drivers/amlogic/dvb/dsm/aml_dsm.c - manifest_repos/kernel - Git at Google

 // SPDX-License-Identifier: (GPL-2.0+ OR MIT)
 /*
  * Copyright (c) 2019 Amlogic, Inc. All rights reserved.
  */

 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/fs.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/platform_device.h>
 #include <linux/types.h>
 #include <linux/cdev.h>
 #include <linux/uaccess.h>
 #include <linux/list.h>
 #include <linux/mutex.h>
 #include <linux/compat.h>
 #include "aml_dsm.h"

 #define DEVICE_NAME "aml_dsm"
 #define DEVICE_CLASS_NAME "aml_dsm"

 struct dev_session;
 struct dsm_session;
 struct keytable_key;

 enum {
 	DSM_ROLE_OWNER = 1,
 	DSM_ROLE_CLIENT
 };

 /**
  * struct dev_session
  * @dsm: pointer to dsm session data
  * @role: dsm session role
  */
 struct dev_session {
 	struct dsm_session *dsm;
 	int role;
 };

 /**
  * struct dsm_session
  * @list: sessions list
  * @ref_count: reference counter
  * @key_count: key counter
  * @token: unique token
  * @properties: @properties
  * @lock: session lock
  * @keys: dscrambler keys
  */
 struct dsm_session {
 	struct list_head list;
 	atomic_t ref_count;
 	atomic_t key_count;
 	__u32 token;
 	__u32 properties[MAX_DSM_PROP];
 	struct mutex lock; /*session lock*/
 	struct list_head keys;
 };

 /**
  * struct keytable_key
  * @list: keys list
  * id: keyslot index id
  * @type: keyslot type
  */
 struct keytable_key {
 	struct list_head list;
 	__u32 id;
 	__u32 parity;
 	__u32 algo;
 	__u32 is_iv;
 	__u32 is_enc;
 };

 static int debug = 1;
 static struct list_head sessions_head;
 static DEFINE_MUTEX(sessions_lock);
 static dev_t dsm_devno;
 static struct cdev *dsm_cdev;
 static struct class *dsm_class;

 module_param(debug, int, 0644);

 static struct dsm_session *dsm_find_session_by_token(__u32 token)
 {
 	struct dsm_session *sess = NULL;
 	struct list_head *pos, *tmp;

 	list_for_each_safe(pos, tmp, &sessions_head) {
 		sess = list_entry(pos, struct dsm_session, list);
 		if (sess->token == token)
 			return sess;
 	}
 	return NULL;
 }

 static struct keytable_key *dsm_find_keyslot_by_id(struct dsm_session *sess,
 						      __u32 id)
 {
 	struct keytable_key *key = NULL;
 	struct list_head *pos, *tmp;

 	list_for_each_safe(pos, tmp, &sess->keys) {
 		key = list_entry(pos, struct keytable_key, list);
 		if (key->id == id)
 			return key;
 	}
 	return NULL;
 }

 static long dsm_open_session(struct dev_session *dev,
 				union dsm_para *para)
 {
 	struct dsm_session *sess = NULL;

 	if (dev->dsm)
 		return -EADDRINUSE;
 	/**
 	 * Do not allow prefix or mask in low 16 bits
 	 */
 	if ((para->session.prefix & 0xFFFF) ||
 			(para->session.mask & 0xFFFF))
 		return -EINVAL;

 	sess = kzalloc(sizeof(*sess), GFP_KERNEL);
 	if (!sess)
 		return -ENOMEM;

 	atomic_set(&sess->ref_count, 1);
 	atomic_set(&sess->key_count, 0);
 	INIT_LIST_HEAD(&sess->keys);
 	mutex_init(&sess->lock);

 	mutex_lock(&sessions_lock);
 	do {
 		get_random_bytes(&sess->token, sizeof(sess->token));
 		sess->token = para->session.prefix
 				| (sess->token & (~para->session.mask));
 	} while (dsm_find_session_by_token(sess->token));
 	list_add_tail(&sess->list, &sessions_head);
 	dev->dsm = sess;
 	dev->role = DSM_ROLE_OWNER;
 	para->session.token = sess->token;
 	mutex_unlock(&sessions_lock);
 	return 0;
 }

