drivers/net/wwan/iosm/iosm_ipc_mux.h - linux - Git at Google

 /* SPDX-License-Identifier: GPL-2.0-only
  *
  * Copyright (C) 2020-21 Intel Corporation.
  */

 #ifndef IOSM_IPC_MUX_H
 #define IOSM_IPC_MUX_H

 #include "iosm_ipc_protocol.h"

 /* Size of the buffer for the IP MUX data buffer. */
 #define IPC_MEM_MAX_DL_MUX_BUF_SIZE (16 * 1024)
 #define IPC_MEM_MAX_UL_ADB_BUF_SIZE IPC_MEM_MAX_DL_MUX_BUF_SIZE

 /* Size of the buffer for the IP MUX Lite data buffer. */
 #define IPC_MEM_MAX_DL_MUX_LITE_BUF_SIZE (2 * 1024)

 /* TD counts for IP MUX Lite */
 #define IPC_MEM_MAX_TDS_MUX_LITE_UL 800
 #define IPC_MEM_MAX_TDS_MUX_LITE_DL 1200

 /* open session request (AP->CP) */
 #define MUX_CMD_OPEN_SESSION 1

 /* response to open session request (CP->AP) */
 #define MUX_CMD_OPEN_SESSION_RESP 2

 /* close session request (AP->CP) */
 #define MUX_CMD_CLOSE_SESSION 3

 /* response to close session request (CP->AP) */
 #define MUX_CMD_CLOSE_SESSION_RESP 4

 /* Flow control command with mask of the flow per queue/flow. */
 #define MUX_LITE_CMD_FLOW_CTL 5

 /* ACK the flow control command. Shall have the same Transaction ID as the
  * matching FLOW_CTL command.
  */
 #define MUX_LITE_CMD_FLOW_CTL_ACK 6

 /* Command for report packet indicating link quality metrics. */
 #define MUX_LITE_CMD_LINK_STATUS_REPORT 7

 /* Response to a report packet */
 #define MUX_LITE_CMD_LINK_STATUS_REPORT_RESP 8

 /* Used to reset a command/response state. */
 #define MUX_CMD_INVALID 255

 /* command response : command processed successfully */
 #define MUX_CMD_RESP_SUCCESS 0

 /* MUX for route link devices */
 #define IPC_MEM_WWAN_MUX BIT(0)

 /* Initiated actions to change the state of the MUX object. */
 enum mux_event {
 	MUX_E_INACTIVE, /* No initiated actions. */
 	MUX_E_MUX_SESSION_OPEN, /* Create the MUX channel and a session. */
 	MUX_E_MUX_SESSION_CLOSE, /* Release a session. */
 	MUX_E_MUX_CHANNEL_CLOSE, /* Release the MUX channel. */
 	MUX_E_NO_ORDERS, /* No MUX order. */
 	MUX_E_NOT_APPLICABLE, /* Defect IP MUX. */
 };

 /* MUX session open command. */
 struct mux_session_open {
 	enum mux_event event;
 	__le32 if_id;
 };

 /* MUX session close command. */
 struct mux_session_close {
 	enum mux_event event;
 	__le32 if_id;
 };

 /* MUX channel close command. */
 struct mux_channel_close {
 	enum mux_event event;
 };

 /* Default message type to find out the right message type. */
 struct mux_common {
 	enum mux_event event;
 };

 /* List of ops in MUX mode. */
 union mux_msg {
 	struct mux_session_open session_open;
 	struct mux_session_close session_close;
 	struct mux_channel_close channel_close;
 	struct mux_common common;
 };

 /* Parameter definition of the open session command. */
 struct mux_cmd_open_session {
 	u8 flow_ctrl; /* 0: Flow control disabled (flow allowed). */
 	/* 1: Flow control enabled (flow not allowed)*/
 	u8 ipv4v6_hints; /* 0: IPv4/IPv6 hints not supported.*/
 	/* 1: IPv4/IPv6 hints supported*/
 	__le16 reserved2; /* Reserved. Set to zero. */
 	__le32 dl_head_pad_len; /* Maximum length supported */
 	/* for DL head padding on a datagram. */
 };

 /* Parameter definition of the open session response. */
 struct mux_cmd_open_session_resp {
 	__le32 response; /* Response code */
 	u8 flow_ctrl; /* 0: Flow control disabled (flow allowed). */
 	/* 1: Flow control enabled (flow not allowed) */
 	u8 ipv4v6_hints; /* 0: IPv4/IPv6 hints not supported */
 	/* 1: IPv4/IPv6 hints supported */
 	__le16 reserved2; /* Reserved. Set to zero. */
 	__le32 ul_head_pad_len; /* Actual length supported for */
 	/* UL head padding on adatagram.*/
 };

