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

 /*
  **************************************************************************
  * Copyright (c) 2016-2021, 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_tx_rx_common.h"
 #include "nss_gre_tunnel_stats.h"
 #include "nss_gre_tunnel_log.h"
 #include "nss_gre_tunnel_strings.h"

 #define NSS_GRE_TUNNEL_TX_TIMEOUT 3000 /* 3 Seconds */

 /*
  * Private data structure
  */
 static struct nss_gre_tunnel_pvt {
 	struct semaphore sem;
 	struct completion complete;
 	int response;
 	void *cb;
 	void *app_data;
 } gre_tunnel_pvt;

 /*
  * nss_gre_tunnel_verify_if_num()
  *	Verify if_num passed to us.
  */
 static bool nss_gre_tunnel_verify_if_num(uint32_t if_num)
 {
 	uint32_t type = nss_dynamic_interface_get_type(nss_gre_tunnel_get_ctx(), if_num);

 	switch (type) {
 	case NSS_DYNAMIC_INTERFACE_TYPE_GRE_TUNNEL_INNER:
 	case NSS_DYNAMIC_INTERFACE_TYPE_GRE_TUNNEL_INLINE_INNER:
 	case NSS_DYNAMIC_INTERFACE_TYPE_GRE_TUNNEL_OUTER:
 	case NSS_DYNAMIC_INTERFACE_TYPE_GRE_TUNNEL_INLINE_OUTER:
 	case NSS_DYNAMIC_INTERFACE_TYPE_GRE_TUNNEL_INNER_EXCEPTION:
 		return true;
 	default:
 		return false;
 	}
 }

 /*
  * nss_gre_tunnel_handler()
  *	Handle NSS to HLOS messages for gre_tunnel
  */
 static void nss_gre_tunnel_handler(struct nss_ctx_instance *nss_ctx, struct nss_cmn_msg *ncm, __attribute__((unused))void *app_data)
 {
 	struct nss_gre_tunnel_msg *ngtm = (struct nss_gre_tunnel_msg *)ncm;
 	void *ctx;

 	nss_gre_tunnel_msg_callback_t cb;

 	NSS_VERIFY_CTX_MAGIC(nss_ctx);
 	BUG_ON(!nss_gre_tunnel_verify_if_num(ncm->interface));

 	/*
 	 * Trace Messages
 	 */
 	nss_gre_tunnel_log_rx_msg(ngtm);

 	/*
 	 * Is this a valid request/response packet?
 	 */
 	if (ncm->type >= NSS_GRE_TUNNEL_MSG_MAX) {
 		nss_warning("%px: received invalid message %d for GRE_TUNNEL interface %d", nss_ctx, ncm->type, ncm->interface);
 		return;
 	}

 	if (nss_cmn_get_msg_len(ncm) > sizeof(struct nss_gre_tunnel_msg)) {
 		nss_warning("%px: gre_tunnel message length is invalid: %d", nss_ctx, ncm->len);
 		return;
 	}

 	/*
 	 * Check messages
 	 */
 	switch (ngtm->cm.type) {
 	case NSS_GRE_TUNNEL_MSG_STATS:
 		nss_gre_tunnel_stats_session_sync(nss_ctx, &ngtm->msg.stats, ncm->interface);
 		nss_gre_tunnel_stats_notify(nss_ctx, ncm->interface);
 		break;
 	}

 	/*
 	 * Update the callback and app_data for NOTIFY messages
 	 */
 	if (ncm->response == NSS_CMN_RESPONSE_NOTIFY) {
 		ncm->cb = (nss_ptr_t)nss_ctx->nss_top->gre_tunnel_msg_callback;
 		ncm->app_data = (nss_ptr_t)nss_ctx->subsys_dp_register[ncm->interface].app_data;
 	}

 	nss_core_log_msg_failures(nss_ctx, ncm);

 	/*
 	 * callback
 	 */
 	cb = (nss_gre_tunnel_msg_callback_t)ncm->cb;
 	ctx = (void *)ncm->app_data;

