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