 /* Parameter definition of the close session response code */
 struct mux_cmd_close_session_resp {
 	__le32 response;
 };

 /* Parameter definition of the flow control command. */
 struct mux_cmd_flow_ctl {
 	__le32 mask; /* indicating the desired flow control */
 	/* state for various flows/queues */
 };

 /* Parameter definition of the link status report code*/
 struct mux_cmd_link_status_report {
 	u8 payload;
 };

 /* Parameter definition of the link status report response code. */
 struct mux_cmd_link_status_report_resp {
 	__le32 response;
 };

 /**
  * union mux_cmd_param - Union-definition of the command parameters.
  * @open_session:	Inband command for open session
  * @open_session_resp:	Inband command for open session response
  * @close_session_resp:	Inband command for close session response
  * @flow_ctl:		In-band flow control on the opened interfaces
  * @link_status:	In-band Link Status Report
  * @link_status_resp:	In-band command for link status report response
  */
 union mux_cmd_param {
 	struct mux_cmd_open_session open_session;
 	struct mux_cmd_open_session_resp open_session_resp;
 	struct mux_cmd_close_session_resp close_session_resp;
 	struct mux_cmd_flow_ctl flow_ctl;
 	struct mux_cmd_link_status_report link_status;
 	struct mux_cmd_link_status_report_resp link_status_resp;
 };

 /* States of the MUX object.. */
 enum mux_state {
 	MUX_S_INACTIVE, /* IP MUX is unused. */
 	MUX_S_ACTIVE, /* IP MUX channel is available. */
 	MUX_S_ERROR, /* Defect IP MUX. */
 };

 /* Supported MUX protocols. */
 enum ipc_mux_protocol {
 	MUX_UNKNOWN,
 	MUX_LITE,
 };

 /* Supported UL data transfer methods. */
 enum ipc_mux_ul_flow {
 	MUX_UL_UNKNOWN,
 	MUX_UL, /* Normal UL data transfer */
 	MUX_UL_ON_CREDITS, /* UL data transfer will be based on credits */
 };

 /* List of the MUX session. */
 struct mux_session {
 	struct iosm_wwan *wwan; /*Network i/f used for communication*/
 	int if_id; /* i/f id for session open message.*/
 	u32 flags;
 	u32 ul_head_pad_len; /* Nr of bytes for UL head padding. */
 	u32 dl_head_pad_len; /* Nr of bytes for DL head padding. */
 	struct sk_buff_head ul_list; /* skb entries for an ADT. */
 	u32 flow_ctl_mask; /* UL flow control */
 	u32 flow_ctl_en_cnt; /* Flow control Enable cmd count */
 	u32 flow_ctl_dis_cnt; /* Flow Control Disable cmd count */
 	int ul_flow_credits; /* UL flow credits */
 	u8 net_tx_stop:1,
 	   flush:1; /* flush net interface ? */
 };

 /* State of a single UL data block. */
 struct mux_adb {
 	struct sk_buff *dest_skb; /* Current UL skb for the data block. */
 	u8 *buf; /* ADB memory. */
 	struct mux_adgh *adgh; /* ADGH pointer */
 	struct sk_buff *qlth_skb; /* QLTH pointer */
 	u32 *next_table_index; /* Pointer to next table index. */
 	struct sk_buff_head free_list; /* List of alloc. ADB for the UL sess.*/
 	int size; /* Size of the ADB memory. */
 	u32 if_cnt; /* Statistic counter */
 	u32 dg_cnt_total;
 	u32 payload_size;
 };

 /* Temporary ACB state. */
 struct mux_acb {
 	struct sk_buff *skb; /* Used UL skb. */
 	int if_id; /* Session id. */
 	u32 wanted_response;
 	u32 got_response;
 	u32 cmd;
 	union mux_cmd_param got_param; /* Received command/response parameter */
 };

