nvme: mi: dev: Implement PCIe / Configuration {Read,Write}

Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>

Author: amboar

src/lib.rs

@@ -16,6 +16,7 @@ use nvme::{
 use uuid::Uuid;
 
 pub mod nvme;
+mod pcie;
 mod wire;
 
 extern crate deku;

src/nvme/mi.rs

@@ -84,6 +84,7 @@ pub enum ResponseStatus {
     InvalidParameter = 0x04,
     InvalidCommandSize = 0x05,
     InvalidCommandInputDataSize = 0x06,
+    AccessDenied = 0x07,
 }
 unsafe impl Discriminant<u8> for ResponseStatus {}
 
@@ -908,3 +909,40 @@ struct AdminCommandResponseHeader {
     cqedw3: u32,
 }
 impl Encode<16> for AdminCommandResponseHeader {}
+
+// MI v2.0, 7, Figure 146
+#[derive(Debug, DekuRead, DekuWrite)]
+#[deku(endian = "little")]
+struct PcieCommandRequestHeader {
+    _opcode: u8,
+    #[deku(seek_from_current = "1")]
+    ctlid: u16,
+    #[deku(ctx = "*_opcode")]
+    op: PcieCommandRequestType,
+}
+
+// MI v2.0, 7, Figure 148
+#[derive(Debug, DekuRead, DekuWrite, Eq, PartialEq)]
+#[deku(ctx = "endian: Endian, opcode: u8", id = "opcode", endian = "endian")]
+#[repr(u8)]
+enum PcieCommandRequestType {
+    #[deku(id = 0x00)]
+    ConfigurationRead(PcieConfigurationAccessRequest),
+    #[deku(id = 0x01)]
+    ConfigurationWrite(PcieConfigurationAccessRequest),
+    MemoryRead = 0x02,
+    MemoryWrite = 0x03,
+    IoRead = 0x04,
+    IoWrite = 0x05,
+}
+unsafe impl Discriminant<u8> for PcieCommandRequestType {}
+
+// MI v2.0, 7, Figure 151-152
+#[derive(Debug, DekuRead, DekuWrite, Eq, PartialEq)]
+#[deku(ctx = "endian: Endian", endian = "endian")]
+struct PcieConfigurationAccessRequest {
+    length: u16,
+    #[deku(seek_from_current = "2")]
+    #[deku(pad_bytes_after = "6")]
+    offset: u16,
+}

src/nvme/mi/dev.rs

@@ -32,10 +32,11 @@ use crate::{
             ControllerPropertyFlags, MessageType, NvmSubsystemHealthDataStructureResponse,
             NvmSubsystemInformationResponse, NvmeManagementResponse, NvmeMiCommandRequestHeader,
             NvmeMiCommandRequestType, NvmeMiDataStructureManagementResponse,
-            NvmeMiDataStructureRequestType, PciePortDataResponse, PortInformationResponse,
-            TwoWirePortDataResponse,
+            NvmeMiDataStructureRequestType, PcieCommandRequestHeader, PciePortDataResponse,
+            PortInformationResponse, TwoWirePortDataResponse,
         },
     },
+    pcie::PciDeviceFunctionConfigurationSpace,
     wire::{WireString, WireVec},
 };
 
@@ -121,6 +122,18 @@ impl RequestHandler for MessageHeader {
                     }
                 }
             }
+            MessageType::PcieCommand => {
+                match &PcieCommandRequestHeader::from_bytes((rest, 0)) {
+                    Ok(((rest, _), ch)) => ch.handle(ch, mep, subsys, rest, resp, app).await,
+                    Err(err) => {
+                        debug!(
+                            "Unable to parse PcieCommandRequestHeader from message buffer: {err:?}"
+                        );
+                        // TODO: This is a bad assumption: Can see DekuError::InvalidParam too
+                        Err(ResponseStatus::InvalidCommandSize)
+                    }
+                }
+            }
             _ => {
                 debug!("Unimplemented NMINT: {:?}", ctx.nmimt());
                 Err(ResponseStatus::InternalError)
@@ -2003,6 +2016,82 @@ impl RequestHandler for AdminFormatNvmRequest {
     }
 }
 
