tpm: Pull everything related to /dev/tpmX into tpm-dev.c
CLASS-dev.c is a common idiom for Linux subsystems
This pulls all the code related to the miscdev into tpm-dev.c and makes it
static. The identical file_operation structs in the drivers are purged and the
tpm common code unconditionally creates the miscdev.
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Joel Schopp <jschopp@linux.vnet.ibm.com>
Reviewed-by: Ashley Lai <adlai@linux.vnet.ibm.com>
[phuewe:
tpm_dev_release is now used only in this file, thus the EXPORT_SYMBOL
can be dropped and the function be marked as static.
It has no other in-kernel users]
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
diff --git a/drivers/char/tpm/tpm-dev.c b/drivers/char/tpm/tpm-dev.c
new file mode 100644
index 0000000..4f0cf2b
--- /dev/null
+++ b/drivers/char/tpm/tpm-dev.c
@@ -0,0 +1,199 @@
+/*
+ * 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/miscdevice.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include "tpm.h"
+
+static void user_reader_timeout(unsigned long ptr)
+{
+ struct tpm_chip *chip = (struct tpm_chip *) ptr;
+
+ schedule_work(&chip->work);
+}
+
+static void timeout_work(struct work_struct *work)
+{
+ struct tpm_chip *chip = container_of(work, struct tpm_chip, work);
+
+ mutex_lock(&chip->buffer_mutex);
+ atomic_set(&chip->data_pending, 0);
+ memset(chip->data_buffer, 0, TPM_BUFSIZE);
+ mutex_unlock(&chip->buffer_mutex);
+}
+
+static int tpm_open(struct inode *inode, struct file *file)
+{
+ struct miscdevice *misc = file->private_data;
+ struct tpm_chip *chip = container_of(misc, struct tpm_chip,
+ vendor.miscdev);
+
+ /* 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;
+ }
+
+ chip->data_buffer = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
+ if (chip->data_buffer == NULL) {
+ clear_bit(0, &chip->is_open);
+ return -ENOMEM;
+ }
+
+ atomic_set(&chip->data_pending, 0);
+
+ file->private_data = chip;
+ get_device(chip->dev);
+ return 0;
+}
+
+static ssize_t tpm_read(struct file *file, char __user *buf,
+ size_t size, loff_t *off)
+{
+ struct tpm_chip *chip = file->private_data;
+ ssize_t ret_size;
+ int rc;
+
+ del_singleshot_timer_sync(&chip->user_read_timer);
+ flush_work(&chip->work);
+ ret_size = atomic_read(&chip->data_pending);
+ if (ret_size > 0) { /* relay data */
+ ssize_t orig_ret_size = ret_size;
+ if (size < ret_size)
+ ret_size = size;
+
+ mutex_lock(&chip->buffer_mutex);
+ rc = copy_to_user(buf, chip->data_buffer, ret_size);
+ memset(chip->data_buffer, 0, orig_ret_size);
+ if (rc)
+ ret_size = -EFAULT;
+
+ mutex_unlock(&chip->buffer_mutex);
+ }
+
+ atomic_set(&chip->data_pending, 0);
+
+ return ret_size;
+}
+
+static ssize_t tpm_write(struct file *file, const char __user *buf,
+ size_t size, loff_t *off)
+{
+ struct tpm_chip *chip = file->private_data;
+ size_t in_size = size;
+ ssize_t out_size;
+
+ /* cannot perform a write until the read has cleared
+ either via tpm_read or a user_read_timer timeout.
+ This also prevents splitted buffered writes from blocking here.
+ */
+ if (atomic_read(&chip->data_pending) != 0)
+ return -EBUSY;
+
+ if (in_size > TPM_BUFSIZE)
+ return -E2BIG;
+
+ mutex_lock(&chip->buffer_mutex);
+
+ if (copy_from_user
+ (chip->data_buffer, (void __user *) buf, in_size)) {
+ mutex_unlock(&chip->buffer_mutex);
+ return -EFAULT;
+ }
+
+ /* atomic tpm command send and result receive */
+ out_size = tpm_transmit(chip, chip->data_buffer, TPM_BUFSIZE);
+ if (out_size < 0) {
+ mutex_unlock(&chip->buffer_mutex);
+ return out_size;
+ }
+
+ atomic_set(&chip->data_pending, out_size);
+ mutex_unlock(&chip->buffer_mutex);
+
+ /* Set a timeout by which the reader must come claim the result */
+ mod_timer(&chip->user_read_timer, jiffies + (60 * HZ));
+
+ return in_size;
+}
+
+/*
+ * Called on file close
+ */
+static int tpm_release(struct inode *inode, struct file *file)
+{
+ struct tpm_chip *chip = file->private_data;
+
+ del_singleshot_timer_sync(&chip->user_read_timer);
+ flush_work(&chip->work);
+ file->private_data = NULL;
+ atomic_set(&chip->data_pending, 0);
+ kzfree(chip->data_buffer);
+ clear_bit(0, &chip->is_open);
+ put_device(chip->dev);
+ return 0;
+}
+
+static const struct file_operations tpm_fops = {
+ .owner = THIS_MODULE,
+ .llseek = no_llseek,
+ .open = tpm_open,
+ .read = tpm_read,
+ .write = tpm_write,
+ .release = tpm_release,
+};
+
+int tpm_dev_add_device(struct tpm_chip *chip)
+{
+ int rc;
+
+ mutex_init(&chip->buffer_mutex);
+ INIT_WORK(&chip->work, timeout_work);
+
+ setup_timer(&chip->user_read_timer, user_reader_timeout,
+ (unsigned long)chip);
+
+ chip->vendor.miscdev.fops = &tpm_fops;
+ if (chip->dev_num == 0)
+ chip->vendor.miscdev.minor = TPM_MINOR;
+ else
+ chip->vendor.miscdev.minor = MISC_DYNAMIC_MINOR;
+
+ chip->vendor.miscdev.name = chip->devname;
+ chip->vendor.miscdev.parent = chip->dev;
+
+ rc = misc_register(&chip->vendor.miscdev);
+ if (rc) {
+ chip->vendor.miscdev.name = NULL;
+ dev_err(chip->dev,
+ "unable to misc_register %s, minor %d err=%d\n",
+ chip->vendor.miscdev.name,
+ chip->vendor.miscdev.minor, rc);
+ }
+ return rc;
+}
+
+void tpm_dev_del_device(struct tpm_chip *chip)
+{
+ if (chip->vendor.miscdev.name)
+ misc_deregister(&chip->vendor.miscdev);
+}
