1// SPDX-License-Identifier: GPL-2.0-only
 2/*
 3 * Copyright (C) 2004 IBM Corporation
 4 * Authors:
 5 * Leendert van Doorn <leendert@watson.ibm.com>
 6 * Dave Safford <safford@watson.ibm.com>
 7 * Reiner Sailer <sailer@watson.ibm.com>
 8 * Kylene Hall <kjhall@us.ibm.com>
 9 *
10 * Copyright (C) 2013 Obsidian Research Corp
11 * Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
12 *
13 * Device file system interface to the TPM
 
 
 
 
 
 
14 */
15#include <linux/slab.h>
16#include "tpm-dev.h"
17
18static int tpm_open(struct inode *inode, struct file *file)
19{
20	struct tpm_chip *chip;
21	struct file_priv *priv;
22
23	chip = container_of(inode->i_cdev, struct tpm_chip, cdev);
24
25	/* It's assured that the chip will be opened just once,
26	 * by the check of is_open variable, which is protected
27	 * by driver_lock. */
28	if (test_and_set_bit(0, &chip->is_open)) {
29		dev_dbg(&chip->dev, "Another process owns this TPM\n");
30		return -EBUSY;
31	}
32
33	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
34	if (priv == NULL)
35		goto out;
36
37	tpm_common_open(file, chip, priv, NULL);
38
39	return 0;
40
41 out:
42	clear_bit(0, &chip->is_open);
43	return -ENOMEM;
44}
45
 
 
 
 
 
 
46/*
47 * Called on file close
48 */
49static int tpm_release(struct inode *inode, struct file *file)
50{
51	struct file_priv *priv = file->private_data;
52
53	tpm_common_release(file, priv);
54	clear_bit(0, &priv->chip->is_open);
55	kfree(priv);
56
57	return 0;
58}
59
60const struct file_operations tpm_fops = {
61	.owner = THIS_MODULE,
62	.llseek = no_llseek,
63	.open = tpm_open,
64	.read = tpm_common_read,
65	.write = tpm_common_write,
66	.poll = tpm_common_poll,
67	.release = tpm_release,
68};

 
 1/*
 2 * Copyright (C) 2004 IBM Corporation
 3 * Authors:
 4 * Leendert van Doorn <leendert@watson.ibm.com>
 5 * Dave Safford <safford@watson.ibm.com>
 6 * Reiner Sailer <sailer@watson.ibm.com>
 7 * Kylene Hall <kjhall@us.ibm.com>
 8 *
 9 * Copyright (C) 2013 Obsidian Research Corp
10 * Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
11 *
12 * Device file system interface to the TPM
13 *
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License as
16 * published by the Free Software Foundation, version 2 of the
17 * License.
18 *
19 */
20#include <linux/slab.h>
21#include "tpm-dev.h"
22
23static int tpm_open(struct inode *inode, struct file *file)
24{
25	struct tpm_chip *chip;
26	struct file_priv *priv;
27
28	chip = container_of(inode->i_cdev, struct tpm_chip, cdev);
29
30	/* It's assured that the chip will be opened just once,
31	 * by the check of is_open variable, which is protected
32	 * by driver_lock. */
33	if (test_and_set_bit(0, &chip->is_open)) {
34		dev_dbg(&chip->dev, "Another process owns this TPM\n");
35		return -EBUSY;
36	}
37
38	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
39	if (priv == NULL)
40		goto out;
41
42	tpm_common_open(file, chip, priv);
43
44	return 0;
45
46 out:
47	clear_bit(0, &chip->is_open);
48	return -ENOMEM;
49}
50
51static ssize_t tpm_write(struct file *file, const char __user *buf,
52			 size_t size, loff_t *off)
53{
54	return tpm_common_write(file, buf, size, off, NULL);
55}
56
57/*
58 * Called on file close
59 */
60static int tpm_release(struct inode *inode, struct file *file)
61{
62	struct file_priv *priv = file->private_data;
63
64	tpm_common_release(file, priv);
65	clear_bit(0, &priv->chip->is_open);
66	kfree(priv);
67
68	return 0;
69}
70
71const struct file_operations tpm_fops = {
72	.owner = THIS_MODULE,
73	.llseek = no_llseek,
74	.open = tpm_open,
75	.read = tpm_common_read,
76	.write = tpm_write,
 
77	.release = tpm_release,
78};