/*
* Device file system interface to the TPM
+ *
+ * It's assured that the chip will be opened just once,
+ * by the check of is_open variable, which is protected
+ * by driver_lock.
*/
int tpm_open(struct inode *inode, struct file *file)
{
int rc = 0, minor = iminor(inode);
struct tpm_chip *chip = NULL, *pos;
- lock_kernel();
spin_lock(&driver_lock);
list_for_each_entry(pos, &tpm_chip_list, list) {
if (chip->data_buffer == NULL) {
chip->num_opens--;
put_device(chip->dev);
- unlock_kernel();
return -ENOMEM;
}
atomic_set(&chip->data_pending, 0);
file->private_data = chip;
- unlock_kernel();
return 0;
err_out:
spin_unlock(&driver_lock);
- unlock_kernel();
return rc;
}
EXPORT_SYMBOL_GPL(tpm_open);