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/*
* Copyright (C) 2004 IBM Corporation
* Authors:
* Leendert van Doorn <leendert@watson.ibm.com>
* Dave Safford <safford@watson.ibm.com>
* Reiner Sailer <sailer@watson.ibm.com>
* Kylene Hall <kjhall@us.ibm.com>
*
* Copyright (C) 2013 Obsidian Research Corp
* Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
*
* Device file system interface to the TPM
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2 of the
* License.
*
*/
#include <linux/slab.h>
#include "tpm-dev.h"
static int tpm_open(struct inode *inode, struct file *file)
{
struct tpm_chip *chip;
struct file_priv *priv;
chip = container_of(inode->i_cdev, struct tpm_chip, cdev);
/* It's assured that the chip will be opened just once,
* by the check of is_open variable, which is protected
* by driver_lock. */
if (test_and_set_bit(0, &chip->is_open)) {
dev_dbg(&chip->dev, "Another process owns this TPM\n");
return -EBUSY;
}
priv = kzalloc(sizeof(*priv), GFP_KERNEL);
if (priv == NULL)
goto out;
tpm_common_open(file, chip, priv);
return 0;
out:
clear_bit(0, &chip->is_open);
return -ENOMEM;
}
static ssize_t tpm_write(struct file *file, const char __user *buf,
size_t size, loff_t *off)
{
return tpm_common_write(file, buf, size, off, NULL);
}
/*
* Called on file close
*/
static int tpm_release(struct inode *inode, struct file *file)
{
struct file_priv *priv = file->private_data;
tpm_common_release(file, priv);
clear_bit(0, &priv->chip->is_open);
kfree(priv);
return 0;
}
const struct file_operations tpm_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.open = tpm_open,
.read = tpm_common_read,
.write = tpm_write,
.release = tpm_release,
};
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