qca-nss-drv/nss_mirror_stats.c - manifest_repos/sdk - Git at Google

 /*
  **************************************************************************
  * Copyright (c) 2020-2021, The Linux Foundation. All rights reserved.
  *
  * Permission to use, copy, modify, and/or distribute this software for
  * any purpose with or without fee is hereby granted, provided that the
  * above copyright notice and this permission notice appear in all copies.
  *
  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  **************************************************************************
  */

 #include "nss_stats.h"
 #include "nss_core.h"
 #include "nss_mirror.h"
 #include "nss_mirror_stats.h"
 #include "nss_mirror_strings.h"

 static struct nss_mirror_stats_debug_instance *stats_db[NSS_MAX_MIRROR_DYNAMIC_INTERFACES];
 					/* Mirror stats data structure. */

 /*
  * Atomic notifier data structure for statistics
  */
 ATOMIC_NOTIFIER_HEAD(nss_mirror_stats_notifier);

 static DEFINE_SPINLOCK(nss_mirror_stats_lock);

 /*
  * nss_mirror_stats_get()
  *	Get mirror interface statistics.
  */
 static void nss_mirror_stats_get(void *stats_mem, uint32_t stats_num)
 {
 	struct nss_mirror_stats_debug_instance *stats = (struct nss_mirror_stats_debug_instance *)stats_mem;
 	int i;

 	if (!stats) {
 		nss_warning("No memory to copy mirror interface stats");
 		return;
 	}

 	spin_lock_bh(&nss_mirror_stats_lock);
 	for (i = 0; i < NSS_MAX_MIRROR_DYNAMIC_INTERFACES; i++) {

 		/*
 		 * Copy maximum for given number of instances only.
 		 */
 		if (likely(stats_db[i])) {
 			if (likely(stats_num)) {
 				memcpy(stats, stats_db[i], sizeof(struct nss_mirror_stats_debug_instance));
 				stats++;
 				stats_num--;
 			} else {
 				break;
 			}
 		}
 	}
 	spin_unlock_bh(&nss_mirror_stats_lock);
 }

 /*
  * nss_mirror_stats_read()
  *	Read mirror interface statistics.
  */
 static ssize_t nss_mirror_stats_read(struct file *fp, char __user *ubuf, size_t sz, loff_t *ppos)
 {

 	uint32_t max_output_lines = 2 /* header & footer for instance stats */
 					+ NSS_MAX_MIRROR_DYNAMIC_INTERFACES *
 					 ((NSS_STATS_NODE_MAX + 3 ) + (NSS_MIRROR_STATS_MAX + 3)) /*instance stats */
 					 + 2;
 	size_t size_al = NSS_STATS_MAX_STR_LENGTH * max_output_lines;
 	size_t size_wr = 0;
 	ssize_t bytes_read = 0;
 	struct net_device *dev;
 	struct nss_mirror_stats_debug_instance *mirror_shadow_stats;
 	uint32_t id, mirror_active_instances = atomic_read(&nss_mirror_num_instances);
 	char *lbuf;

 	if (!mirror_active_instances) {
 		return 0;
 	}

 	lbuf = vzalloc(size_al);
 	if (unlikely(!lbuf)) {
 		nss_warning("Could not allocate memory for local statistics buffer");
 		return 0;
 	}

 	mirror_shadow_stats = vzalloc(sizeof(struct nss_mirror_stats_debug_instance) *
 			 mirror_active_instances);
 	if (unlikely(!mirror_shadow_stats)) {
 		nss_warning("Could not allocate memory for base debug statistics buffer");
 		vfree(lbuf);
 		return 0;
 	}

 	/*
 	 * Get all stats
 	 */
 	nss_mirror_stats_get((void *)mirror_shadow_stats, mirror_active_instances);
 	size_wr += nss_stats_banner(lbuf, size_wr, size_al, "mirror stats", NSS_STATS_SINGLE_CORE);

