tpm: Make tpm-dev allocate a per-file structure

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>
Reviewed-by: Joel Schopp <jschopp@linux.vnet.ibm.com>
Reviewed-by: Ashley Lai <adlai@linux.vnet.ibm.com>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>

2 files changed, 57 insertions, 50 deletions

diff --git a/drivers/char/tpm/tpm-dev.c b/drivers/char/tpm/tpm-dev.c
index 4f0cf2b6fc67..d9b774e02a1f 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 7b0a46e214c5..e4d0888d2eab 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;