 	/*
 	 * call GRE Tunnel session callback
 	 */
 	if (!cb) {
 		return;
 	}

 	cb(ctx, ngtm);
 }

 /*
  * nss_gre_tunnel_inquiry()
  *	Inquiry if a GRE tunnel has been established in NSS FW.
  *
  * Input parameters:
  *	inquiry_info->ip_type
  *	inquiry_info->src_ip
  *	inquiry_info->dest_ip
  *	inquiry_info->gre_mode
  *	 if (gre_mode == NSS_GRE_TUNNEL_MODE_GRE_UDP)
  *		inquiry_info->src_port
  *		inquiry_info->dest_port
  *	inquiry_info->encrypt_type	-- currently not checked in FW,
  */
 nss_tx_status_t nss_gre_tunnel_inquiry(
 		struct nss_gre_tunnel_configure *inquiry_info,
 		nss_gre_tunnel_msg_callback_t cb, void *app_data)
 {
 	nss_tx_status_t nss_tx_status;
 	struct nss_gre_tunnel_msg nim;
 	struct nss_ctx_instance *nss_ctx = nss_gre_tunnel_get_ctx();

 	/*
 	 * Initialize inquiry message structure.
 	 * This is async message and the result will be returned
 	 * to the caller by the msg_callback passed in.
 	 */
 	memset(&nim, 0, sizeof(nim));
 	nss_gre_tunnel_msg_init(&nim, NSS_GRE_TUNNEL_INTERFACE,
 			NSS_GRE_TUNNEL_MSG_INQUIRY,
 			sizeof(struct nss_gre_tunnel_configure),
 			cb, app_data);
 	nim.msg.configure = *inquiry_info;
 	nss_tx_status = nss_gre_tunnel_tx_msg(nss_ctx, &nim);
 	if (nss_tx_status != NSS_TX_SUCCESS) {
 		nss_warning("%px: Send GT inquiry message failed\n", inquiry_info);
 	}

 	return nss_tx_status;
 }
 EXPORT_SYMBOL(nss_gre_tunnel_inquiry);

 /*
  * nss_get_gre_tunnel_context()
  *	Return the core ctx which the feature is on
  */
 struct nss_ctx_instance *nss_gre_tunnel_get_ctx(void)
 {
 	return (struct nss_ctx_instance *)&nss_top_main.nss[nss_top_main.gre_tunnel_handler_id];
 }
 EXPORT_SYMBOL(nss_gre_tunnel_get_ctx);

 /*
  * nss_gre_tunnel_ifnum_with_core_id()
  *	Append core id to GRE tunnel interface num
  */
 int nss_gre_tunnel_ifnum_with_core_id(int if_num)
 {
 	struct nss_ctx_instance *nss_ctx = nss_gre_tunnel_get_ctx();
 	BUG_ON(!nss_gre_tunnel_verify_if_num(if_num));
 	NSS_VERIFY_CTX_MAGIC(nss_ctx);

 	if (nss_is_dynamic_interface(if_num) == false) {
 		nss_info("%px: Invalid if_num: %d, must be a dynamic interface\n", nss_ctx, if_num);
 		return 0;
 	}

 	return NSS_INTERFACE_NUM_APPEND_COREID(nss_ctx, if_num);
 }
 EXPORT_SYMBOL(nss_gre_tunnel_ifnum_with_core_id);

 /*
  * nss_gre_tunnel_tx_buf()
  *	Transmit buffer over GRE Tunnel interface
  */
 nss_tx_status_t nss_gre_tunnel_tx_buf(struct sk_buff *skb, uint32_t if_num,
 				struct nss_ctx_instance *nss_ctx)
 {
 	BUG_ON(!nss_gre_tunnel_verify_if_num(if_num));

 	return nss_core_send_packet(nss_ctx, skb, if_num, H2N_BIT_FLAG_VIRTUAL_BUFFER | H2N_BIT_FLAG_BUFFER_REUSABLE);
 }
 EXPORT_SYMBOL(nss_gre_tunnel_tx_buf);