 static void dsm_close_session(struct dsm_session *sess)
 {
 	struct list_head *pos, *tmp;
 	struct keytable_key *key;

 	if (sess) {
 		mutex_lock(&sess->lock);
 		list_for_each_safe(pos, tmp, &sess->keys) {
 			key = list_entry(pos, struct keytable_key, list);
 			list_del(&key->list);
 			kfree(key);
 		}
 		mutex_unlock(&sess->lock);
 	}
 }

 static void dsm_unref_session(struct dev_session *dev)
 {
 	struct dsm_session *sess = dev->dsm;

 	mutex_lock(&sessions_lock);
 	if (sess) {
 		if (atomic_sub_and_test(1, &sess->ref_count)) {
 			dsm_close_session(sess);
 			list_del(&sess->list);
 			kfree(sess);
 			dev->dsm = NULL;
 		}
 	}
 	mutex_unlock(&sessions_lock);
 }

 static long dsm_add_keyslot(struct dev_session *dev, union dsm_para *para)
 {
 	long r = 0;
 	struct keytable_key *key;
 	struct dsm_session *sess = dev->dsm;

 	if (!sess)
 		return -EBADFD;

 	if (dev->role != DSM_ROLE_OWNER)
 		return -EPERM;

 	key = kzalloc(sizeof(*key), GFP_KERNEL);
 	if (!key)
 		return -ENOMEM;

 	mutex_lock(&sess->lock);
 	if (dsm_find_keyslot_by_id(sess, para->keyslot.id)) {
 		kfree(key);
 		r = -EEXIST;
 	} else if (atomic_read(&sess->key_count) >= MAX_KEYSLOTS) {
 		kfree(key);
 		r = -EOVERFLOW;
 	} else {
 		key->id = para->keyslot.id;
 		key->parity = para->keyslot.parity;
 		key->algo = para->keyslot.algo;
 		key->is_iv = para->keyslot.is_iv;
 		key->is_enc = para->keyslot.is_enc;
 		list_add_tail(&key->list, &sess->keys);
 		atomic_inc(&sess->key_count);
 	}
 	mutex_unlock(&sess->lock);
 	return r;
 }

 static long dsm_del_keyslot(struct dev_session *dev, union dsm_para *para)
 {
 	long r = -ENOKEY;
 	struct dsm_session *sess = dev->dsm;
 	struct keytable_key *key;

 	if (!sess)
 		return -EBADFD;

 	if (dev->role != DSM_ROLE_OWNER)
 		return -EPERM;

 	mutex_lock(&sess->lock);
 	key = dsm_find_keyslot_by_id(sess, para->keyslot.id);
 	if (key) {
 		list_del(&key->list);
 		kfree(key);
 		atomic_dec(&sess->key_count);
 		r = 0;
 	}
 	mutex_unlock(&sess->lock);
 	return r;
 }

 static long dsm_set_token(struct dev_session *dev, union dsm_para *para)
 {
 	long r = -ENXIO;
 	struct dsm_session *sess;

 	if (dev->dsm)
 		return -EINVAL;

 	mutex_lock(&sessions_lock);
 	sess = dsm_find_session_by_token(para->session.token);
 	if (sess) {
 		atomic_inc(&sess->ref_count);
 		dev->dsm = sess;
 		dev->role = DSM_ROLE_CLIENT;
 		r = 0;
 	}
 	mutex_unlock(&sessions_lock);
 	return r;
 }

 static long dsm_get_keyslot_list(struct dev_session *dev, union dsm_para *para)
 {
 	struct dsm_session *sess = dev->dsm;
 	__u32 i = 0;
 	struct list_head *pos, *tmp;
 	struct keytable_key *key;

 	if (!sess)
 		return -EINVAL;

