  	poll_wait(file, &cl->tx_wait, wait);
  
  	mutex_lock(&dev->device_lock);
  
  	if (!mei_cl_is_connected(cl)) {
  		mask = POLLERR;
  		goto out;
  	}
  
  	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,
  };
  
  
  int mei_register(struct mei_device *dev)
  {
  	int ret;
  	mei_misc_device.parent = &dev->pdev->dev;
  	ret = misc_register(&mei_misc_device);
  	if (ret)
  		return ret;
  
  	if (mei_dbgfs_register(dev, mei_misc_device.name))
  		dev_err(&dev->pdev->dev, "cannot register debugfs\n");
  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(mei_register);
  
  void mei_deregister(struct mei_device *dev)
  {
  	mei_dbgfs_deregister(dev);
  	misc_deregister(&mei_misc_device);
  	mei_misc_device.parent = NULL;
  }
  EXPORT_SYMBOL_GPL(mei_deregister);
  
  static int __init mei_init(void)
  {
  	return mei_cl_bus_init();
  }
  
  static void __exit mei_exit(void)
  {
  	mei_cl_bus_exit();
  }
  
  module_init(mei_init);
  module_exit(mei_exit);
  
  MODULE_AUTHOR("Intel Corporation");
  MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
  MODULE_LICENSE("GPL v2");
  
  