projects/linux·blob master · refs

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1// SPDX-License-Identifier: GPL-2.0
2// SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
3
4//! MCTP/NVDM protocol types for NVIDIA GPU firmware communication.
5//!
6//! MCTP (Management Component Transport Protocol) carries NVDM (NVIDIA
7//! Data Model) messages between the kernel driver and GPU firmware processors
8//! such as FSP and GSP.
9
10use kernel::{
11 bitfield,
12 pci::Vendor,
13 prelude::*, //
14};
15
16use crate::{
17 bounded_enum,
18 num, //
19};
20
21bounded_enum! {
22 /// NVDM message type identifiers carried over MCTP.
23 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
24 pub(crate) enum NvdmType with TryFrom<Bounded<u32, 8>> {
25 /// PRC (Product Reconfiguration Control) message.
26 Prc = 0x13,
27 /// Chain of Trust boot message.
28 Cot = 0x14,
29 /// FSP command response.
30 FspResponse = 0x15,
31 }
32}
33
34bitfield! {
35 /// MCTP transport header for NVIDIA firmware messages.
36 pub(crate) struct MctpHeader(u32) {
37 /// Start-of-message bit.
38 31:31 som;
39 /// End-of-message bit.
40 30:30 eom;
41 /// Packet sequence number.
42 29:28 seq;
43 /// Source endpoint ID.
44 23:16 seid;
45 }
46}
47
48impl MctpHeader {
49 /// Builds a single-packet MCTP header (`SOM=1`, `EOM=1`, `SEQ=0`, `SEID=0`).
50 pub(crate) fn single_packet() -> Self {
51 Self::zeroed().with_som(true).with_eom(true)
52 }
53
54 /// Returns whether this is a complete single-packet message (`SOM=1` and `EOM=1`).
55 pub(crate) fn is_single_packet(self) -> bool {
56 self.som().into_bool() && self.eom().into_bool()
57 }
58}
59
60/// MCTP message type for PCI vendor-defined messages.
61const MSG_TYPE_VENDOR_PCI: u8 = 0x7e;
62
63bitfield! {
64 /// NVIDIA Vendor-Defined Message header over MCTP.
65 pub(crate) struct NvdmHeader(u32) {
66 /// NVDM message type.
67 31:24 nvdm_type ?=> NvdmType;
68 /// PCI vendor ID.
69 23:8 vendor_id;
70 /// MCTP vendor-defined message type.
71 6:0 msg_type;
72 }
73}
74
75impl NvdmHeader {
76 /// Builds an NVDM header for the given message type.
77 pub(crate) fn new(nvdm_type: NvdmType) -> Self {
78 Self::zeroed()
79 .with_const_msg_type::<{ num::u8_as_u32(MSG_TYPE_VENDOR_PCI) }>()
80 .with_vendor_id(Vendor::NVIDIA.as_raw())
81 .with_nvdm_type(nvdm_type)
82 }
83
84 /// Validates this header against the expected NVIDIA NVDM format and type.
85 pub(crate) fn validate(self, expected_type: NvdmType) -> bool {
86 u8::from(self.msg_type()) == MSG_TYPE_VENDOR_PCI
87 && u16::from(self.vendor_id()) == Vendor::NVIDIA.as_raw()
88 && matches!(self.nvdm_type(), Ok(nvdm_type) if nvdm_type == expected_type)
89 }
90}