 /**
  * struct iosm_mux - Structure of the data multiplexing over an IP channel.
  * @dev:		Pointer to device structure
  * @session:		Array of the MUX sessions.
  * @channel:		Reference to the IP MUX channel
  * @pcie:		Pointer to iosm_pcie struct
  * @imem:		Pointer to iosm_imem
  * @wwan:		Poinetr to iosm_wwan
  * @ipc_protocol:	Pointer to iosm_protocol
  * @channel_id:		Channel ID for MUX
  * @protocol:		Type of the MUX protocol
  * @ul_flow:		UL Flow type
  * @nr_sessions:	Number of sessions
  * @instance_id:	Instance ID
  * @state:		States of the MUX object
  * @event:		Initiated actions to change the state of the MUX object
  * @tx_transaction_id:	Transaction id for the ACB command.
  * @rr_next_session:	Next session number for round robin.
  * @ul_adb:		State of the UL ADB/ADGH.
  * @size_needed:	Variable to store the size needed during ADB preparation
  * @ul_data_pend_bytes:	Pending UL data to be processed in bytes
  * @acb:		Temporary ACB state
  * @wwan_q_offset:	This will hold the offset of the given instance
  *			Useful while passing or receiving packets from
  *			wwan/imem layer.
  * @initialized:	MUX object is initialized
  * @ev_mux_net_transmit_pending:
  *			0 means inform the IPC tasklet to pass the
  *			accumulated uplink ADB to CP.
  * @adb_prep_ongoing:	Flag for ADB preparation status
  */
 struct iosm_mux {
 	struct device *dev;
 	struct mux_session session[IPC_MEM_MUX_IP_SESSION_ENTRIES];
 	struct ipc_mem_channel *channel;
 	struct iosm_pcie *pcie;
 	struct iosm_imem *imem;
 	struct iosm_wwan *wwan;
 	struct iosm_protocol *ipc_protocol;
 	int channel_id;
 	enum ipc_mux_protocol protocol;
 	enum ipc_mux_ul_flow ul_flow;
 	int nr_sessions;
 	int instance_id;
 	enum mux_state state;
 	enum mux_event event;
 	u32 tx_transaction_id;
 	int rr_next_session;
 	struct mux_adb ul_adb;
 	int size_needed;
 	long long ul_data_pend_bytes;
 	struct mux_acb acb;
 	int wwan_q_offset;
 	u8 initialized:1,
 	   ev_mux_net_transmit_pending:1,
 	   adb_prep_ongoing:1;
 };

 /* MUX configuration structure */
 struct ipc_mux_config {
 	enum ipc_mux_protocol protocol;
 	enum ipc_mux_ul_flow ul_flow;
 	int nr_sessions;
 	int instance_id;
 };

 /**
  * ipc_mux_init - Allocates and Init MUX instance
  * @mux_cfg:	Pointer to MUX configuration structure
  * @ipc_imem:	Pointer to imem data-struct
  *
  * Returns: Initialized mux pointer on success else NULL
  */
 struct iosm_mux *ipc_mux_init(struct ipc_mux_config *mux_cfg,
 			      struct iosm_imem *ipc_imem);

 /**
  * ipc_mux_deinit - Deallocates MUX instance
  * @ipc_mux:	Pointer to the MUX instance.
  */
 void ipc_mux_deinit(struct iosm_mux *ipc_mux);

 /**
  * ipc_mux_check_n_restart_tx - Checks for pending UL date bytes and then
  *				it restarts the net interface tx queue if
  *				device has set flow control as off.
  * @ipc_mux:	Pointer to MUX data-struct
  */
 void ipc_mux_check_n_restart_tx(struct iosm_mux *ipc_mux);

 /**
  * ipc_mux_get_active_protocol - Returns the active MUX protocol type.
  * @ipc_mux:	Pointer to MUX data-struct
  *
  * Returns: enum of type ipc_mux_protocol
  */
 enum ipc_mux_protocol ipc_mux_get_active_protocol(struct iosm_mux *ipc_mux);

 /**
  * ipc_mux_open_session - Opens a MUX session for IP traffic.
  * @ipc_mux:	Pointer to MUX data-struct
  * @session_nr:	Interface ID or session number
  *
  * Returns: channel id on success, failure value on error
  */
 int ipc_mux_open_session(struct iosm_mux *ipc_mux, int session_nr);

 /**
  * ipc_mux_close_session - Closes a MUX session.
  * @ipc_mux:	Pointer to MUX data-struct
  * @session_nr:	Interface ID or session number
  *
  * Returns: channel id on success, failure value on error
  */
 int ipc_mux_close_session(struct iosm_mux *ipc_mux, int session_nr);