 	/*
 	 * Session stats
 	 */
 	for (id = 0; id < mirror_active_instances; id++) {
 			dev = dev_get_by_index(&init_net, mirror_shadow_stats[id].if_index);
 			if (likely(dev)) {

 				size_wr += scnprintf(lbuf + size_wr, size_al - size_wr, "%d. nss interface id=%d, netdevice=%s\n", id,
 						mirror_shadow_stats[id].if_num, dev->name);
 				dev_put(dev);
 			} else {
 				size_wr += scnprintf(lbuf + size_wr, size_al - size_wr, "%d. nss interface id=%d\n", id,
 						mirror_shadow_stats[id].if_num);
 			}

 			size_wr += nss_stats_fill_common_stats(mirror_shadow_stats[id].if_num, id, lbuf, size_wr, size_al, "mirror");

 			/*
 			 * Mirror interface exception stats.
 			 */
 			size_wr += nss_stats_print("mirror", "mirror exception stats",
 							 id,
 							 nss_mirror_strings_stats,
 							 mirror_shadow_stats[id].stats,
 							 NSS_MIRROR_STATS_MAX,
 							 lbuf, size_wr, size_al);
 	}

 	bytes_read = simple_read_from_buffer(ubuf, sz, ppos, lbuf, size_wr);

 	vfree(mirror_shadow_stats);
 	vfree(lbuf);
 	return bytes_read;
 }

 /*
  * nss_mirror_stats_sync()
  *	API to sync statistics for mirror interface.
  */
 void nss_mirror_stats_sync(struct nss_ctx_instance *nss_ctx,
 		 struct nss_mirror_msg *nmm, uint16_t if_num)
 {
 	uint8_t i, j;
 	struct nss_top_instance *nss_top = nss_ctx->nss_top;
 	struct nss_mirror_stats_sync_msg *stats_msg = &nmm->msg.stats;
 	struct nss_cmn_node_stats *node_stats_ptr = &stats_msg->node_stats;
 	uint32_t *mirror_stats_ptr = (uint32_t *)&stats_msg->mirror_stats;

 	spin_lock_bh(&nss_mirror_stats_lock);
 	for (i = 0; i < NSS_MAX_MIRROR_DYNAMIC_INTERFACES; i++) {
 		if (!stats_db[i] || (stats_db[i]->if_num != if_num)) {
 			continue;
 		}

 		for (j = 0; j < NSS_MIRROR_STATS_MAX; j++) {
 			/*
 			 * Sync stats.
 			 */
 			stats_db[i]->stats[j] += mirror_stats_ptr[j];
 		}
 		spin_unlock_bh(&nss_mirror_stats_lock);
 		goto sync_cmn_stats;
 	}

 	spin_unlock_bh(&nss_mirror_stats_lock);
 	nss_warning("Invalid mirror stats sync message received for %d interface\n", if_num);
 	return;

 sync_cmn_stats:
 	spin_lock_bh(&nss_mirror_stats_lock);

 	/*
 	 * Sync common stats.
 	 */
 	nss_top->stats_node[if_num][NSS_STATS_NODE_RX_PKTS] += node_stats_ptr->rx_packets;
 	nss_top->stats_node[if_num][NSS_STATS_NODE_RX_BYTES] += node_stats_ptr->rx_bytes;
 	nss_top->stats_node[if_num][NSS_STATS_NODE_TX_PKTS] += node_stats_ptr->tx_packets;
 	nss_top->stats_node[if_num][NSS_STATS_NODE_TX_BYTES] += node_stats_ptr->tx_bytes;

 	for (i = 0; i < NSS_MAX_NUM_PRI; i++) {
 		nss_top->stats_node[if_num][NSS_STATS_NODE_RX_QUEUE_0_DROPPED + i] +=
 			node_stats_ptr->rx_dropped[i];
 	}

 	spin_unlock_bh(&nss_mirror_stats_lock);
 }

 /*
  * nss_mirror_stats_reset()
  *	API to reset the mirror interface stats.
  */
 void nss_mirror_stats_reset(uint32_t if_num)
 {
 	struct nss_mirror_stats_debug_instance *mirror_debug_instance = NULL;
 	uint8_t i;