 /*
  * nss_gre_tunnel_tx_msg()
  *	Transmit a gre_tunnel message to NSS firmware
  */
 nss_tx_status_t nss_gre_tunnel_tx_msg(struct nss_ctx_instance *nss_ctx, struct nss_gre_tunnel_msg *msg)
 {
 	struct nss_cmn_msg *ncm = &msg->cm;

 	/*
 	 * Trace Messages
 	 */
 	nss_gre_tunnel_log_tx_msg(msg);

 	/*
 	 * Sanity check message
 	 */
 	if (ncm->type >= NSS_GRE_TUNNEL_MSG_MAX) {
 		nss_warning("%px: gre_tunnel message type out of range: %d",
 			nss_ctx, ncm->type);
 		return NSS_TX_FAILURE;
 	}

 	BUG_ON(!nss_gre_tunnel_verify_if_num(ncm->interface));

 	return nss_core_send_cmd(nss_ctx, msg, sizeof(*msg), NSS_NBUF_PAYLOAD_SIZE);
 }
 EXPORT_SYMBOL(nss_gre_tunnel_tx_msg);

 /*
  * nss_gre_tunnel_callback()
  *	Callback to handle the completion of NSS->HLOS messages.
  */
 static void nss_gre_tunnel_callback(void *app_data, struct nss_gre_tunnel_msg *ngtm)
 {
 	nss_gre_tunnel_msg_callback_t callback = (nss_gre_tunnel_msg_callback_t)gre_tunnel_pvt.cb;
 	void *data = gre_tunnel_pvt.app_data;

 	gre_tunnel_pvt.response = NSS_TX_SUCCESS;
 	gre_tunnel_pvt.cb = NULL;
 	gre_tunnel_pvt.app_data = NULL;

 	if (ngtm->cm.response != NSS_CMN_RESPONSE_ACK) {
 		nss_warning("gre tunnel Error response %d\n", ngtm->cm.response);
 		gre_tunnel_pvt.response = ngtm->cm.response;
 	}

 	if (callback) {
 		callback(data, ngtm);
 	}
 	complete(&gre_tunnel_pvt.complete);
 }

 /*
  * nss_gre_tunnel_tx_msg()
  *	Transmit a GRE Tunnel message to NSS firmware synchronously.
  */
 nss_tx_status_t nss_gre_tunnel_tx_msg_sync(struct nss_ctx_instance *nss_ctx, struct nss_gre_tunnel_msg *ngtm)
 {
 	nss_tx_status_t status;
 	int ret = 0;

 	down(&gre_tunnel_pvt.sem);
 	gre_tunnel_pvt.cb = (void *)ngtm->cm.cb;
 	gre_tunnel_pvt.app_data = (void *)ngtm->cm.app_data;

 	ngtm->cm.cb = (nss_ptr_t)nss_gre_tunnel_callback;
 	ngtm->cm.app_data = (nss_ptr_t)NULL;

 	status = nss_gre_tunnel_tx_msg(nss_ctx, ngtm);
 	if (status != NSS_TX_SUCCESS) {
 		nss_warning("%px: gre_tunnel_tx_msg failed\n", nss_ctx);
 		up(&gre_tunnel_pvt.sem);
 		return status;
 	}

 	ret = wait_for_completion_timeout(&gre_tunnel_pvt.complete, msecs_to_jiffies(NSS_GRE_TUNNEL_TX_TIMEOUT));

 	if (!ret) {
 		nss_warning("%px: GRE Tunnel msg tx failed due to timeout\n", nss_ctx);
 		gre_tunnel_pvt.response = NSS_TX_FAILURE;
 	}

 	status = gre_tunnel_pvt.response;
 	up(&gre_tunnel_pvt.sem);
 	return status;
 }
 EXPORT_SYMBOL(nss_gre_tunnel_tx_msg_sync);

