net: iosm: multiplex IP sessions

// SPDX-License-Identifier: GPL-2.0-only

/*

 * Copyright (C) 2020-21 Intel Corporation.

 */

#include "iosm_ipc_mux_codec.h"

/* At the begin of the runtime phase the IP MUX channel shall created. */

static int ipc_mux_channel_create(struct iosm_mux *ipc_mux)

{

	int channel_id;

	channel_id = ipc_imem_channel_alloc(ipc_mux->imem, ipc_mux->instance_id,

					    IPC_CTYPE_WWAN);

	if (channel_id < 0) {

		dev_err(ipc_mux->dev,

			"allocation of the MUX channel id failed");

		ipc_mux->state = MUX_S_ERROR;

		ipc_mux->event = MUX_E_NOT_APPLICABLE;

		goto no_channel;

	}

	/* Establish the MUX channel in blocking mode. */

	ipc_mux->channel = ipc_imem_channel_open(ipc_mux->imem, channel_id,

						 IPC_HP_NET_CHANNEL_INIT);

	if (!ipc_mux->channel) {

		dev_err(ipc_mux->dev, "ipc_imem_channel_open failed");

		ipc_mux->state = MUX_S_ERROR;

		ipc_mux->event = MUX_E_NOT_APPLICABLE;

		return -ENODEV; /* MUX channel is not available. */

	}

	/* Define the MUX active state properties. */

	ipc_mux->state = MUX_S_ACTIVE;

	ipc_mux->event = MUX_E_NO_ORDERS;

no_channel:

	return channel_id;

}

/* Reset the session/if id state. */

static void ipc_mux_session_free(struct iosm_mux *ipc_mux, int if_id)

{

	struct mux_session *if_entry;

	if_entry = &ipc_mux->session[if_id];

	/* Reset the session state. */

	if_entry->wwan = NULL;

}

/* Create and send the session open command. */

static struct mux_cmd_open_session_resp *

ipc_mux_session_open_send(struct iosm_mux *ipc_mux, int if_id)

{

	struct mux_cmd_open_session_resp *open_session_resp;

	struct mux_acb *acb = &ipc_mux->acb;

	union mux_cmd_param param;

	/* open_session commands to one ACB and start transmission. */

	param.open_session.flow_ctrl = 0;

	param.open_session.ipv4v6_hints = 0;

	param.open_session.reserved2 = 0;

	param.open_session.dl_head_pad_len = cpu_to_le32(IPC_MEM_DL_ETH_OFFSET);

	/* Finish and transfer ACB. The user thread is suspended.

	 * It is a blocking function call, until CP responds or timeout.

	 */

	acb->wanted_response = MUX_CMD_OPEN_SESSION_RESP;

	if (ipc_mux_dl_acb_send_cmds(ipc_mux, MUX_CMD_OPEN_SESSION, if_id, 0,

				     &param, sizeof(param.open_session), true,

				 false) ||

	    acb->got_response != MUX_CMD_OPEN_SESSION_RESP) {

		dev_err(ipc_mux->dev, "if_id %d: OPEN_SESSION send failed",

			if_id);

		return NULL;

	}

	open_session_resp = &ipc_mux->acb.got_param.open_session_resp;

	if (open_session_resp->response != cpu_to_le32(MUX_CMD_RESP_SUCCESS)) {

		dev_err(ipc_mux->dev,

			"if_id %d,session open failed,response=%d", if_id,

			open_session_resp->response);

		return NULL;

	}

	return open_session_resp;

}

/* Open the first IP session. */

static bool ipc_mux_session_open(struct iosm_mux *ipc_mux,

				 struct mux_session_open *session_open)

{

	struct mux_cmd_open_session_resp *open_session_resp;

	int if_id;

	/* Search for a free session interface id. */

	if_id = le32_to_cpu(session_open->if_id);

	if (if_id < 0 || if_id >= ipc_mux->nr_sessions) {

		dev_err(ipc_mux->dev, "invalid interface id=%d", if_id);

		return false;

	}

	/* Create and send the session open command.

	 * It is a blocking function call, until CP responds or timeout.