 	/*
 	 * Reset common node stats.
 	 */
 	nss_stats_reset_common_stats(if_num);

 	/*
 	 * Reset mirror stats.
 	 */
 	spin_lock_bh(&nss_mirror_stats_lock);
 	for (i = 0; i < NSS_MAX_MIRROR_DYNAMIC_INTERFACES; i++) {
 		if (!stats_db[i] || (stats_db[i]->if_num != if_num)) {
 			continue;
 		}

 		mirror_debug_instance = stats_db[i];
 		stats_db[i] = NULL;
 		break;
 	}
 	spin_unlock_bh(&nss_mirror_stats_lock);

 	if (mirror_debug_instance) {
 		vfree(mirror_debug_instance);
 	}
 }

 /*
  * nss_mirror_stats_init()
  *	API to initialize mirror debug instance statistics.
  */
 int nss_mirror_stats_init(uint32_t if_num, struct net_device *netdev)
 {
 	struct nss_mirror_stats_debug_instance *mirror_debug_instance = NULL;
 	uint8_t i;

 	mirror_debug_instance =
 		(struct nss_mirror_stats_debug_instance *)vzalloc(sizeof(struct nss_mirror_stats_debug_instance));
 	if (!mirror_debug_instance) {
 		nss_warning("Memory alloc failed for mirror stats instance.\n");
 		return -1;
 	}

 	spin_lock_bh(&nss_mirror_stats_lock);
 	for (i = 0; i < NSS_MAX_MIRROR_DYNAMIC_INTERFACES; i++) {
 		if (stats_db[i] != NULL) {
 			continue;
 		}

 		stats_db[i] = mirror_debug_instance;
 		stats_db[i]->if_num = if_num;
 		stats_db[i]->if_index = netdev->ifindex;
 		spin_unlock_bh(&nss_mirror_stats_lock);
 		return 0;
 	}
 	spin_unlock_bh(&nss_mirror_stats_lock);
 	vfree(mirror_debug_instance);
 	return -1;
 }

 /*
  * nss_mirror_stats_ops
  */
 NSS_STATS_DECLARE_FILE_OPERATIONS(mirror)

 /*
  * nss_mirror_stats_dentry_create()
  *	Create mirror interface statistics debug entry.
  */
 void nss_mirror_stats_dentry_create(void)
 {
 	nss_stats_create_dentry("mirror", &nss_mirror_stats_ops);
 }

 /*
  * nss_mirror_stats_notify()
  *	Sends notifications to all the registered modules.
  *
  * Leverage NSS-FW statistics timing to update Netlink.
  */
 void nss_mirror_stats_notify(struct nss_ctx_instance *nss_ctx, uint32_t if_num)
 {
 	struct nss_mirror_stats_notification mirror_stats;
 	int i;

 	spin_lock_bh(&nss_mirror_stats_lock);
 	for (i = 0; i < NSS_MAX_MIRROR_DYNAMIC_INTERFACES; i++) {
 		if (!stats_db[i] || (stats_db[i]->if_num != if_num)) {
 			continue;
 		}

 		memcpy(mirror_stats.stats_ctx, stats_db[i]->stats, sizeof(mirror_stats.stats_ctx));
 		mirror_stats.core_id = nss_ctx->id;
 		mirror_stats.if_num = if_num;
 		spin_unlock_bh(&nss_mirror_stats_lock);
 		atomic_notifier_call_chain(&nss_mirror_stats_notifier, NSS_STATS_EVENT_NOTIFY, &mirror_stats);
 		return;
 	}
 	spin_unlock_bh(&nss_mirror_stats_lock);
 }

 /*
  * nss_mirror_stats_unregister_notifier()
  *	Deregisters statistics notifier.
  */
 int nss_mirror_stats_unregister_notifier(struct notifier_block *nb)
 {
 	return atomic_notifier_chain_unregister(&nss_mirror_stats_notifier, nb);
 }
 EXPORT_SYMBOL(nss_mirror_stats_unregister_notifier);