 /**
  * ipc_mux_get_max_sessions - Retuns the maximum sessions supported on the
  *			      provided MUX instance..
  * @ipc_mux:	Pointer to MUX data-struct
  *
  * Returns: Number of sessions supported on Success and failure value on error
  */
 int ipc_mux_get_max_sessions(struct iosm_mux *ipc_mux);
 #endif
	/* SPDX-License-Identifier: GPL-2.0-only
	*
	* Copyright (C) 2020-21 Intel Corporation.
	*/

	#ifndef IOSM_IPC_MUX_H
	#define IOSM_IPC_MUX_H

	#include "iosm_ipc_protocol.h"

	/* Size of the buffer for the IP MUX data buffer. */
	#define IPC_MEM_MAX_DL_MUX_BUF_SIZE (16 * 1024)
	#define IPC_MEM_MAX_UL_ADB_BUF_SIZE IPC_MEM_MAX_DL_MUX_BUF_SIZE

	/* Size of the buffer for the IP MUX Lite data buffer. */
	#define IPC_MEM_MAX_DL_MUX_LITE_BUF_SIZE (2 * 1024)

	/* TD counts for IP MUX Lite */
	#define IPC_MEM_MAX_TDS_MUX_LITE_UL 800
	#define IPC_MEM_MAX_TDS_MUX_LITE_DL 1200

	/* open session request (AP->CP) */
	#define MUX_CMD_OPEN_SESSION 1

	/* response to open session request (CP->AP) */
	#define MUX_CMD_OPEN_SESSION_RESP 2

	/* close session request (AP->CP) */
	#define MUX_CMD_CLOSE_SESSION 3

	/* response to close session request (CP->AP) */
	#define MUX_CMD_CLOSE_SESSION_RESP 4

	/* Flow control command with mask of the flow per queue/flow. */
	#define MUX_LITE_CMD_FLOW_CTL 5

	/* ACK the flow control command. Shall have the same Transaction ID as the
	* matching FLOW_CTL command.
	*/
	#define MUX_LITE_CMD_FLOW_CTL_ACK 6

	/* Command for report packet indicating link quality metrics. */
	#define MUX_LITE_CMD_LINK_STATUS_REPORT 7

	/* Response to a report packet */
	#define MUX_LITE_CMD_LINK_STATUS_REPORT_RESP 8

	/* Used to reset a command/response state. */
	#define MUX_CMD_INVALID 255

	/* command response : command processed successfully */
	#define MUX_CMD_RESP_SUCCESS 0

	/* MUX for route link devices */
	#define IPC_MEM_WWAN_MUX BIT(0)

	/* Initiated actions to change the state of the MUX object. */
	enum mux_event {
	MUX_E_INACTIVE, /* No initiated actions. */
	MUX_E_MUX_SESSION_OPEN, /* Create the MUX channel and a session. */
	MUX_E_MUX_SESSION_CLOSE, /* Release a session. */
	MUX_E_MUX_CHANNEL_CLOSE, /* Release the MUX channel. */
	MUX_E_NO_ORDERS, /* No MUX order. */
	MUX_E_NOT_APPLICABLE, /* Defect IP MUX. */
	};

	/* MUX session open command. */
	struct mux_session_open {
	enum mux_event event;
	__le32 if_id;
	};

	/* MUX session close command. */
	struct mux_session_close {
	enum mux_event event;
	__le32 if_id;
	};

	/* MUX channel close command. */
	struct mux_channel_close {
	enum mux_event event;
	};

	/* Default message type to find out the right message type. */
	struct mux_common {
	enum mux_event event;
	};

	/* List of ops in MUX mode. */
	union mux_msg {
	struct mux_session_open session_open;
	struct mux_session_close session_close;
	struct mux_channel_close channel_close;
	struct mux_common common;
	};

	/* Parameter definition of the open session command. */
	struct mux_cmd_open_session {
	u8 flow_ctrl; /* 0: Flow control disabled (flow allowed). */
	/* 1: Flow control enabled (flow not allowed)*/
	u8 ipv4v6_hints; /* 0: IPv4/IPv6 hints not supported.*/
	/* 1: IPv4/IPv6 hints supported*/
	__le16 reserved2; /* Reserved. Set to zero. */
	__le32 dl_head_pad_len; /* Maximum length supported */
	/* for DL head padding on a datagram. */
	};