	 */

	open_session_resp = ipc_mux_session_open_send(ipc_mux, if_id);

	if (!open_session_resp) {

		ipc_mux_session_free(ipc_mux, if_id);

		session_open->if_id = cpu_to_le32(-1);

		return false;

	}

	/* Initialize the uplink skb accumulator. */

	skb_queue_head_init(&ipc_mux->session[if_id].ul_list);

	ipc_mux->session[if_id].dl_head_pad_len = IPC_MEM_DL_ETH_OFFSET;

	ipc_mux->session[if_id].ul_head_pad_len =

		le32_to_cpu(open_session_resp->ul_head_pad_len);

	ipc_mux->session[if_id].wwan = ipc_mux->wwan;

	/* Reset the flow ctrl stats of the session */

	ipc_mux->session[if_id].flow_ctl_en_cnt = 0;

	ipc_mux->session[if_id].flow_ctl_dis_cnt = 0;

	ipc_mux->session[if_id].ul_flow_credits = 0;

	ipc_mux->session[if_id].net_tx_stop = false;

	ipc_mux->session[if_id].flow_ctl_mask = 0;

	/* Save and return the assigned if id. */

	session_open->if_id = cpu_to_le32(if_id);

	return true;

}

/* Free pending session UL packet. */

static void ipc_mux_session_reset(struct iosm_mux *ipc_mux, int if_id)

{

	/* Reset the session/if id state. */

	ipc_mux_session_free(ipc_mux, if_id);

	/* Empty the uplink skb accumulator. */

	skb_queue_purge(&ipc_mux->session[if_id].ul_list);

}

static void ipc_mux_session_close(struct iosm_mux *ipc_mux,

				  struct mux_session_close *msg)

{

	int if_id;

	/* Copy the session interface id. */

	if_id = le32_to_cpu(msg->if_id);

	if (if_id < 0 || if_id >= ipc_mux->nr_sessions) {

		dev_err(ipc_mux->dev, "invalid session id %d", if_id);

		return;

	}

	/* Create and send the session close command.

	 * It is a blocking function call, until CP responds or timeout.

	 */

	if (ipc_mux_dl_acb_send_cmds(ipc_mux, MUX_CMD_CLOSE_SESSION, if_id, 0,

				     NULL, 0, true, false))

		dev_err(ipc_mux->dev, "if_id %d: CLOSE_SESSION send failed",

			if_id);

	/* Reset the flow ctrl stats of the session */

	ipc_mux->session[if_id].flow_ctl_en_cnt = 0;

	ipc_mux->session[if_id].flow_ctl_dis_cnt = 0;

	ipc_mux->session[if_id].flow_ctl_mask = 0;

	ipc_mux_session_reset(ipc_mux, if_id);

}

static void ipc_mux_channel_close(struct iosm_mux *ipc_mux,

				  struct mux_channel_close *channel_close_p)

{

	int i;

	/* Free pending session UL packet. */

	for (i = 0; i < ipc_mux->nr_sessions; i++)

		if (ipc_mux->session[i].wwan)

			ipc_mux_session_reset(ipc_mux, i);

	ipc_imem_channel_close(ipc_mux->imem, ipc_mux->channel_id);

	/* Reset the MUX object. */

	ipc_mux->state = MUX_S_INACTIVE;

	ipc_mux->event = MUX_E_INACTIVE;

}

/* CP has interrupted AP. If AP is in IP MUX mode, execute the pending ops. */

static int ipc_mux_schedule(struct iosm_mux *ipc_mux, union mux_msg *msg)

{

	enum mux_event order;

	bool success;

	int ret = -EIO;

	if (!ipc_mux->initialized) {

		ret = -EAGAIN;

		goto out;

	}

	order = msg->common.event;

	switch (ipc_mux->state) {

	case MUX_S_INACTIVE:

		if (order != MUX_E_MUX_SESSION_OPEN)

			goto out; /* Wait for the request to open a session */

		if (ipc_mux->event == MUX_E_INACTIVE)

			/* Establish the MUX channel and the new state. */

			ipc_mux->channel_id = ipc_mux_channel_create(ipc_mux);

		if (ipc_mux->state != MUX_S_ACTIVE) {

			ret = ipc_mux->channel_id; /* Missing the MUX channel */

			goto out;

