linux/drivers/firmware/arm_scmi/msg.c
Cristian Marussi fc789363c9 firmware: arm_scmi: Remove legacy transport-layer code
Since all SCMI transports have been made standalone drivers, remove all the
core SCMI stack legacy support that was needed to run transports as built
into the stack.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
Message-Id: <20240812173340.3912830-10-cristian.marussi@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
2024-08-16 10:26:58 +01:00

126 lines
3.2 KiB
C

// 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;
}