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Subject[PATCH 13/13] tpm: Make tpm-dev allocate a per-file structure
Date
This consolidates everything that is only used within tpm-dev.c
into tpm-dev.c and out of the publicly visible struct tpm_chip.

The per-file allocation lays the ground work for someday fixing the
strange forced O_EXCL behaviour of the current code.

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
---
drivers/char/tpm/tpm-dev.c | 100 ++++++++++++++++++++++++++-------------------
drivers/char/tpm/tpm.h | 7 ----
2 files changed, 57 insertions(+), 50 deletions(-)

diff --git a/drivers/char/tpm/tpm-dev.c b/drivers/char/tpm/tpm-dev.c
index 8d94e97..f492eb6 100644
--- a/drivers/char/tpm/tpm-dev.c
+++ b/drivers/char/tpm/tpm-dev.c
@@ -22,21 +22,34 @@
#include <linux/uaccess.h>
#include "tpm.h"

+struct file_priv {
+ struct tpm_chip *chip;
+
+ /* Data passed to and from the tpm via the read/write calls */
+ atomic_t data_pending;
+ struct mutex buffer_mutex;
+
+ struct timer_list user_read_timer; /* user needs to claim result */
+ struct work_struct work;
+
+ u8 data_buffer[TPM_BUFSIZE];
+};
+
static void user_reader_timeout(unsigned long ptr)
{
- struct tpm_chip *chip = (struct tpm_chip *) ptr;
+ struct file_priv *priv = (struct file_priv *)ptr;

- schedule_work(&chip->work);
+ schedule_work(&priv->work);
}

static void timeout_work(struct work_struct *work)
{
- struct tpm_chip *chip = container_of(work, struct tpm_chip, work);
+ struct file_priv *priv = container_of(work, struct file_priv, work);

- mutex_lock(&chip->buffer_mutex);
- atomic_set(&chip->data_pending, 0);
- memset(chip->data_buffer, 0, TPM_BUFSIZE);
- mutex_unlock(&chip->buffer_mutex);
+ 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);
}

static int tpm_open(struct inode *inode, struct file *file)
@@ -44,6 +57,7 @@ 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);
+ struct file_priv *priv;

/* It's assured that the chip will be opened just once,
* by the check of is_open variable, which is protected
@@ -53,15 +67,20 @@ static int tpm_open(struct inode *inode, struct file *file)
return -EBUSY;
}

- chip->data_buffer = kzalloc(TPM_BUFSIZE, GFP_KERNEL);
- if (chip->data_buffer == NULL) {
+ priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+ if (priv == NULL) {
clear_bit(0, &chip->is_open);
return -ENOMEM;
}

- atomic_set(&chip->data_pending, 0);
+ 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 = chip;
+ file->private_data = priv;
get_device(chip->dev);
return 0;
}
@@ -69,28 +88,28 @@ static int tpm_open(struct inode *inode, struct file *file)
static ssize_t tpm_read(struct file *file, char __user *buf,
size_t size, loff_t *off)
{
- struct tpm_chip *chip = file->private_data;
+ struct file_priv *priv = 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);
+ 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 */
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);
+ 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(&chip->buffer_mutex);
+ mutex_unlock(&priv->buffer_mutex);
}

- atomic_set(&chip->data_pending, 0);
+ atomic_set(&priv->data_pending, 0);

return ret_size;
}
@@ -98,7 +117,7 @@ static ssize_t tpm_read(struct file *file, char __user *buf,
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;
+ struct file_priv *priv = file->private_data;
size_t in_size = size;
ssize_t out_size;

@@ -106,32 +125,33 @@ static ssize_t tpm_write(struct file *file, const char __user *buf,
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)
+ if (atomic_read(&priv->data_pending) != 0)
return -EBUSY;

if (in_size > TPM_BUFSIZE)
return -E2BIG;

- mutex_lock(&chip->buffer_mutex);
+ mutex_lock(&priv->buffer_mutex);

if (copy_from_user
- (chip->data_buffer, (void __user *) buf, in_size)) {
- mutex_unlock(&chip->buffer_mutex);
+ (priv->data_buffer, (void __user *) buf, in_size)) {
+ mutex_unlock(&priv->buffer_mutex);
return -EFAULT;
}

/* atomic tpm command send and result receive */
- out_size = tpm_transmit(chip, chip->data_buffer, TPM_BUFSIZE);
+ out_size = tpm_transmit(priv->chip, priv->data_buffer,
+ sizeof(priv->data_buffer));
if (out_size < 0) {
- mutex_unlock(&chip->buffer_mutex);
+ mutex_unlock(&priv->buffer_mutex);
return out_size;
}

- atomic_set(&chip->data_pending, out_size);
- mutex_unlock(&chip->buffer_mutex);
+ 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(&chip->user_read_timer, jiffies + (60 * HZ));
+ mod_timer(&priv->user_read_timer, jiffies + (60 * HZ));

return in_size;
}
@@ -141,15 +161,15 @@ static ssize_t tpm_write(struct file *file, const char __user *buf,
*/
static int tpm_release(struct inode *inode, struct file *file)
{
- struct tpm_chip *chip = file->private_data;
+ struct file_priv *priv = file->private_data;

- del_singleshot_timer_sync(&chip->user_read_timer);
- flush_work(&chip->work);
+ del_singleshot_timer_sync(&priv->user_read_timer);
+ flush_work(&priv->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);
+ atomic_set(&priv->data_pending, 0);
+ clear_bit(0, &priv->chip->is_open);
+ put_device(priv->chip->dev);
+ kfree(priv);
return 0;
}

@@ -166,12 +186,6 @@ 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;
diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
index 7b0a46e..e4d0888 100644
--- a/drivers/char/tpm/tpm.h
+++ b/drivers/char/tpm/tpm.h
@@ -103,13 +103,6 @@ struct tpm_chip {
unsigned long is_open; /* only one allowed */
int time_expired;

- /* Data passed to and from the tpm via the read/write calls */
- u8 *data_buffer;
- atomic_t data_pending;
- struct mutex buffer_mutex;
-
- struct timer_list user_read_timer; /* user needs to claim result */
- struct work_struct work;
struct mutex tpm_mutex; /* tpm is processing */

struct tpm_vendor_specific vendor;
--
1.8.1.2


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