	/* Parameter definition of the open session response. */
	struct mux_cmd_open_session_resp {
	__le32 response; /* Response code */
	u8 flow_ctrl; /* 0: Flow control disabled (flow allowed). */
	/* 1: Flow control enabled (flow not allowed) */
	u8 ipv4v6_hints; /* 0: IPv4/IPv6 hints not supported */
	/* 1: IPv4/IPv6 hints supported */
	__le16 reserved2; /* Reserved. Set to zero. */
	__le32 ul_head_pad_len; /* Actual length supported for */
	/* UL head padding on adatagram.*/
	};

	/* Parameter definition of the close session response code */
	struct mux_cmd_close_session_resp {
	__le32 response;
	};

	/* Parameter definition of the flow control command. */
	struct mux_cmd_flow_ctl {
	__le32 mask; /* indicating the desired flow control */
	/* state for various flows/queues */
	};

	/* Parameter definition of the link status report code*/
	struct mux_cmd_link_status_report {
	u8 payload;
	};

	/* Parameter definition of the link status report response code. */
	struct mux_cmd_link_status_report_resp {
	__le32 response;
	};

	/**
	* union mux_cmd_param - Union-definition of the command parameters.
	* @open_session: Inband command for open session
	* @open_session_resp: Inband command for open session response
	* @close_session_resp: Inband command for close session response
	* @flow_ctl: In-band flow control on the opened interfaces
	* @link_status: In-band Link Status Report
	* @link_status_resp: In-band command for link status report response
	*/
	union mux_cmd_param {
	struct mux_cmd_open_session open_session;
	struct mux_cmd_open_session_resp open_session_resp;
	struct mux_cmd_close_session_resp close_session_resp;
	struct mux_cmd_flow_ctl flow_ctl;
	struct mux_cmd_link_status_report link_status;
	struct mux_cmd_link_status_report_resp link_status_resp;
	};

	/* States of the MUX object.. */
	enum mux_state {
	MUX_S_INACTIVE, /* IP MUX is unused. */
	MUX_S_ACTIVE, /* IP MUX channel is available. */
	MUX_S_ERROR, /* Defect IP MUX. */
	};

	/* Supported MUX protocols. */
	enum ipc_mux_protocol {
	MUX_UNKNOWN,
	MUX_LITE,
	};

	/* Supported UL data transfer methods. */
	enum ipc_mux_ul_flow {
	MUX_UL_UNKNOWN,
	MUX_UL, /* Normal UL data transfer */
	MUX_UL_ON_CREDITS, /* UL data transfer will be based on credits */
	};

	/* List of the MUX session. */
	struct mux_session {
	struct iosm_wwan wwan; /Network i/f used for communication*/
	int if_id; /* i/f id for session open message.*/
	u32 flags;
	u32 ul_head_pad_len; /* Nr of bytes for UL head padding. */
	u32 dl_head_pad_len; /* Nr of bytes for DL head padding. */
	struct sk_buff_head ul_list; /* skb entries for an ADT. */
	u32 flow_ctl_mask; /* UL flow control */
	u32 flow_ctl_en_cnt; /* Flow control Enable cmd count */
	u32 flow_ctl_dis_cnt; /* Flow Control Disable cmd count */
	int ul_flow_credits; /* UL flow credits */
	u8 net_tx_stop:1,
	flush:1; /* flush net interface ? */
	};

	/* State of a single UL data block. */
	struct mux_adb {
	struct sk_buff dest_skb; / Current UL skb for the data block. */
	u8 buf; / ADB memory. */
	struct mux_adgh adgh; / ADGH pointer */
	struct sk_buff qlth_skb; / QLTH pointer */
	u32 next_table_index; / Pointer to next table index. */
	struct sk_buff_head free_list; /* List of alloc. ADB for the UL sess.*/
	int size; /* Size of the ADB memory. */
	u32 if_cnt; /* Statistic counter */
	u32 dg_cnt_total;
	u32 payload_size;
	};

	/* Temporary ACB state. */
	struct mux_acb {
	struct sk_buff skb; / Used UL skb. */
	int if_id; /* Session id. */
	u32 wanted_response;
	u32 got_response;
	u32 cmd;
	union mux_cmd_param got_param; /* Received command/response parameter */
	};