 	mutex_lock(&sess->lock);
 	list_for_each_safe(pos, tmp, &sess->keys) {
 		key = list_entry(pos, struct keytable_key, list);
 		para->keyslot_list.keyslots[i].id = key->id;
 		para->keyslot_list.keyslots[i].parity = key->parity;
 		para->keyslot_list.keyslots[i].algo = key->algo;
 		para->keyslot_list.keyslots[i].is_iv = key->is_iv;
 		para->keyslot_list.keyslots[i].is_enc = key->is_enc;
 		i++;
 	}
 	para->keyslot_list.count = atomic_read(&sess->key_count);
 	mutex_unlock(&sess->lock);
 	return 0;
 }

 static long dsm_set_property(struct dev_session *dev, union dsm_para *para)
 {
 	struct dsm_session *sess = dev->dsm;

 	if (!sess)
 		return -EINVAL;

 	if (para->property.key >= MAX_DSM_PROP)
 		return -EINVAL;

 	mutex_lock(&sess->lock);
 	sess->properties[para->property.key] = para->property.value;
 	mutex_unlock(&sess->lock);
 	return 0;
 }

 static long dsm_get_property(struct dev_session *dev, union dsm_para *para)
 {
 	struct dsm_session *sess = dev->dsm;

 	if (!sess)
 		return -EINVAL;

 	if (para->property.key >= MAX_DSM_PROP)
 		return -EINVAL;

 	mutex_lock(&sess->lock);
 	para->property.value = sess->properties[para->property.key];
 	mutex_unlock(&sess->lock);
 	return 0;
 }

 /* ------------------------------------------------------------------
  * File operations for the device
  * ------------------------------------------------------------------
  */
 int dsm_open(struct inode *inode, struct file *filp)
 {
 	struct dev_session *dev = NULL;

 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
 	if (!dev)
 		return -ENOMEM;

 	filp->private_data = dev;
 	return 0;
 }

 int dsm_close(struct inode *inode, struct file *filp)
 {
 	struct dev_session *dev;

 	dev = filp->private_data;
 	if (dev) {
 		dsm_unref_session(dev);
 		filp->private_data = NULL;
 		kfree(dev);
 	}
 	return 0;
 }

 long dsm_ioctl(struct file *filp, unsigned int cmd, unsigned long userdata)
 {
 	long retval = 0;
 	struct dev_session *dev = NULL;
 	union dsm_para __user *argp = (void __user *)userdata;
 	union dsm_para para;

 	if (_IOC_TYPE(cmd) != DSM_IOC_MAGIC)
 		return -EINVAL;

 	dev = filp->private_data;
 	if (!dev)
 		return -EINVAL;

 	if (copy_from_user((void *)&para, argp, sizeof(para)))
 		return -EINVAL;

 	switch (cmd) {
 	case DSM_IOC_OPEN_SESSION:
 		retval = dsm_open_session(dev, &para);
 		break;
 	case DSM_IOC_ADD_KEYSLOT:
 		retval = dsm_add_keyslot(dev, &para);
 		break;
 	case DSM_IOC_DEL_KEYSLOT:
 		retval = dsm_del_keyslot(dev, &para);
 		break;
 	case DSM_IOC_SET_TOKEN:
 		retval = dsm_set_token(dev, &para);
 		break;
 	case DSM_IOC_GET_KEYSLOT_LIST:
 		retval = dsm_get_keyslot_list(dev, &para);
 		break;
 	case DSM_IOC_SET_PROPERTY:
 		retval = dsm_set_property(dev, &para);
 		break;
 	case DSM_IOC_GET_PROPERTY:
 		retval = dsm_get_property(dev, &para);
 		break;
 	default:
 		retval = -EINVAL;
 		break;
 	}
 	if (copy_to_user((void *)argp, &para, sizeof(para)))
 		return -EFAULT;

 	return retval;
 }

 #ifdef CONFIG_COMPAT
 static long dsm_compat_ioctl(struct file *file, unsigned int cmd, ulong arg)
 {
 	long ret = 0;

 	ret = dsm_ioctl(file, cmd, (ulong)compat_ptr(arg));
 	return ret;
 }
 #endif

 const struct file_operations dsm_fops = {
 	.owner = THIS_MODULE,
 	.open = dsm_open,
 	.release = dsm_close,
 	.unlocked_ioctl = dsm_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = dsm_compat_ioctl,
 #endif
 };

 /* -----------------------------------------------------------------
  * Initialization and module stuff
  * -----------------------------------------------------------------
  */