 /*
  * nss_mirror_stats_register_notifier()
  *	Registers statistics notifier.
  */
 int nss_mirror_stats_register_notifier(struct notifier_block *nb)
 {
 	return atomic_notifier_chain_register(&nss_mirror_stats_notifier, nb);
 }
 EXPORT_SYMBOL(nss_mirror_stats_register_notifier);
	/*
	**************************************************************************
	* Copyright (c) 2020-2021, The Linux Foundation. All rights reserved.
	*
	* Permission to use, copy, modify, and/or distribute this software for
	* any purpose with or without fee is hereby granted, provided that the
	* above copyright notice and this permission notice appear in all copies.
	*
	* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
	* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
	* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
	* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
	* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
	* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
	**************************************************************************
	*/

	#include "nss_stats.h"
	#include "nss_core.h"
	#include "nss_mirror.h"
	#include "nss_mirror_stats.h"
	#include "nss_mirror_strings.h"

	static struct nss_mirror_stats_debug_instance *stats_db[NSS_MAX_MIRROR_DYNAMIC_INTERFACES];
	/* Mirror stats data structure. */

	/*
	* Atomic notifier data structure for statistics
	*/
	ATOMIC_NOTIFIER_HEAD(nss_mirror_stats_notifier);

	static DEFINE_SPINLOCK(nss_mirror_stats_lock);

	/*
	* nss_mirror_stats_get()
	* Get mirror interface statistics.
	*/
	static void nss_mirror_stats_get(void *stats_mem, uint32_t stats_num)
	{
	struct nss_mirror_stats_debug_instance stats = (struct nss_mirror_stats_debug_instance )stats_mem;
	int i;

	if (!stats) {
	nss_warning("No memory to copy mirror interface stats");
	return;
	}

	spin_lock_bh(&nss_mirror_stats_lock);
	for (i = 0; i < NSS_MAX_MIRROR_DYNAMIC_INTERFACES; i++) {

	/*
	* Copy maximum for given number of instances only.
	*/
	if (likely(stats_db[i])) {
	if (likely(stats_num)) {
	memcpy(stats, stats_db[i], sizeof(struct nss_mirror_stats_debug_instance));
	stats++;
	stats_num--;
	} else {
	break;
	}
	}
	}
	spin_unlock_bh(&nss_mirror_stats_lock);
	}

	/*
	* nss_mirror_stats_read()
	* Read mirror interface statistics.
	*/
	static ssize_t nss_mirror_stats_read(struct file fp, char __user ubuf, size_t sz, loff_t *ppos)
	{

	uint32_t max_output_lines = 2 /* header & footer for instance stats */
	+ NSS_MAX_MIRROR_DYNAMIC_INTERFACES *
	((NSS_STATS_NODE_MAX + 3 ) + (NSS_MIRROR_STATS_MAX + 3)) /instance stats /
	+ 2;
	size_t size_al = NSS_STATS_MAX_STR_LENGTH * max_output_lines;
	size_t size_wr = 0;
	ssize_t bytes_read = 0;
	struct net_device *dev;
	struct nss_mirror_stats_debug_instance *mirror_shadow_stats;
	uint32_t id, mirror_active_instances = atomic_read(&nss_mirror_num_instances);
	char *lbuf;

	if (!mirror_active_instances) {
	return 0;
	}

	lbuf = vzalloc(size_al);
	if (unlikely(!lbuf)) {
	nss_warning("Could not allocate memory for local statistics buffer");
	return 0;
	}

	mirror_shadow_stats = vzalloc(sizeof(struct nss_mirror_stats_debug_instance) *
	mirror_active_instances);
	if (unlikely(!mirror_shadow_stats)) {
	nss_warning("Could not allocate memory for base debug statistics buffer");
	vfree(lbuf);
	return 0;
	}

	/*
	* Get all stats
	*/
	nss_mirror_stats_get((void *)mirror_shadow_stats, mirror_active_instances);
	size_wr += nss_stats_banner(lbuf, size_wr, size_al, "mirror stats", NSS_STATS_SINGLE_CORE);

