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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /drivers/char/tpm/tpm-dev.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/char/tpm/tpm-dev.c')
-rw-r--r--drivers/char/tpm/tpm-dev.c78
1 files changed, 78 insertions, 0 deletions
diff --git a/drivers/char/tpm/tpm-dev.c b/drivers/char/tpm/tpm-dev.c
new file mode 100644
index 000000000..ebd74ab5a
--- /dev/null
+++ b/drivers/char/tpm/tpm-dev.c
@@ -0,0 +1,78 @@
+/*
+ * 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,
+};