 #define APPEND_ATTR_BUF(format, args...) { \
 	size += snprintf(buf + size, PAGE_SIZE - size, format, args); \
 }

 static ssize_t usage_show(struct class *class,
 			  struct class_attribute *attr, char *buf)
 {
 	struct list_head *pos1, *tmp1;
 	struct list_head *pos2, *tmp2;
 	struct dsm_session *sess;
 	struct keytable_key *key;
 	ssize_t size = 0;

 	mutex_lock(&sessions_lock);
 	list_for_each_safe(pos1, tmp1, &sessions_head) {
 		sess = list_entry(pos1, struct dsm_session, list);
 		APPEND_ATTR_BUF("Session token: 0x%08x, keyslots: %d\n",
 				sess->token,
 				atomic_read(&sess->key_count))
 		list_for_each_safe(pos2, tmp2, &sess->keys) {
 			key = list_entry(pos2, struct keytable_key, list);
 			APPEND_ATTR_BUF("\tSlot: %2d, ",
 				key->id)
 			APPEND_ATTR_BUF("parity: 0x%x, algo: %d, ",
 				key->parity,
 				key->algo)
 			APPEND_ATTR_BUF("is_iv: %d, is_enc: %d\n",
 				key->is_iv,
 				key->is_enc)
 		}
 	}
 	mutex_unlock(&sessions_lock);
 	APPEND_ATTR_BUF("%s", "\n")
 	return size;
 }

 #undef APPEND_ATTR_BUF

 static struct class_attribute dsm_class_attrs[] = {
 	__ATTR_RO(usage),
 	__ATTR_NULL
 };

 static void remove_dsmsub_attrs(struct class *class)
 {
 	int i = 0;

 	for (i = 0; dsm_class_attrs[i].attr.name; i++)
 		class_remove_file(class, &dsm_class_attrs[i]);
 }

 static void create_dsmsub_attrs(struct class *class)
 {
 	int i = 0;

 	for (i = 0; dsm_class_attrs[i].attr.name; i++) {
 		if (class_create_file(class, &dsm_class_attrs[i]) < 0)
 			break;
 	}
 }

 int __init dsm_init(void)
 {
 	int result;
 	struct device *dsm_dev;

 	result = alloc_chrdev_region(&dsm_devno, 0, 1, DEVICE_NAME);

 	if (result < 0) {
 		result = -ENODEV;
 		goto fail0;
 	}

 	dsm_class = class_create(THIS_MODULE, DEVICE_CLASS_NAME);

 	if (IS_ERR(dsm_class)) {
 		result = PTR_ERR(dsm_class);
 		goto fail1;
 	}
 	create_dsmsub_attrs(dsm_class);

 	dsm_cdev = kmalloc(sizeof(*dsm_cdev), GFP_KERNEL);
 	if (!dsm_cdev) {
 		result = -ENOMEM;
 		goto fail2;
 	}
 	cdev_init(dsm_cdev, &dsm_fops);
 	dsm_cdev->owner = THIS_MODULE;
 	result = cdev_add(dsm_cdev, dsm_devno, 1);
 	if (result)
 		goto fail3;

 	dsm_dev = device_create(dsm_class,
 				  NULL, MKDEV(MAJOR(dsm_devno), 0),
 				  NULL, DEVICE_NAME);

 	if (IS_ERR(dsm_dev)) {
 		result = PTR_ERR(dsm_dev);
 		goto fail4;
 	}

 	INIT_LIST_HEAD(&sessions_head);

 	return 0;
 fail4:
 	cdev_del(dsm_cdev);
 fail3:
 	kfree(dsm_cdev);
 fail2:
 	remove_dsmsub_attrs(dsm_class);
 	class_destroy(dsm_class);
 fail1:
 	unregister_chrdev_region(dsm_devno, 1);
 fail0:
 	return result;
 }

 void __exit dsm_exit(void)
 {
 	cdev_del(dsm_cdev);
 	kfree(dsm_cdev);
 	device_destroy(dsm_class, MKDEV(MAJOR(dsm_devno), 0));
 	remove_dsmsub_attrs(dsm_class);
 	class_destroy(dsm_class);
 	unregister_chrdev_region(dsm_devno, 1);
 }

