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 10 use kernel::{ 11 bitfield, 12 pci::Vendor, 13 prelude::*, // 14 }; 15 16 use crate::{ 17 bounded_enum, 18 num, // 19 }; 20 21 bounded_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 34 bitfield! { 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 48 impl 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. 61 const MSG_TYPE_VENDOR_PCI: u8 = 0x7e; 62 63 bitfield! { 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 75 impl 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 } 91