	/*
	* Session stats
	*/
	for (id = 0; id < mirror_active_instances; id++) {
	dev = dev_get_by_index(&init_net, mirror_shadow_stats[id].if_index);
	if (likely(dev)) {

	size_wr += scnprintf(lbuf + size_wr, size_al - size_wr, "%d. nss interface id=%d, netdevice=%s\n", id,
	mirror_shadow_stats[id].if_num, dev->name);
	dev_put(dev);
	} else {
	size_wr += scnprintf(lbuf + size_wr, size_al - size_wr, "%d. nss interface id=%d\n", id,
	mirror_shadow_stats[id].if_num);
	}

	size_wr += nss_stats_fill_common_stats(mirror_shadow_stats[id].if_num, id, lbuf, size_wr, size_al, "mirror");

	/*
	* Mirror interface exception stats.
	*/
	size_wr += nss_stats_print("mirror", "mirror exception stats",
	id,
	nss_mirror_strings_stats,
	mirror_shadow_stats[id].stats,
	NSS_MIRROR_STATS_MAX,
	lbuf, size_wr, size_al);
	}

	bytes_read = simple_read_from_buffer(ubuf, sz, ppos, lbuf, size_wr);

	vfree(mirror_shadow_stats);
	vfree(lbuf);
	return bytes_read;
	}

	/*
	* nss_mirror_stats_sync()
	* API to sync statistics for mirror interface.
	*/
	void nss_mirror_stats_sync(struct nss_ctx_instance *nss_ctx,
	struct nss_mirror_msg *nmm, uint16_t if_num)
	{
	uint8_t i, j;
	struct nss_top_instance *nss_top = nss_ctx->nss_top;
	struct nss_mirror_stats_sync_msg *stats_msg = &nmm->msg.stats;
	struct nss_cmn_node_stats *node_stats_ptr = &stats_msg->node_stats;
	uint32_t mirror_stats_ptr = (uint32_t )&stats_msg->mirror_stats;

	spin_lock_bh(&nss_mirror_stats_lock);
	for (i = 0; i < NSS_MAX_MIRROR_DYNAMIC_INTERFACES; i++) {
	if (!stats_db[i] \|\| (stats_db[i]->if_num != if_num)) {
	continue;
	}

	for (j = 0; j < NSS_MIRROR_STATS_MAX; j++) {
	/*
	* Sync stats.
	*/
	stats_db[i]->stats[j] += mirror_stats_ptr[j];
	}
	spin_unlock_bh(&nss_mirror_stats_lock);
	goto sync_cmn_stats;
	}

	spin_unlock_bh(&nss_mirror_stats_lock);
	nss_warning("Invalid mirror stats sync message received for %d interface\n", if_num);
	return;

	sync_cmn_stats:
	spin_lock_bh(&nss_mirror_stats_lock);

	/*
	* Sync common stats.
	*/
	nss_top->stats_node[if_num][NSS_STATS_NODE_RX_PKTS] += node_stats_ptr->rx_packets;
	nss_top->stats_node[if_num][NSS_STATS_NODE_RX_BYTES] += node_stats_ptr->rx_bytes;
	nss_top->stats_node[if_num][NSS_STATS_NODE_TX_PKTS] += node_stats_ptr->tx_packets;
	nss_top->stats_node[if_num][NSS_STATS_NODE_TX_BYTES] += node_stats_ptr->tx_bytes;

	for (i = 0; i < NSS_MAX_NUM_PRI; i++) {
	nss_top->stats_node[if_num][NSS_STATS_NODE_RX_QUEUE_0_DROPPED + i] +=
	node_stats_ptr->rx_dropped[i];
	}

	spin_unlock_bh(&nss_mirror_stats_lock);
	}

	/*
	* nss_mirror_stats_reset()
	* API to reset the mirror interface stats.
	*/
	void nss_mirror_stats_reset(uint32_t if_num)
	{
	struct nss_mirror_stats_debug_instance *mirror_debug_instance = NULL;
	uint8_t i;

	/*
	* Reset common node stats.
	*/
	nss_stats_reset_common_stats(if_num);