 MODULE_AUTHOR("Tao Guo <tao.guo@amlogic.com>");
 MODULE_DESCRIPTION("Amlogic Descrambler Session Manager Driver");
 MODULE_LICENSE("GPL");

 module_init(dsm_init);
 module_exit(dsm_exit);
	// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
	/*
	* Copyright (c) 2019 Amlogic, Inc. All rights reserved.
	*/

	#include <linux/module.h>
	#include <linux/errno.h>
	#include <linux/fs.h>
	#include <linux/kernel.h>
	#include <linux/slab.h>
	#include <linux/platform_device.h>
	#include <linux/types.h>
	#include <linux/cdev.h>
	#include <linux/uaccess.h>
	#include <linux/list.h>
	#include <linux/mutex.h>
	#include <linux/compat.h>
	#include "aml_dsm.h"

	#define DEVICE_NAME "aml_dsm"
	#define DEVICE_CLASS_NAME "aml_dsm"

	struct dev_session;
	struct dsm_session;
	struct keytable_key;

	enum {
	DSM_ROLE_OWNER = 1,
	DSM_ROLE_CLIENT
	};

	/**
	* struct dev_session
	* @dsm: pointer to dsm session data
	* @role: dsm session role
	*/
	struct dev_session {
	struct dsm_session *dsm;
	int role;
	};

	/**
	* struct dsm_session
	* @list: sessions list
	* @ref_count: reference counter
	* @key_count: key counter
	* @token: unique token
	* @properties: @properties
	* @lock: session lock
	* @keys: dscrambler keys
	*/
	struct dsm_session {
	struct list_head list;
	atomic_t ref_count;
	atomic_t key_count;
	__u32 token;
	__u32 properties[MAX_DSM_PROP];
	struct mutex lock; /session lock/
	struct list_head keys;
	};

	/**
	* struct keytable_key
	* @list: keys list
	* id: keyslot index id
	* @type: keyslot type
	*/
	struct keytable_key {
	struct list_head list;
	__u32 id;
	__u32 parity;
	__u32 algo;
	__u32 is_iv;
	__u32 is_enc;
	};

	static int debug = 1;
	static struct list_head sessions_head;
	static DEFINE_MUTEX(sessions_lock);
	static dev_t dsm_devno;
	static struct cdev *dsm_cdev;
	static struct class *dsm_class;

	module_param(debug, int, 0644);

	static struct dsm_session *dsm_find_session_by_token(__u32 token)
	{
	struct dsm_session *sess = NULL;
	struct list_head pos, tmp;

	list_for_each_safe(pos, tmp, &sessions_head) {
	sess = list_entry(pos, struct dsm_session, list);
	if (sess->token == token)
	return sess;
	}
	return NULL;
	}

	static struct keytable_key dsm_find_keyslot_by_id(struct dsm_session sess,
	__u32 id)
	{
	struct keytable_key *key = NULL;
	struct list_head pos, tmp;

	list_for_each_safe(pos, tmp, &sess->keys) {
	key = list_entry(pos, struct keytable_key, list);
	if (key->id == id)
	return key;
	}
	return NULL;
	}

	static long dsm_open_session(struct dev_session *dev,
	union dsm_para *para)
	{
	struct dsm_session *sess = NULL;

	if (dev->dsm)
	return -EADDRINUSE;
	/**
	* Do not allow prefix or mask in low 16 bits
	*/
	if ((para->session.prefix & 0xFFFF) \|\|
	(para->session.mask & 0xFFFF))
	return -EINVAL;

	sess = kzalloc(sizeof(*sess), GFP_KERNEL);
	if (!sess)
	return -ENOMEM;

	atomic_set(&sess->ref_count, 1);
	atomic_set(&sess->key_count, 0);
	INIT_LIST_HEAD(&sess->keys);
	mutex_init(&sess->lock);