		}

		/* Disable the TD update timer and open the first IP session. */

		ipc_imem_td_update_timer_suspend(ipc_mux->imem, true);

		ipc_mux->event = MUX_E_MUX_SESSION_OPEN;

		success = ipc_mux_session_open(ipc_mux, &msg->session_open);

		ipc_imem_td_update_timer_suspend(ipc_mux->imem, false);

		if (success)

			ret = ipc_mux->channel_id;

		goto out;

	case MUX_S_ACTIVE:

		switch (order) {

		case MUX_E_MUX_SESSION_OPEN:

			/* Disable the TD update timer and open a session */

			ipc_imem_td_update_timer_suspend(ipc_mux->imem, true);

			ipc_mux->event = MUX_E_MUX_SESSION_OPEN;

			success = ipc_mux_session_open(ipc_mux,

						       &msg->session_open);

			ipc_imem_td_update_timer_suspend(ipc_mux->imem, false);

			if (success)

				ret = ipc_mux->channel_id;

			goto out;

		case MUX_E_MUX_SESSION_CLOSE:

			/* Release an IP session. */

			ipc_mux->event = MUX_E_MUX_SESSION_CLOSE;

			ipc_mux_session_close(ipc_mux, &msg->session_close);

			ret = ipc_mux->channel_id;

			goto out;

		case MUX_E_MUX_CHANNEL_CLOSE:

			/* Close the MUX channel pipes. */

			ipc_mux->event = MUX_E_MUX_CHANNEL_CLOSE;

			ipc_mux_channel_close(ipc_mux, &msg->channel_close);

			ret = ipc_mux->channel_id;

			goto out;

		default:

			/* Invalid order. */

			goto out;

		}

	default:

		dev_err(ipc_mux->dev,

			"unexpected MUX transition: state=%d, event=%d",

			ipc_mux->state, ipc_mux->event);

	}

out:

	return ret;

}

struct iosm_mux *ipc_mux_init(struct ipc_mux_config *mux_cfg,

			      struct iosm_imem *imem)

{

	struct iosm_mux *ipc_mux = kzalloc(sizeof(*ipc_mux), GFP_KERNEL);

	int i, ul_tds, ul_td_size;

	struct sk_buff_head *free_list;

	struct sk_buff *skb;

	if (!ipc_mux)

		return NULL;

	ipc_mux->protocol = mux_cfg->protocol;

	ipc_mux->ul_flow = mux_cfg->ul_flow;

	ipc_mux->nr_sessions = mux_cfg->nr_sessions;

	ipc_mux->instance_id = mux_cfg->instance_id;

	ipc_mux->wwan_q_offset = 0;

	ipc_mux->pcie = imem->pcie;

	ipc_mux->imem = imem;

	ipc_mux->ipc_protocol = imem->ipc_protocol;

	ipc_mux->dev = imem->dev;

	ipc_mux->wwan = imem->wwan;

	/* Get the reference to the UL ADB list. */

	free_list = &ipc_mux->ul_adb.free_list;

	/* Initialize the list with free ADB. */

	skb_queue_head_init(free_list);

	ul_td_size = IPC_MEM_MAX_DL_MUX_LITE_BUF_SIZE;

	ul_tds = IPC_MEM_MAX_TDS_MUX_LITE_UL;

	ipc_mux->ul_adb.dest_skb = NULL;

	ipc_mux->initialized = true;

	ipc_mux->adb_prep_ongoing = false;

	ipc_mux->size_needed = 0;

	ipc_mux->ul_data_pend_bytes = 0;

	ipc_mux->state = MUX_S_INACTIVE;

	ipc_mux->ev_mux_net_transmit_pending = false;

	ipc_mux->tx_transaction_id = 0;

	ipc_mux->rr_next_session = 0;

	ipc_mux->event = MUX_E_INACTIVE;

	ipc_mux->channel_id = -1;

	ipc_mux->channel = NULL;

	/* Allocate the list of UL ADB. */

	for (i = 0; i < ul_tds; i++) {

		dma_addr_t mapping;

		skb = ipc_pcie_alloc_skb(ipc_mux->pcie, ul_td_size, GFP_ATOMIC,

					 &mapping, DMA_TO_DEVICE, 0);

		if (!skb) {

			ipc_mux_deinit(ipc_mux);

			return NULL;

		}

		/* Extend the UL ADB list. */

		skb_queue_tail(free_list, skb);

	}

	return ipc_mux;

}

/* Informs the network stack to restart transmission for all opened session if

 * Flow Control is not ON for that session.

