// SPDX-License-Identifier: GPL-2.0/* * For transports using message passing. * * Derived from shm.c. * * Copyright (C) 2019-2024 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 {	__le32 msg_header;	__le32 msg_payload[];}; /** * msg_command_size() - Actual size of transport SDU for command. * * @xfer: message which core has prepared for sending * * Return: transport SDU size. */static size_t msg_command_size(struct scmi_xfer *xfer){	return sizeof(struct scmi_msg_payld) + xfer->tx.len;} /** * msg_response_size() - Maximum size of transport SDU for response. * * @xfer: message which core has prepared for sending * * Return: transport SDU size. */static size_t msg_response_size(struct scmi_xfer *xfer){	return sizeof(struct scmi_msg_payld) + sizeof(__le32) + xfer->rx.len;} /** * msg_tx_prepare() - Set up transport SDU for command. * * @msg: transport SDU for command * @xfer: message which is being sent */static void msg_tx_prepare(struct scmi_msg_payld *msg, struct scmi_xfer *xfer){	msg->msg_header = cpu_to_le32(pack_scmi_header(&xfer->hdr));	if (xfer->tx.buf)		memcpy(msg->msg_payload, xfer->tx.buf, xfer->tx.len);} /** * msg_read_header() - Read SCMI header from transport SDU. * * @msg: transport SDU * * Return: SCMI header */static u32 msg_read_header(struct scmi_msg_payld *msg){	return le32_to_cpu(msg->msg_header);} /** * msg_fetch_response() - Fetch response SCMI payload from transport SDU. * * @msg: transport SDU with response * @len: transport SDU size * @xfer: message being responded to */static void msg_fetch_response(struct scmi_msg_payld *msg,			       size_t len, struct scmi_xfer *xfer){	size_t prefix_len = sizeof(*msg) + sizeof(msg->msg_payload[0]); 	xfer->hdr.status = le32_to_cpu(msg->msg_payload[0]);	xfer->rx.len = min_t(size_t, xfer->rx.len,			     len >= prefix_len ? len - prefix_len : 0); 	/* Take a copy to the rx buffer.. */	memcpy(xfer->rx.buf, &msg->msg_payload[1], xfer->rx.len);} /** * 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 */static void msg_fetch_notification(struct scmi_msg_payld *msg, size_t len,				   size_t max_len, struct scmi_xfer *xfer){	xfer->rx.len = min_t(size_t, max_len,			     len >= sizeof(*msg) ? len - sizeof(*msg) : 0); 	/* Take a copy to the rx buffer.. */	memcpy(xfer->rx.buf, msg->msg_payload, xfer->rx.len);} static const struct scmi_message_operations scmi_msg_ops = {	.tx_prepare = msg_tx_prepare,	.command_size = msg_command_size,	.response_size = msg_response_size,	.read_header = msg_read_header,	.fetch_response = msg_fetch_response,	.fetch_notification = msg_fetch_notification,}; const struct scmi_message_operations *scmi_message_operations_get(void){	return &scmi_msg_ops;}