	/*
	* Reset mirror stats.
	*/
	spin_lock_bh(&nss_mirror_stats_lock);
	for (i = 0; i < NSS_MAX_MIRROR_DYNAMIC_INTERFACES; i++) {
	if (!stats_db[i] \|\| (stats_db[i]->if_num != if_num)) {
	continue;
	}

	mirror_debug_instance = stats_db[i];
	stats_db[i] = NULL;
	break;
	}
	spin_unlock_bh(&nss_mirror_stats_lock);

	if (mirror_debug_instance) {
	vfree(mirror_debug_instance);
	}
	}

	/*
	* nss_mirror_stats_init()
	* API to initialize mirror debug instance statistics.
	*/
	int nss_mirror_stats_init(uint32_t if_num, struct net_device *netdev)
	{
	struct nss_mirror_stats_debug_instance *mirror_debug_instance = NULL;
	uint8_t i;

	mirror_debug_instance =
	(struct nss_mirror_stats_debug_instance *)vzalloc(sizeof(struct nss_mirror_stats_debug_instance));
	if (!mirror_debug_instance) {
	nss_warning("Memory alloc failed for mirror stats instance.\n");
	return -1;
	}

	spin_lock_bh(&nss_mirror_stats_lock);
	for (i = 0; i < NSS_MAX_MIRROR_DYNAMIC_INTERFACES; i++) {
	if (stats_db[i] != NULL) {
	continue;
	}

	stats_db[i] = mirror_debug_instance;
	stats_db[i]->if_num = if_num;
	stats_db[i]->if_index = netdev->ifindex;
	spin_unlock_bh(&nss_mirror_stats_lock);
	return 0;
	}
	spin_unlock_bh(&nss_mirror_stats_lock);
	vfree(mirror_debug_instance);
	return -1;
	}

	/*
	* nss_mirror_stats_ops
	*/
	NSS_STATS_DECLARE_FILE_OPERATIONS(mirror)

	/*
	* nss_mirror_stats_dentry_create()
	* Create mirror interface statistics debug entry.
	*/
	void nss_mirror_stats_dentry_create(void)
	{
	nss_stats_create_dentry("mirror", &nss_mirror_stats_ops);
	}

	/*
	* nss_mirror_stats_notify()
	* Sends notifications to all the registered modules.
	*
	* Leverage NSS-FW statistics timing to update Netlink.
	*/
	void nss_mirror_stats_notify(struct nss_ctx_instance *nss_ctx, uint32_t if_num)
	{
	struct nss_mirror_stats_notification mirror_stats;
	int i;

	spin_lock_bh(&nss_mirror_stats_lock);
	for (i = 0; i < NSS_MAX_MIRROR_DYNAMIC_INTERFACES; i++) {
	if (!stats_db[i] \|\| (stats_db[i]->if_num != if_num)) {
	continue;
	}

	memcpy(mirror_stats.stats_ctx, stats_db[i]->stats, sizeof(mirror_stats.stats_ctx));
	mirror_stats.core_id = nss_ctx->id;
	mirror_stats.if_num = if_num;
	spin_unlock_bh(&nss_mirror_stats_lock);
	atomic_notifier_call_chain(&nss_mirror_stats_notifier, NSS_STATS_EVENT_NOTIFY, &mirror_stats);
	return;
	}
	spin_unlock_bh(&nss_mirror_stats_lock);
	}

	/*
	* nss_mirror_stats_unregister_notifier()
	* Deregisters statistics notifier.
	*/
	int nss_mirror_stats_unregister_notifier(struct notifier_block *nb)
	{
	return atomic_notifier_chain_unregister(&nss_mirror_stats_notifier, nb);
	}
	EXPORT_SYMBOL(nss_mirror_stats_unregister_notifier);

	/*
	* nss_mirror_stats_register_notifier()
	* Registers statistics notifier.
	*/
	int nss_mirror_stats_register_notifier(struct notifier_block *nb)
	{
	return atomic_notifier_chain_register(&nss_mirror_stats_notifier, nb);
	}
	EXPORT_SYMBOL(nss_mirror_stats_register_notifier);