 /*
  * nss_gre_tunnel_msg_init()
  *	Initialize gre_tunnel msg.
  */
 void nss_gre_tunnel_msg_init(struct nss_gre_tunnel_msg *ngtm, uint16_t if_num,
 			uint32_t type, uint32_t len, void *cb, void *app_data)
 {
 	nss_cmn_msg_init(&ngtm->cm, if_num, type, len, cb, app_data);
 }
 EXPORT_SYMBOL(nss_gre_tunnel_msg_init);

 /*
  * nss_gre_tunnel_register_if()
  *	Register netdev
  */
 struct nss_ctx_instance *nss_gre_tunnel_register_if(uint32_t if_num,
 					      nss_gre_tunnel_data_callback_t cb,
 					      nss_gre_tunnel_msg_callback_t ev_cb,
 					      struct net_device *netdev,
 					      uint32_t features,
 					      void *app_ctx)
 {
 	int32_t i;

 	struct nss_ctx_instance *nss_ctx = nss_gre_tunnel_get_ctx();

 	BUG_ON(!nss_gre_tunnel_verify_if_num(if_num));

 	spin_lock_bh(&nss_gre_tunnel_stats_lock);
 	for (i = 0; i < NSS_MAX_GRE_TUNNEL_SESSIONS; i++) {
 		if (!session_stats[i].valid) {
 			session_stats[i].valid = true;
 			session_stats[i].if_num = if_num;
 			session_stats[i].if_index = netdev->ifindex;
 			break;
 		}
 	}
 	spin_unlock_bh(&nss_gre_tunnel_stats_lock);

 	if (i == NSS_MAX_GRE_TUNNEL_SESSIONS) {
 		nss_warning("%px: Cannot find free slot for GRE Tunnel session stats, I/F:%u\n", nss_ctx, if_num);
 		return NULL;
 	}

 	if (nss_ctx->subsys_dp_register[if_num].ndev) {
 		nss_warning("%px: Cannot find free slot for GRE Tunnel NSS I/F:%u\n", nss_ctx, if_num);
 		session_stats[i].valid = false;
 		session_stats[i].if_num = 0;
 		session_stats[i].if_index = 0;
 		return NULL;
 	}

 	nss_core_register_subsys_dp(nss_ctx, if_num, cb, NULL, app_ctx, netdev, features);

 	nss_top_main.gre_tunnel_msg_callback = ev_cb;
 	nss_core_register_handler(nss_ctx, if_num, nss_gre_tunnel_handler, app_ctx);
 	nss_gre_tunnel_stats_dentry_create();
 	nss_gre_tunnel_strings_dentry_create();

 	return nss_ctx;
 }
 EXPORT_SYMBOL(nss_gre_tunnel_register_if);

 /*
  * nss_gre_tunnel_unregister_if()
  *	Unregister netdev
  */
 void nss_gre_tunnel_unregister_if(uint32_t if_num)
 {
 	int32_t i;
 	struct nss_ctx_instance *nss_ctx = nss_gre_tunnel_get_ctx();

 	BUG_ON(!nss_gre_tunnel_verify_if_num(if_num));

 	spin_lock_bh(&nss_gre_tunnel_stats_lock);
 	for (i = 0; i < NSS_MAX_GRE_TUNNEL_SESSIONS; i++) {
 		if (session_stats[i].if_num == if_num) {
 			memset(&session_stats[i], 0,
 				sizeof(struct nss_gre_tunnel_stats_session));
 			break;
 		}
 	}
 	spin_unlock_bh(&nss_gre_tunnel_stats_lock);

 	if (i == NSS_MAX_GRE_TUNNEL_SESSIONS) {
 		nss_warning("%px: Cannot find debug stats for GRE Tunnel session: %d\n", nss_ctx, if_num);
 		return;
 	}

 	if (!nss_ctx->subsys_dp_register[if_num].ndev) {
 		nss_warning("%px: Cannot find registered netdev for GRE Tunnel NSS I/F: %d\n", nss_ctx, if_num);

 		return;
 	}

 	nss_core_unregister_subsys_dp(nss_ctx, if_num);

 	nss_top_main.gre_tunnel_msg_callback = NULL;
 	nss_core_unregister_handler(nss_ctx, if_num);
 }
 EXPORT_SYMBOL(nss_gre_tunnel_unregister_if);
	/*
	**************************************************************************
	* Copyright (c) 2016-2021, 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_tx_rx_common.h"
	#include "nss_gre_tunnel_stats.h"
	#include "nss_gre_tunnel_log.h"
	#include "nss_gre_tunnel_strings.h"