+impl RequestHandler for PcieCommandRequestHeader {
+    type Ctx = PcieCommandRequestHeader;
+
+    async fn handle<A, C>(
+        &self,
+        ctx: &Self::Ctx,
+        _mep: &mut crate::ManagementEndpoint,
+        subsys: &mut crate::Subsystem,
+        rest: &[u8],
+        resp: &mut C,
+        _app: A,
+    ) -> Result<(), ResponseStatus>
+    where
+        A: AsyncFnMut(crate::CommandEffect) -> Result<(), CommandEffectError>,
+        C: mctp::AsyncRespChannel,
+    {
+        match &ctx.op {
+            super::PcieCommandRequestType::ConfigurationRead(req) => {
+                if !rest.is_empty() {
+                    debug!("Invalid request size for PcieCommand");
+                    return Err(ResponseStatus::InvalidCommandSize);
+                }
+
+                if req.length != 4096 {
+                    debug!("Implement length support");
+                    return Err(ResponseStatus::InternalError);
+                }
+
+                if req.offset != 0 {
+                    debug!("Implement offset support");
+                    return Err(ResponseStatus::InternalError);
+                }
+
+                let mh = MessageHeader::respond(MessageType::PcieCommand).encode()?;
+
+                let status = [0u8; 4]; /* Success */
+
+                let cr = PciDeviceFunctionConfigurationSpace::builder()
+                    .vid(subsys.info.pci_vid)
+                    .did(subsys.info.pci_did)
+                    .svid(subsys.info.pci_svid)
+                    .sdid(subsys.info.pci_sdid)
+                    .build()
+                    .encode()?;
+
+                send_response(resp, &[&mh.0, &status, &cr.0]).await;
+                Ok(())
+            }
+            super::PcieCommandRequestType::ConfigurationWrite(req) => {
+                let response = if rest.len() == req.length as usize {
+                    debug!("Unsupported write at {} for {}", req.offset, req.length);
+                    ResponseStatus::AccessDenied
+                } else {
+                    debug!(
+                        "Request data size {} does not match requested write size {}",
+                        rest.len(),
+                        req.length
+                    );
+                    ResponseStatus::InvalidCommandInputDataSize
+                };
+
+                let mh = MessageHeader::respond(MessageType::PcieCommand).encode()?;
+
+                let status = [response.id(), 0, 0, 0];
+
+                send_response(resp, &[&mh.0, &status]).await;
+                Ok(())
+            }
+            _ => {
+                debug!("Unimplemented OPCODE: {:?}", ctx._opcode);
+                Err(ResponseStatus::InternalError)
+            }
+        }
+    }
+}
+
 impl crate::ManagementEndpoint {
     fn update(&mut self, subsys: &crate::Subsystem) {
         assert!(subsys.ctlrs.len() <= self.mecss.len());