	mutex_lock(&sessions_lock);
	do {
	get_random_bytes(&sess->token, sizeof(sess->token));
	sess->token = para->session.prefix
	\| (sess->token & (~para->session.mask));
	} while (dsm_find_session_by_token(sess->token));
	list_add_tail(&sess->list, &sessions_head);
	dev->dsm = sess;
	dev->role = DSM_ROLE_OWNER;
	para->session.token = sess->token;
	mutex_unlock(&sessions_lock);
	return 0;
	}

	static void dsm_close_session(struct dsm_session *sess)
	{
	struct list_head pos, tmp;
	struct keytable_key *key;

	if (sess) {
	mutex_lock(&sess->lock);
	list_for_each_safe(pos, tmp, &sess->keys) {
	key = list_entry(pos, struct keytable_key, list);
	list_del(&key->list);
	kfree(key);
	}
	mutex_unlock(&sess->lock);
	}
	}

	static void dsm_unref_session(struct dev_session *dev)
	{
	struct dsm_session *sess = dev->dsm;

	mutex_lock(&sessions_lock);
	if (sess) {
	if (atomic_sub_and_test(1, &sess->ref_count)) {
	dsm_close_session(sess);
	list_del(&sess->list);
	kfree(sess);
	dev->dsm = NULL;
	}
	}
	mutex_unlock(&sessions_lock);
	}

	static long dsm_add_keyslot(struct dev_session dev, union dsm_para para)
	{
	long r = 0;
	struct keytable_key *key;
	struct dsm_session *sess = dev->dsm;

	if (!sess)
	return -EBADFD;

	if (dev->role != DSM_ROLE_OWNER)
	return -EPERM;

	key = kzalloc(sizeof(*key), GFP_KERNEL);
	if (!key)
	return -ENOMEM;

	mutex_lock(&sess->lock);
	if (dsm_find_keyslot_by_id(sess, para->keyslot.id)) {
	kfree(key);
	r = -EEXIST;
	} else if (atomic_read(&sess->key_count) >= MAX_KEYSLOTS) {
	kfree(key);
	r = -EOVERFLOW;
	} else {
	key->id = para->keyslot.id;
	key->parity = para->keyslot.parity;
	key->algo = para->keyslot.algo;
	key->is_iv = para->keyslot.is_iv;
	key->is_enc = para->keyslot.is_enc;
	list_add_tail(&key->list, &sess->keys);
	atomic_inc(&sess->key_count);
	}
	mutex_unlock(&sess->lock);
	return r;
	}

	static long dsm_del_keyslot(struct dev_session dev, union dsm_para para)
	{
	long r = -ENOKEY;
	struct dsm_session *sess = dev->dsm;
	struct keytable_key *key;

	if (!sess)
	return -EBADFD;

	if (dev->role != DSM_ROLE_OWNER)
	return -EPERM;

	mutex_lock(&sess->lock);
	key = dsm_find_keyslot_by_id(sess, para->keyslot.id);
	if (key) {
	list_del(&key->list);
	kfree(key);
	atomic_dec(&sess->key_count);
	r = 0;
	}
	mutex_unlock(&sess->lock);
	return r;
	}

	static long dsm_set_token(struct dev_session dev, union dsm_para para)
	{
	long r = -ENXIO;
	struct dsm_session *sess;

	if (dev->dsm)
	return -EINVAL;

	mutex_lock(&sessions_lock);
	sess = dsm_find_session_by_token(para->session.token);
	if (sess) {
	atomic_inc(&sess->ref_count);
	dev->dsm = sess;
	dev->role = DSM_ROLE_CLIENT;
	r = 0;
	}
	mutex_unlock(&sessions_lock);
	return r;
	}

	static long dsm_get_keyslot_list(struct dev_session dev, union dsm_para para)
	{
	struct dsm_session *sess = dev->dsm;
	__u32 i = 0;
	struct list_head pos, tmp;
	struct keytable_key *key;

	if (!sess)
	return -EINVAL;

	mutex_lock(&sess->lock);
	list_for_each_safe(pos, tmp, &sess->keys) {
	key = list_entry(pos, struct keytable_key, list);
	para->keyslot_list.keyslots[i].id = key->id;
	para->keyslot_list.keyslots[i].parity = key->parity;
	para->keyslot_list.keyslots[i].algo = key->algo;
	para->keyslot_list.keyslots[i].is_iv = key->is_iv;
	para->keyslot_list.keyslots[i].is_enc = key->is_enc;
	i++;
	}
	para->keyslot_list.count = atomic_read(&sess->key_count);
	mutex_unlock(&sess->lock);
	return 0;
	}