	#define NSS_GRE_TUNNEL_TX_TIMEOUT 3000 /* 3 Seconds */

	/*
	* Private data structure
	*/
	static struct nss_gre_tunnel_pvt {
	struct semaphore sem;
	struct completion complete;
	int response;
	void *cb;
	void *app_data;
	} gre_tunnel_pvt;

	/*
	* nss_gre_tunnel_verify_if_num()
	* Verify if_num passed to us.
	*/
	static bool nss_gre_tunnel_verify_if_num(uint32_t if_num)
	{
	uint32_t type = nss_dynamic_interface_get_type(nss_gre_tunnel_get_ctx(), if_num);

	switch (type) {
	case NSS_DYNAMIC_INTERFACE_TYPE_GRE_TUNNEL_INNER:
	case NSS_DYNAMIC_INTERFACE_TYPE_GRE_TUNNEL_INLINE_INNER:
	case NSS_DYNAMIC_INTERFACE_TYPE_GRE_TUNNEL_OUTER:
	case NSS_DYNAMIC_INTERFACE_TYPE_GRE_TUNNEL_INLINE_OUTER:
	case NSS_DYNAMIC_INTERFACE_TYPE_GRE_TUNNEL_INNER_EXCEPTION:
	return true;
	default:
	return false;
	}
	}

	/*
	* nss_gre_tunnel_handler()
	* Handle NSS to HLOS messages for gre_tunnel
	*/
	static void nss_gre_tunnel_handler(struct nss_ctx_instance nss_ctx, struct nss_cmn_msg ncm, __attribute__((unused))void *app_data)
	{
	struct nss_gre_tunnel_msg ngtm = (struct nss_gre_tunnel_msg )ncm;
	void *ctx;

	nss_gre_tunnel_msg_callback_t cb;

	NSS_VERIFY_CTX_MAGIC(nss_ctx);
	BUG_ON(!nss_gre_tunnel_verify_if_num(ncm->interface));

	/*
	* Trace Messages
	*/
	nss_gre_tunnel_log_rx_msg(ngtm);

	/*
	* Is this a valid request/response packet?
	*/
	if (ncm->type >= NSS_GRE_TUNNEL_MSG_MAX) {
	nss_warning("%px: received invalid message %d for GRE_TUNNEL interface %d", nss_ctx, ncm->type, ncm->interface);
	return;
	}

	if (nss_cmn_get_msg_len(ncm) > sizeof(struct nss_gre_tunnel_msg)) {
	nss_warning("%px: gre_tunnel message length is invalid: %d", nss_ctx, ncm->len);
	return;
	}

	/*
	* Check messages
	*/
	switch (ngtm->cm.type) {
	case NSS_GRE_TUNNEL_MSG_STATS:
	nss_gre_tunnel_stats_session_sync(nss_ctx, &ngtm->msg.stats, ncm->interface);
	nss_gre_tunnel_stats_notify(nss_ctx, ncm->interface);
	break;
	}

	/*
	* Update the callback and app_data for NOTIFY messages
	*/
	if (ncm->response == NSS_CMN_RESPONSE_NOTIFY) {
	ncm->cb = (nss_ptr_t)nss_ctx->nss_top->gre_tunnel_msg_callback;
	ncm->app_data = (nss_ptr_t)nss_ctx->subsys_dp_register[ncm->interface].app_data;
	}

	nss_core_log_msg_failures(nss_ctx, ncm);

