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