	static long dsm_set_property(struct dev_session dev, union dsm_para para)
	{
	struct dsm_session *sess = dev->dsm;

	if (!sess)
	return -EINVAL;

	if (para->property.key >= MAX_DSM_PROP)
	return -EINVAL;

	mutex_lock(&sess->lock);
	sess->properties[para->property.key] = para->property.value;
	mutex_unlock(&sess->lock);
	return 0;
	}

	static long dsm_get_property(struct dev_session dev, union dsm_para para)
	{
	struct dsm_session *sess = dev->dsm;

	if (!sess)
	return -EINVAL;

	if (para->property.key >= MAX_DSM_PROP)
	return -EINVAL;

	mutex_lock(&sess->lock);
	para->property.value = sess->properties[para->property.key];
	mutex_unlock(&sess->lock);
	return 0;
	}

	/* ------------------------------------------------------------------
	* File operations for the device
	* ------------------------------------------------------------------
	*/
	int dsm_open(struct inode inode, struct file filp)
	{
	struct dev_session *dev = NULL;

	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
	if (!dev)
	return -ENOMEM;

	filp->private_data = dev;
	return 0;
	}

	int dsm_close(struct inode inode, struct file filp)
	{
	struct dev_session *dev;

	dev = filp->private_data;
	if (dev) {
	dsm_unref_session(dev);
	filp->private_data = NULL;
	kfree(dev);
	}
	return 0;
	}

	long dsm_ioctl(struct file *filp, unsigned int cmd, unsigned long userdata)
	{
	long retval = 0;
	struct dev_session *dev = NULL;
	union dsm_para __user argp = (void __user )userdata;
	union dsm_para para;

	if (_IOC_TYPE(cmd) != DSM_IOC_MAGIC)
	return -EINVAL;

	dev = filp->private_data;
	if (!dev)
	return -EINVAL;

	if (copy_from_user((void *)&para, argp, sizeof(para)))
	return -EINVAL;

	switch (cmd) {
	case DSM_IOC_OPEN_SESSION:
	retval = dsm_open_session(dev, &para);
	break;
	case DSM_IOC_ADD_KEYSLOT:
	retval = dsm_add_keyslot(dev, &para);
	break;
	case DSM_IOC_DEL_KEYSLOT:
	retval = dsm_del_keyslot(dev, &para);
	break;
	case DSM_IOC_SET_TOKEN:
	retval = dsm_set_token(dev, &para);
	break;
	case DSM_IOC_GET_KEYSLOT_LIST:
	retval = dsm_get_keyslot_list(dev, &para);
	break;
	case DSM_IOC_SET_PROPERTY:
	retval = dsm_set_property(dev, &para);
	break;
	case DSM_IOC_GET_PROPERTY:
	retval = dsm_get_property(dev, &para);
	break;
	default:
	retval = -EINVAL;
	break;
	}
	if (copy_to_user((void *)argp, &para, sizeof(para)))
	return -EFAULT;

	return retval;
	}

	#ifdef CONFIG_COMPAT
	static long dsm_compat_ioctl(struct file *file, unsigned int cmd, ulong arg)
	{
	long ret = 0;

	ret = dsm_ioctl(file, cmd, (ulong)compat_ptr(arg));
	return ret;
	}
	#endif

	const struct file_operations dsm_fops = {
	.owner = THIS_MODULE,
	.open = dsm_open,
	.release = dsm_close,
	.unlocked_ioctl = dsm_ioctl,
	#ifdef CONFIG_COMPAT
	.compat_ioctl = dsm_compat_ioctl,
	#endif
	};

	/* -----------------------------------------------------------------
	* Initialization and module stuff
	* -----------------------------------------------------------------
	*/