	/*
	* callback
	*/
	cb = (nss_gre_tunnel_msg_callback_t)ncm->cb;
	ctx = (void *)ncm->app_data;

	/*
	* call GRE Tunnel session callback
	*/
	if (!cb) {
	return;
	}

	cb(ctx, ngtm);
	}

	/*
	* nss_gre_tunnel_inquiry()
	* Inquiry if a GRE tunnel has been established in NSS FW.
	*
	* Input parameters:
	* inquiry_info->ip_type
	* inquiry_info->src_ip
	* inquiry_info->dest_ip
	* inquiry_info->gre_mode
	* if (gre_mode == NSS_GRE_TUNNEL_MODE_GRE_UDP)
	* inquiry_info->src_port
	* inquiry_info->dest_port
	* inquiry_info->encrypt_type -- currently not checked in FW,
	*/
	nss_tx_status_t nss_gre_tunnel_inquiry(
	struct nss_gre_tunnel_configure *inquiry_info,
	nss_gre_tunnel_msg_callback_t cb, void *app_data)
	{
	nss_tx_status_t nss_tx_status;
	struct nss_gre_tunnel_msg nim;
	struct nss_ctx_instance *nss_ctx = nss_gre_tunnel_get_ctx();

	/*
	* Initialize inquiry message structure.
	* This is async message and the result will be returned
	* to the caller by the msg_callback passed in.
	*/
	memset(&nim, 0, sizeof(nim));
	nss_gre_tunnel_msg_init(&nim, NSS_GRE_TUNNEL_INTERFACE,
	NSS_GRE_TUNNEL_MSG_INQUIRY,
	sizeof(struct nss_gre_tunnel_configure),
	cb, app_data);
	nim.msg.configure = *inquiry_info;
	nss_tx_status = nss_gre_tunnel_tx_msg(nss_ctx, &nim);
	if (nss_tx_status != NSS_TX_SUCCESS) {
	nss_warning("%px: Send GT inquiry message failed\n", inquiry_info);
	}

	return nss_tx_status;
	}
	EXPORT_SYMBOL(nss_gre_tunnel_inquiry);

	/*
	* nss_get_gre_tunnel_context()
	* Return the core ctx which the feature is on
	*/
	struct nss_ctx_instance *nss_gre_tunnel_get_ctx(void)
	{
	return (struct nss_ctx_instance *)&nss_top_main.nss[nss_top_main.gre_tunnel_handler_id];
	}
	EXPORT_SYMBOL(nss_gre_tunnel_get_ctx);

	/*
	* nss_gre_tunnel_ifnum_with_core_id()
	* Append core id to GRE tunnel interface num
	*/
	int nss_gre_tunnel_ifnum_with_core_id(int if_num)
	{
	struct nss_ctx_instance *nss_ctx = nss_gre_tunnel_get_ctx();
	BUG_ON(!nss_gre_tunnel_verify_if_num(if_num));
	NSS_VERIFY_CTX_MAGIC(nss_ctx);

	if (nss_is_dynamic_interface(if_num) == false) {
	nss_info("%px: Invalid if_num: %d, must be a dynamic interface\n", nss_ctx, if_num);
	return 0;
	}

	return NSS_INTERFACE_NUM_APPEND_COREID(nss_ctx, if_num);
	}
	EXPORT_SYMBOL(nss_gre_tunnel_ifnum_with_core_id);

	/*
	* nss_gre_tunnel_tx_buf()
	* Transmit buffer over GRE Tunnel interface
	*/
	nss_tx_status_t nss_gre_tunnel_tx_buf(struct sk_buff *skb, uint32_t if_num,
	struct nss_ctx_instance *nss_ctx)
	{
	BUG_ON(!nss_gre_tunnel_verify_if_num(if_num));

	return nss_core_send_packet(nss_ctx, skb, if_num, H2N_BIT_FLAG_VIRTUAL_BUFFER \| H2N_BIT_FLAG_BUFFER_REUSABLE);
	}
	EXPORT_SYMBOL(nss_gre_tunnel_tx_buf);