src/pcie.rs

@@ -0,0 +1,216 @@
+// SPDX-License-Identifier: GPL-3.0-only
+/*
+ * Copyright (c) 2025 Code Construct
+ */
+use deku::ctx::Endian;
+use deku::{DekuRead, DekuWrite};
+
+// PCIe Base 4.0r1.0, 7.5.1.2, Figure 7-10
+#[derive(Debug, DekuRead, DekuWrite)]
+#[deku(endian = "little")]
+pub struct PciDeviceFunctionConfigurationSpace {
+    vid: u16,
+    did: u16,
+    cmd: u16,
+    sts: u16,
+    rid: u8,
+    #[deku(bytes = "3")]
+    cc: u32,
+    cls: u8,
+    lt: u8,
+    ht: u8,
+    bist: u8,
+    bars: [u32; 6],
+    cis: u32,
+    svid: u16,
+    sdid: u16,
+    rom: u32,
+    cap: u8,
+    #[deku(seek_from_current = "7")]
+    il: u8,
+    ip: u8,
+    min_gnt: u8,
+    max_lat: u8,
+    caps: [PciCapabilityType; 2],
+}
+impl crate::Encode<4096> for PciDeviceFunctionConfigurationSpace {}
+
+impl PciDeviceFunctionConfigurationSpace {
+    pub fn new() -> Self {
+        Self {
+            vid: 0xffff,
+            did: 0xffff,
+            cmd: 0,
+            sts: 0x0010,
+            rid: 0,
+            cc: 0x010803,
+            cls: 0,
+            lt: 0,
+            ht: 0,
+            bist: 0,
+            bars: [0; 6],
+            cis: 0,
+            svid: 0xffff,
+            sdid: 0xffff,
+            rom: 0,
+            cap: 0x40,
+            il: 0,
+            ip: 0,
+            min_gnt: 0,
+            max_lat: 0,
+            caps: [
+                PciCapabilityType::PciPowerManagement(PciPowerManagementCapability {
+                    next: 0x48,
+                    pmc: {
+                        PowerManagementCapabilities {
+                            version: 3,
+                            pme_clock: false,
+                            ready_d0: true,
+                            dsi: false,
+                            aux_current: 0,
+                            d1: false,
+                            d2: false,
+                            pme: 0,
+                        }
+                    }
+                    .into(),
+                    pmcsr: 0,
+                    data: 0,
+                }),
+                PciCapabilityType::Pcie(PcieCapability::default()),
+            ],
+        }
+    }
+
+    pub fn builder() -> PciDeviceFunctionConfigurationSpaceBuilder {
+        Default::default()
+    }
+}
+
+impl Default for PciDeviceFunctionConfigurationSpace {
+    fn default() -> Self {
+        PciDeviceFunctionConfigurationSpace::new()
+    }
+}
+
+pub struct PciDeviceFunctionConfigurationSpaceBuilder {
+    vid: u16,
+    did: u16,
+    svid: u16,
+    sdid: u16,
+}
+
+impl Default for PciDeviceFunctionConfigurationSpaceBuilder {
+    fn default() -> Self {
+        Self {
+            vid: 0xffff,
+            did: 0xffff,
+            svid: 0xffff,
+            sdid: 0xffff,
+        }
+    }
+}
+
+impl PciDeviceFunctionConfigurationSpaceBuilder {
+    pub fn vid(&mut self, vid: u16) -> &mut Self {
+        self.vid = vid;
+        self
+    }
+
+    pub fn did(&mut self, did: u16) -> &mut Self {
+        self.did = did;
+        self
+    }
+
+    pub fn svid(&mut self, svid: u16) -> &mut Self {
+        self.svid = svid;
+        self
+    }
+
+    pub fn sdid(&mut self, sdid: u16) -> &mut Self {
+        self.sdid = sdid;
+        self
+    }
+
+    pub fn build(&self) -> PciDeviceFunctionConfigurationSpace {
+        PciDeviceFunctionConfigurationSpace {
+            vid: self.vid,
+            did: self.did,
+            svid: self.svid,
+            sdid: self.sdid,
+            ..Default::default()
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct PowerManagementCapabilities {
+    version: u8,
+    pme_clock: bool,
+    ready_d0: bool,
+    dsi: bool,
+    aux_current: u8,
+    d1: bool,
+    d2: bool,
+    pme: u8,
+}
+
+impl From<PowerManagementCapabilities> for u16 {
+    fn from(value: PowerManagementCapabilities) -> Self {
+        ((value.pme as u16 & 0xf) << 11)
+            | ((value.d2 as u16) << 10)
+            | ((value.d1 as u16) << 9)
+            | ((value.aux_current as u16 & 0x7) << 6)
+            | ((value.dsi as u16) << 5)
+            | ((value.ready_d0 as u16) << 4)
+            | ((value.pme_clock as u16) << 3)
+            | (value.version as u16 & 0x7)
+    }
+}
+
+#[derive(Debug, DekuRead, DekuWrite)]
+#[deku(ctx = "endian: Endian", endian = "endian")]
+pub struct PciPowerManagementCapability {
+    next: u8,
+    pmc: u16,
+    pmcsr: u16,
+    #[deku(seek_from_current = "1")]
+    data: u8,
+}
+
+#[derive(Debug, Default, DekuRead, DekuWrite)]
+#[deku(ctx = "endian: Endian", endian = "endian")]
+pub struct PcieCapability {
+    next: u8,
+    pciec: u16,
+    devcap: u32,
+    devctl: u16,
+    devsts: u16,
+    linkcap: u32,
+    linkctl: u16,
+    linksts: u16,
+    slotctl: u16,
+    slotsts: u16,
+    rootctl: u16,
+    rootsts: u16,
+    devcap2: u32,
+    devctl2: u16,
+    devsts2: u16,
+    linkcap2: u32,
+    linkctl2: u16,
+    linksts2: u16,
+    slotcap2: u32,
+    slotctl2: u16,
+    slotsts2: u16,
+}
+
+#[derive(Debug, DekuRead, DekuWrite)]
+#[deku(ctx = "endian: Endian", endian = "endian", id_type = "u8")]
+#[repr(u8)]
+pub enum PciCapabilityType {
+    #[deku(id = "0x01")]
+    PciPowerManagement(PciPowerManagementCapability),
+    #[deku(id = "0x10")]
+    Pcie(PcieCapability),
+}
+unsafe impl crate::Discriminant<u8> for PciCapabilityType {}