linux/drivers/firmware/arm_scmi/msg.c

// SPDX-License-Identifier: GPL-2.0
/*
 * For transports using message passing.
 *
 * Derived from shm.c.
 *
 * Copyright (C) 2019-2021 ARM Ltd.
 * Copyright (C) 2020-2021 OpenSynergy GmbH
 */

#include <linux/types.h>

#include "common.h"

/*
 * struct scmi_msg_payld - Transport SDU layout
 *
 * The SCMI specification requires all parameters, message headers, return
 * arguments or any protocol data to be expressed in little endian format only.
 */
struct scmi_msg_payld { … };

/**
 * msg_command_size() - Actual size of transport SDU for command.
 *
 * @xfer: message which core has prepared for sending
 *
 * Return: transport SDU size.
 */
size_t msg_command_size(struct scmi_xfer *xfer)
{ … }

/**
 * msg_response_size() - Maximum size of transport SDU for response.
 *
 * @xfer: message which core has prepared for sending
 *
 * Return: transport SDU size.
 */
size_t msg_response_size(struct scmi_xfer *xfer)
{ … }

/**
 * msg_tx_prepare() - Set up transport SDU for command.
 *
 * @msg: transport SDU for command
 * @xfer: message which is being sent
 */
void msg_tx_prepare(struct scmi_msg_payld *msg, struct scmi_xfer *xfer)
{ … }

/**
 * msg_read_header() - Read SCMI header from transport SDU.
 *
 * @msg: transport SDU
 *
 * Return: SCMI header
 */
u32 msg_read_header(struct scmi_msg_payld *msg)
{ … }

/**
 * msg_fetch_response() - Fetch response SCMI payload from transport SDU.
 *
 * @msg: transport SDU with response
 * @len: transport SDU size
 * @xfer: message being responded to
 */
void msg_fetch_response(struct scmi_msg_payld *msg, size_t len,
			struct scmi_xfer *xfer)
{ … }

/**
 * msg_fetch_notification() - Fetch notification payload from transport SDU.
 *
 * @msg: transport SDU with notification
 * @len: transport SDU size
 * @max_len: maximum SCMI payload size to fetch
 * @xfer: notification message
 */
void msg_fetch_notification(struct scmi_msg_payld *msg, size_t len,
			    size_t max_len, struct scmi_xfer *xfer)
{ … }