	#define APPEND_ATTR_BUF(format, args...) { \
	size += snprintf(buf + size, PAGE_SIZE - size, format, args); \
	}

	static ssize_t usage_show(struct class *class,
	struct class_attribute attr, char buf)
	{
	struct list_head pos1, tmp1;
	struct list_head pos2, tmp2;
	struct dsm_session *sess;
	struct keytable_key *key;
	ssize_t size = 0;

	mutex_lock(&sessions_lock);
	list_for_each_safe(pos1, tmp1, &sessions_head) {
	sess = list_entry(pos1, struct dsm_session, list);
	APPEND_ATTR_BUF("Session token: 0x%08x, keyslots: %d\n",
	sess->token,
	atomic_read(&sess->key_count))
	list_for_each_safe(pos2, tmp2, &sess->keys) {
	key = list_entry(pos2, struct keytable_key, list);
	APPEND_ATTR_BUF("\tSlot: %2d, ",
	key->id)
	APPEND_ATTR_BUF("parity: 0x%x, algo: %d, ",
	key->parity,
	key->algo)
	APPEND_ATTR_BUF("is_iv: %d, is_enc: %d\n",
	key->is_iv,
	key->is_enc)
	}
	}
	mutex_unlock(&sessions_lock);
	APPEND_ATTR_BUF("%s", "\n")
	return size;
	}

	#undef APPEND_ATTR_BUF

	static struct class_attribute dsm_class_attrs[] = {
	__ATTR_RO(usage),
	__ATTR_NULL
	};

	static void remove_dsmsub_attrs(struct class *class)
	{
	int i = 0;

	for (i = 0; dsm_class_attrs[i].attr.name; i++)
	class_remove_file(class, &dsm_class_attrs[i]);
	}

	static void create_dsmsub_attrs(struct class *class)
	{
	int i = 0;

	for (i = 0; dsm_class_attrs[i].attr.name; i++) {
	if (class_create_file(class, &dsm_class_attrs[i]) < 0)
	break;
	}
	}

	int __init dsm_init(void)
	{
	int result;
	struct device *dsm_dev;

	result = alloc_chrdev_region(&dsm_devno, 0, 1, DEVICE_NAME);

	if (result < 0) {
	result = -ENODEV;
	goto fail0;
	}

	dsm_class = class_create(THIS_MODULE, DEVICE_CLASS_NAME);

	if (IS_ERR(dsm_class)) {
	result = PTR_ERR(dsm_class);
	goto fail1;
	}
	create_dsmsub_attrs(dsm_class);

	dsm_cdev = kmalloc(sizeof(*dsm_cdev), GFP_KERNEL);
	if (!dsm_cdev) {
	result = -ENOMEM;
	goto fail2;
	}
	cdev_init(dsm_cdev, &dsm_fops);
	dsm_cdev->owner = THIS_MODULE;
	result = cdev_add(dsm_cdev, dsm_devno, 1);
	if (result)
	goto fail3;

	dsm_dev = device_create(dsm_class,
	NULL, MKDEV(MAJOR(dsm_devno), 0),
	NULL, DEVICE_NAME);

	if (IS_ERR(dsm_dev)) {
	result = PTR_ERR(dsm_dev);
	goto fail4;
	}

	INIT_LIST_HEAD(&sessions_head);

	return 0;
	fail4:
	cdev_del(dsm_cdev);
	fail3:
	kfree(dsm_cdev);
	fail2:
	remove_dsmsub_attrs(dsm_class);
	class_destroy(dsm_class);
	fail1:
	unregister_chrdev_region(dsm_devno, 1);
	fail0:
	return result;
	}

	void __exit dsm_exit(void)
	{
	cdev_del(dsm_cdev);
	kfree(dsm_cdev);
	device_destroy(dsm_class, MKDEV(MAJOR(dsm_devno), 0));
	remove_dsmsub_attrs(dsm_class);
	class_destroy(dsm_class);
	unregister_chrdev_region(dsm_devno, 1);
	}

	MODULE_AUTHOR("Tao Guo <tao.guo@amlogic.com>");
	MODULE_DESCRIPTION("Amlogic Descrambler Session Manager Driver");
	MODULE_LICENSE("GPL");

	module_init(dsm_init);
	module_exit(dsm_exit);