	/**
	* struct iosm_mux - Structure of the data multiplexing over an IP channel.
	* @dev: Pointer to device structure
	* @session: Array of the MUX sessions.
	* @channel: Reference to the IP MUX channel
	* @pcie: Pointer to iosm_pcie struct
	* @imem: Pointer to iosm_imem
	* @wwan: Poinetr to iosm_wwan
	* @ipc_protocol: Pointer to iosm_protocol
	* @channel_id: Channel ID for MUX
	* @protocol: Type of the MUX protocol
	* @ul_flow: UL Flow type
	* @nr_sessions: Number of sessions
	* @instance_id: Instance ID
	* @state: States of the MUX object
	* @event: Initiated actions to change the state of the MUX object
	* @tx_transaction_id: Transaction id for the ACB command.
	* @rr_next_session: Next session number for round robin.
	* @ul_adb: State of the UL ADB/ADGH.
	* @size_needed: Variable to store the size needed during ADB preparation
	* @ul_data_pend_bytes: Pending UL data to be processed in bytes
	* @acb: Temporary ACB state
	* @wwan_q_offset: This will hold the offset of the given instance
	* Useful while passing or receiving packets from
	* wwan/imem layer.
	* @initialized: MUX object is initialized
	* @ev_mux_net_transmit_pending:
	* 0 means inform the IPC tasklet to pass the
	* accumulated uplink ADB to CP.
	* @adb_prep_ongoing: Flag for ADB preparation status
	*/
	struct iosm_mux {
	struct device *dev;
	struct mux_session session[IPC_MEM_MUX_IP_SESSION_ENTRIES];
	struct ipc_mem_channel *channel;
	struct iosm_pcie *pcie;
	struct iosm_imem *imem;
	struct iosm_wwan *wwan;
	struct iosm_protocol *ipc_protocol;
	int channel_id;
	enum ipc_mux_protocol protocol;
	enum ipc_mux_ul_flow ul_flow;
	int nr_sessions;
	int instance_id;
	enum mux_state state;
	enum mux_event event;
	u32 tx_transaction_id;
	int rr_next_session;
	struct mux_adb ul_adb;
	int size_needed;
	long long ul_data_pend_bytes;
	struct mux_acb acb;
	int wwan_q_offset;
	u8 initialized:1,
	ev_mux_net_transmit_pending:1,
	adb_prep_ongoing:1;
	};

	/* MUX configuration structure */
	struct ipc_mux_config {
	enum ipc_mux_protocol protocol;
	enum ipc_mux_ul_flow ul_flow;
	int nr_sessions;
	int instance_id;
	};

	/**
	* ipc_mux_init - Allocates and Init MUX instance
	* @mux_cfg: Pointer to MUX configuration structure
	* @ipc_imem: Pointer to imem data-struct
	*
	* Returns: Initialized mux pointer on success else NULL
	*/
	struct iosm_mux ipc_mux_init(struct ipc_mux_config mux_cfg,
	struct iosm_imem *ipc_imem);

	/**
	* ipc_mux_deinit - Deallocates MUX instance
	* @ipc_mux: Pointer to the MUX instance.
	*/
	void ipc_mux_deinit(struct iosm_mux *ipc_mux);

	/**
	* ipc_mux_check_n_restart_tx - Checks for pending UL date bytes and then
	* it restarts the net interface tx queue if
	* device has set flow control as off.
	* @ipc_mux: Pointer to MUX data-struct
	*/
	void ipc_mux_check_n_restart_tx(struct iosm_mux *ipc_mux);

	/**
	* ipc_mux_get_active_protocol - Returns the active MUX protocol type.
	* @ipc_mux: Pointer to MUX data-struct
	*
	* Returns: enum of type ipc_mux_protocol
	*/
	enum ipc_mux_protocol ipc_mux_get_active_protocol(struct iosm_mux *ipc_mux);

	/**
	* ipc_mux_open_session - Opens a MUX session for IP traffic.
	* @ipc_mux: Pointer to MUX data-struct
	* @session_nr: Interface ID or session number
	*
	* Returns: channel id on success, failure value on error
	*/
	int ipc_mux_open_session(struct iosm_mux *ipc_mux, int session_nr);

	/**
	* ipc_mux_close_session - Closes a MUX session.
	* @ipc_mux: Pointer to MUX data-struct
	* @session_nr: Interface ID or session number
	*
	* Returns: channel id on success, failure value on error
	*/
	int ipc_mux_close_session(struct iosm_mux *ipc_mux, int session_nr);

	/**
	* ipc_mux_get_max_sessions - Retuns the maximum sessions supported on the
	* provided MUX instance..
	* @ipc_mux: Pointer to MUX data-struct
	*
	* Returns: Number of sessions supported on Success and failure value on error
	*/
	int ipc_mux_get_max_sessions(struct iosm_mux *ipc_mux);
	#endif