From ecb38e2f521b01f0fd0b0a3261921b0bcc002dd0 Mon Sep 17 00:00:00 2001 From: James Bottomley Date: Tue, 10 Jan 2017 19:08:53 -0800 Subject: tpm: split out tpm-dev.c into tpm-dev.c and tpm-common-dev.c Signed-off-by: James Bottomley Tested-by: Jarkko Sakkinen Reviewed-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm-dev-common.c | 148 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 148 insertions(+) create mode 100644 drivers/char/tpm/tpm-dev-common.c (limited to 'drivers/char/tpm/tpm-dev-common.c') diff --git a/drivers/char/tpm/tpm-dev-common.c b/drivers/char/tpm/tpm-dev-common.c new file mode 100644 index 000000000000..610638a80383 --- /dev/null +++ b/drivers/char/tpm/tpm-dev-common.c @@ -0,0 +1,148 @@ +/* + * Copyright (C) 2004 IBM Corporation + * Authors: + * Leendert van Doorn + * Dave Safford + * Reiner Sailer + * Kylene Hall + * + * Copyright (C) 2013 Obsidian Research Corp + * Jason Gunthorpe + * + * 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 +#include +#include "tpm.h" +#include "tpm-dev.h" + +static void user_reader_timeout(unsigned long ptr) +{ + struct file_priv *priv = (struct file_priv *)ptr; + + pr_warn("TPM user space timeout is deprecated (pid=%d)\n", + task_tgid_nr(current)); + + schedule_work(&priv->work); +} + +static void timeout_work(struct work_struct *work) +{ + struct file_priv *priv = container_of(work, struct file_priv, work); + + mutex_lock(&priv->buffer_mutex); + atomic_set(&priv->data_pending, 0); + memset(priv->data_buffer, 0, sizeof(priv->data_buffer)); + mutex_unlock(&priv->buffer_mutex); +} + +void tpm_common_open(struct file *file, struct tpm_chip *chip, + struct file_priv *priv) +{ + priv->chip = chip; + atomic_set(&priv->data_pending, 0); + mutex_init(&priv->buffer_mutex); + setup_timer(&priv->user_read_timer, user_reader_timeout, + (unsigned long)priv); + INIT_WORK(&priv->work, timeout_work); + + file->private_data = priv; +} + +ssize_t tpm_common_read(struct file *file, char __user *buf, + size_t size, loff_t *off) +{ + struct file_priv *priv = file->private_data; + ssize_t ret_size; + ssize_t orig_ret_size; + int rc; + + del_singleshot_timer_sync(&priv->user_read_timer); + flush_work(&priv->work); + ret_size = atomic_read(&priv->data_pending); + if (ret_size > 0) { /* relay data */ + orig_ret_size = ret_size; + if (size < ret_size) + ret_size = size; + + mutex_lock(&priv->buffer_mutex); + rc = copy_to_user(buf, priv->data_buffer, ret_size); + memset(priv->data_buffer, 0, orig_ret_size); + if (rc) + ret_size = -EFAULT; + + mutex_unlock(&priv->buffer_mutex); + } + + atomic_set(&priv->data_pending, 0); + + return ret_size; +} + +ssize_t tpm_common_write(struct file *file, const char __user *buf, + size_t size, loff_t *off, struct tpm_space *space) +{ + struct file_priv *priv = 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 split + * buffered writes from blocking here. + */ + if (atomic_read(&priv->data_pending) != 0) + return -EBUSY; + + if (in_size > TPM_BUFSIZE) + return -E2BIG; + + mutex_lock(&priv->buffer_mutex); + + if (copy_from_user + (priv->data_buffer, (void __user *) buf, in_size)) { + mutex_unlock(&priv->buffer_mutex); + return -EFAULT; + } + + /* atomic tpm command send and result receive. We only hold the ops + * lock during this period so that the tpm can be unregistered even if + * the char dev is held open. + */ + if (tpm_try_get_ops(priv->chip)) { + mutex_unlock(&priv->buffer_mutex); + return -EPIPE; + } + out_size = tpm_transmit(priv->chip, space, priv->data_buffer, + sizeof(priv->data_buffer), 0); + + tpm_put_ops(priv->chip); + if (out_size < 0) { + mutex_unlock(&priv->buffer_mutex); + return out_size; + } + + atomic_set(&priv->data_pending, out_size); + mutex_unlock(&priv->buffer_mutex); + + /* Set a timeout by which the reader must come claim the result */ + mod_timer(&priv->user_read_timer, jiffies + (120 * HZ)); + + return in_size; +} + +/* + * Called on file close + */ +void tpm_common_release(struct file *file, struct file_priv *priv) +{ + del_singleshot_timer_sync(&priv->user_read_timer); + flush_work(&priv->work); + file->private_data = NULL; + atomic_set(&priv->data_pending, 0); +} -- cgit v1.2.3