Commit | Line | Data |
---|---|---|
f301bba0 PH |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * For transports using message passing. | |
4 | * | |
5 | * Derived from shm.c. | |
6 | * | |
7 | * Copyright (C) 2019-2021 ARM Ltd. | |
8 | * Copyright (C) 2020-2021 OpenSynergy GmbH | |
9 | */ | |
10 | ||
11 | #include <linux/types.h> | |
12 | ||
13 | #include "common.h" | |
14 | ||
15 | /* | |
16 | * struct scmi_msg_payld - Transport SDU layout | |
17 | * | |
18 | * The SCMI specification requires all parameters, message headers, return | |
19 | * arguments or any protocol data to be expressed in little endian format only. | |
20 | */ | |
21 | struct scmi_msg_payld { | |
22 | __le32 msg_header; | |
23 | __le32 msg_payload[]; | |
24 | }; | |
25 | ||
26 | /** | |
27 | * msg_command_size() - Actual size of transport SDU for command. | |
28 | * | |
29 | * @xfer: message which core has prepared for sending | |
30 | * | |
31 | * Return: transport SDU size. | |
32 | */ | |
33 | size_t msg_command_size(struct scmi_xfer *xfer) | |
34 | { | |
35 | return sizeof(struct scmi_msg_payld) + xfer->tx.len; | |
36 | } | |
37 | ||
38 | /** | |
39 | * msg_response_size() - Maximum size of transport SDU for response. | |
40 | * | |
41 | * @xfer: message which core has prepared for sending | |
42 | * | |
43 | * Return: transport SDU size. | |
44 | */ | |
45 | size_t msg_response_size(struct scmi_xfer *xfer) | |
46 | { | |
47 | return sizeof(struct scmi_msg_payld) + sizeof(__le32) + xfer->rx.len; | |
48 | } | |
49 | ||
50 | /** | |
51 | * msg_tx_prepare() - Set up transport SDU for command. | |
52 | * | |
53 | * @msg: transport SDU for command | |
54 | * @xfer: message which is being sent | |
55 | */ | |
56 | void msg_tx_prepare(struct scmi_msg_payld *msg, struct scmi_xfer *xfer) | |
57 | { | |
58 | msg->msg_header = cpu_to_le32(pack_scmi_header(&xfer->hdr)); | |
59 | if (xfer->tx.buf) | |
60 | memcpy(msg->msg_payload, xfer->tx.buf, xfer->tx.len); | |
61 | } | |
62 | ||
63 | /** | |
64 | * msg_read_header() - Read SCMI header from transport SDU. | |
65 | * | |
66 | * @msg: transport SDU | |
67 | * | |
68 | * Return: SCMI header | |
69 | */ | |
70 | u32 msg_read_header(struct scmi_msg_payld *msg) | |
71 | { | |
72 | return le32_to_cpu(msg->msg_header); | |
73 | } | |
74 | ||
75 | /** | |
76 | * msg_fetch_response() - Fetch response SCMI payload from transport SDU. | |
77 | * | |
78 | * @msg: transport SDU with response | |
79 | * @len: transport SDU size | |
80 | * @xfer: message being responded to | |
81 | */ | |
82 | void msg_fetch_response(struct scmi_msg_payld *msg, size_t len, | |
83 | struct scmi_xfer *xfer) | |
84 | { | |
85 | size_t prefix_len = sizeof(*msg) + sizeof(msg->msg_payload[0]); | |
86 | ||
87 | xfer->hdr.status = le32_to_cpu(msg->msg_payload[0]); | |
88 | xfer->rx.len = min_t(size_t, xfer->rx.len, | |
89 | len >= prefix_len ? len - prefix_len : 0); | |
90 | ||
91 | /* Take a copy to the rx buffer.. */ | |
92 | memcpy(xfer->rx.buf, &msg->msg_payload[1], xfer->rx.len); | |
93 | } | |
94 | ||
95 | /** | |
96 | * msg_fetch_notification() - Fetch notification payload from transport SDU. | |
97 | * | |
98 | * @msg: transport SDU with notification | |
99 | * @len: transport SDU size | |
100 | * @max_len: maximum SCMI payload size to fetch | |
101 | * @xfer: notification message | |
102 | */ | |
103 | void msg_fetch_notification(struct scmi_msg_payld *msg, size_t len, | |
104 | size_t max_len, struct scmi_xfer *xfer) | |
105 | { | |
106 | xfer->rx.len = min_t(size_t, max_len, | |
107 | len >= sizeof(*msg) ? len - sizeof(*msg) : 0); | |
108 | ||
109 | /* Take a copy to the rx buffer.. */ | |
110 | memcpy(xfer->rx.buf, msg->msg_payload, xfer->rx.len); | |
111 | } |