 */

static void ipc_mux_restart_tx_for_all_sessions(struct iosm_mux *ipc_mux)

{

	struct mux_session *session;

	int idx;

	for (idx = 0; idx < ipc_mux->nr_sessions; idx++) {

		session = &ipc_mux->session[idx];

		if (!session->wwan)

			continue;

		/* If flow control of the session is OFF and if there was tx

		 * stop then restart. Inform the network interface to restart

		 * sending data.

		 */

		if (session->flow_ctl_mask == 0) {

			session->net_tx_stop = false;

			ipc_mux_netif_tx_flowctrl(session, idx, false);

		}

	}

}

/* Informs the network stack to stop sending further pkt for all opened

 * sessions

 */

static void ipc_mux_stop_netif_for_all_sessions(struct iosm_mux *ipc_mux)

{

	struct mux_session *session;

	int idx;

	for (idx = 0; idx < ipc_mux->nr_sessions; idx++) {

		session = &ipc_mux->session[idx];

		if (!session->wwan)

			continue;

		ipc_mux_netif_tx_flowctrl(session, session->if_id, true);

	}

}

void ipc_mux_check_n_restart_tx(struct iosm_mux *ipc_mux)

{

	if (ipc_mux->ul_flow == MUX_UL) {

		int low_thresh = IPC_MEM_MUX_UL_FLOWCTRL_LOW_B;

		if (ipc_mux->ul_data_pend_bytes < low_thresh)

			ipc_mux_restart_tx_for_all_sessions(ipc_mux);

	}

}

int ipc_mux_get_max_sessions(struct iosm_mux *ipc_mux)

{

	return ipc_mux ? ipc_mux->nr_sessions : -EFAULT;

}

enum ipc_mux_protocol ipc_mux_get_active_protocol(struct iosm_mux *ipc_mux)

{

	return ipc_mux ? ipc_mux->protocol : MUX_UNKNOWN;

}

int ipc_mux_open_session(struct iosm_mux *ipc_mux, int session_nr)

{

	struct mux_session_open *session_open;

	union mux_msg mux_msg;

	session_open = &mux_msg.session_open;

	session_open->event = MUX_E_MUX_SESSION_OPEN;

	session_open->if_id = cpu_to_le32(session_nr);

	ipc_mux->session[session_nr].flags |= IPC_MEM_WWAN_MUX;

	return ipc_mux_schedule(ipc_mux, &mux_msg);

}

int ipc_mux_close_session(struct iosm_mux *ipc_mux, int session_nr)

{

	struct mux_session_close *session_close;

	union mux_msg mux_msg;

	int ret_val;

	session_close = &mux_msg.session_close;

	session_close->event = MUX_E_MUX_SESSION_CLOSE;

	session_close->if_id = cpu_to_le32(session_nr);

	ret_val = ipc_mux_schedule(ipc_mux, &mux_msg);

	ipc_mux->session[session_nr].flags &= ~IPC_MEM_WWAN_MUX;

	return ret_val;

}

void ipc_mux_deinit(struct iosm_mux *ipc_mux)

{

	struct mux_channel_close *channel_close;

	struct sk_buff_head *free_list;

	union mux_msg mux_msg;

	struct sk_buff *skb;

	if (!ipc_mux->initialized)

		return;

	ipc_mux_stop_netif_for_all_sessions(ipc_mux);

	channel_close = &mux_msg.channel_close;

	channel_close->event = MUX_E_MUX_CHANNEL_CLOSE;

	ipc_mux_schedule(ipc_mux, &mux_msg);

	/* Empty the ADB free list. */

	free_list = &ipc_mux->ul_adb.free_list;

	/* Remove from the head of the downlink queue. */

	while ((skb = skb_dequeue(free_list)))

		ipc_pcie_kfree_skb(ipc_mux->pcie, skb);

	if (ipc_mux->channel) {

		ipc_mux->channel->ul_pipe.is_open = false;

		ipc_mux->channel->dl_pipe.is_open = false;

	}

	kfree(ipc_mux);

}

/* 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);

/**