	/*
	* nss_gre_tunnel_tx_msg()
	* Transmit a gre_tunnel message to NSS firmware
	*/
	nss_tx_status_t nss_gre_tunnel_tx_msg(struct nss_ctx_instance nss_ctx, struct nss_gre_tunnel_msg msg)
	{
	struct nss_cmn_msg *ncm = &msg->cm;

	/*
	* Trace Messages
	*/
	nss_gre_tunnel_log_tx_msg(msg);

	/*
	* Sanity check message
	*/
	if (ncm->type >= NSS_GRE_TUNNEL_MSG_MAX) {
	nss_warning("%px: gre_tunnel message type out of range: %d",
	nss_ctx, ncm->type);
	return NSS_TX_FAILURE;
	}

	BUG_ON(!nss_gre_tunnel_verify_if_num(ncm->interface));

	return nss_core_send_cmd(nss_ctx, msg, sizeof(*msg), NSS_NBUF_PAYLOAD_SIZE);
	}
	EXPORT_SYMBOL(nss_gre_tunnel_tx_msg);

	/*
	* nss_gre_tunnel_callback()
	* Callback to handle the completion of NSS->HLOS messages.
	*/
	static void nss_gre_tunnel_callback(void app_data, struct nss_gre_tunnel_msg ngtm)
	{
	nss_gre_tunnel_msg_callback_t callback = (nss_gre_tunnel_msg_callback_t)gre_tunnel_pvt.cb;
	void *data = gre_tunnel_pvt.app_data;

	gre_tunnel_pvt.response = NSS_TX_SUCCESS;
	gre_tunnel_pvt.cb = NULL;
	gre_tunnel_pvt.app_data = NULL;

	if (ngtm->cm.response != NSS_CMN_RESPONSE_ACK) {
	nss_warning("gre tunnel Error response %d\n", ngtm->cm.response);
	gre_tunnel_pvt.response = ngtm->cm.response;
	}

	if (callback) {
	callback(data, ngtm);
	}
	complete(&gre_tunnel_pvt.complete);
	}

	/*
	* nss_gre_tunnel_tx_msg()
	* Transmit a GRE Tunnel message to NSS firmware synchronously.
	*/
	nss_tx_status_t nss_gre_tunnel_tx_msg_sync(struct nss_ctx_instance nss_ctx, struct nss_gre_tunnel_msg ngtm)
	{
	nss_tx_status_t status;
	int ret = 0;

	down(&gre_tunnel_pvt.sem);
	gre_tunnel_pvt.cb = (void *)ngtm->cm.cb;
	gre_tunnel_pvt.app_data = (void *)ngtm->cm.app_data;

	ngtm->cm.cb = (nss_ptr_t)nss_gre_tunnel_callback;
	ngtm->cm.app_data = (nss_ptr_t)NULL;

	status = nss_gre_tunnel_tx_msg(nss_ctx, ngtm);
	if (status != NSS_TX_SUCCESS) {
	nss_warning("%px: gre_tunnel_tx_msg failed\n", nss_ctx);
	up(&gre_tunnel_pvt.sem);
	return status;
	}

	ret = wait_for_completion_timeout(&gre_tunnel_pvt.complete, msecs_to_jiffies(NSS_GRE_TUNNEL_TX_TIMEOUT));

	if (!ret) {
	nss_warning("%px: GRE Tunnel msg tx failed due to timeout\n", nss_ctx);
	gre_tunnel_pvt.response = NSS_TX_FAILURE;
	}

	status = gre_tunnel_pvt.response;
	up(&gre_tunnel_pvt.sem);
	return status;
	}
	EXPORT_SYMBOL(nss_gre_tunnel_tx_msg_sync);

	/*
	* nss_gre_tunnel_msg_init()
	* Initialize gre_tunnel msg.
	*/
	void nss_gre_tunnel_msg_init(struct nss_gre_tunnel_msg *ngtm, uint16_t if_num,
	uint32_t type, uint32_t len, void cb, void app_data)
	{
	nss_cmn_msg_init(&ngtm->cm, if_num, type, len, cb, app_data);
	}
	EXPORT_SYMBOL(nss_gre_tunnel_msg_init);

	/*
	* nss_gre_tunnel_register_if()
	* Register netdev
	*/
	struct nss_ctx_instance *nss_gre_tunnel_register_if(uint32_t if_num,
	nss_gre_tunnel_data_callback_t cb,
	nss_gre_tunnel_msg_callback_t ev_cb,
	struct net_device *netdev,
	uint32_t features,
	void *app_ctx)
	{
	int32_t i;

	struct nss_ctx_instance *nss_ctx = nss_gre_tunnel_get_ctx();

	BUG_ON(!nss_gre_tunnel_verify_if_num(if_num));

	spin_lock_bh(&nss_gre_tunnel_stats_lock);
	for (i = 0; i < NSS_MAX_GRE_TUNNEL_SESSIONS; i++) {
	if (!session_stats[i].valid) {
	session_stats[i].valid = true;
	session_stats[i].if_num = if_num;
	session_stats[i].if_index = netdev->ifindex;
	break;
	}
	}
	spin_unlock_bh(&nss_gre_tunnel_stats_lock);

	if (i == NSS_MAX_GRE_TUNNEL_SESSIONS) {
	nss_warning("%px: Cannot find free slot for GRE Tunnel session stats, I/F:%u\n", nss_ctx, if_num);
	return NULL;
	}

	if (nss_ctx->subsys_dp_register[if_num].ndev) {
	nss_warning("%px: Cannot find free slot for GRE Tunnel NSS I/F:%u\n", nss_ctx, if_num);
	session_stats[i].valid = false;
	session_stats[i].if_num = 0;
	session_stats[i].if_index = 0;
	return NULL;
	}

	nss_core_register_subsys_dp(nss_ctx, if_num, cb, NULL, app_ctx, netdev, features);

	nss_top_main.gre_tunnel_msg_callback = ev_cb;
	nss_core_register_handler(nss_ctx, if_num, nss_gre_tunnel_handler, app_ctx);
	nss_gre_tunnel_stats_dentry_create();
	nss_gre_tunnel_strings_dentry_create();

	return nss_ctx;
	}
	EXPORT_SYMBOL(nss_gre_tunnel_register_if);

	/*
	* nss_gre_tunnel_unregister_if()
	* Unregister netdev
	*/
	void nss_gre_tunnel_unregister_if(uint32_t if_num)
	{
	int32_t i;
	struct nss_ctx_instance *nss_ctx = nss_gre_tunnel_get_ctx();

	BUG_ON(!nss_gre_tunnel_verify_if_num(if_num));

	spin_lock_bh(&nss_gre_tunnel_stats_lock);
	for (i = 0; i < NSS_MAX_GRE_TUNNEL_SESSIONS; i++) {
	if (session_stats[i].if_num == if_num) {
	memset(&session_stats[i], 0,
	sizeof(struct nss_gre_tunnel_stats_session));
	break;
	}
	}
	spin_unlock_bh(&nss_gre_tunnel_stats_lock);

	if (i == NSS_MAX_GRE_TUNNEL_SESSIONS) {
	nss_warning("%px: Cannot find debug stats for GRE Tunnel session: %d\n", nss_ctx, if_num);
	return;
	}

	if (!nss_ctx->subsys_dp_register[if_num].ndev) {
	nss_warning("%px: Cannot find registered netdev for GRE Tunnel NSS I/F: %d\n", nss_ctx, if_num);

	return;
	}

	nss_core_unregister_subsys_dp(nss_ctx, if_num);

	nss_top_main.gre_tunnel_msg_callback = NULL;
	nss_core_unregister_handler(nss_ctx, if_num);
	}
	EXPORT_SYMBOL(nss_gre_tunnel_unregister_if);