Rust XHCI Register Types.

rust/Cargo.lock

@@ -193,6 +193,7 @@ dependencies = [
 name = "voyageurs"
 version = "0.1.0"
 dependencies = [
+ "bitfield-struct",
  "mammoth",
 ]
 

rust/sys/voyageurs/Cargo.toml

@@ -4,4 +4,5 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+bitfield-struct = "0.8.0"
 mammoth = { path = "../../lib/mammoth/" }

rust/sys/voyageurs/src/main.rs

@@ -3,6 +3,8 @@
 
 extern crate alloc;
 
+mod xhci;
+
 use mammoth::{debug, define_entry, zion::z_err_t};
 
 define_entry!();

rust/sys/voyageurs/src/xhci/mod.rs

@@ -0,0 +1 @@
+pub mod registers;

rust/sys/voyageurs/src/xhci/registers/capabilities.rs

@@ -0,0 +1,344 @@
+use bitfield_struct::bitfield;
+
+#[bitfield(u32)]
+pub struct HostControllerCapabilitiesLengthAndVersion {
+    /// This register is used as an offset to add to register base to find the beginning of
+    /// the Operational Register Space.
+    #[bits(access=RO)]
+    pub cap_length: u8,
+    __: u8,
+    /// This is a two-byte register containing a BCD encoding of the xHCI specification
+    /// revision number supported by this host controller. The most significant byte of
+    /// this register represents a major revision and the least significant byte contains
+    /// the minor revision extensions. e.g. 0100h corresponds to xHCI version 1.0.0, or
+    /// 0110h corresponds to xHCI version 1.1.0, etc
+    #[bits(access=RO)]
+    pub hci_version: u16,
+}
+
+#[bitfield(u32)]
+pub struct HCSParams1 {
+    /// Number of Device Slots (MaxSlots). This field specifies the maximum number of Device
+    /// Context Structures and Doorbell Array entries this host controller can support. Valid values are
+    /// in the range of 1 to 255. The value of ‘0’ is reserved.
+    #[bits(access=RO)]
+    pub max_device_slots: u8,
+
+    /// Number of Interrupters (MaxIntrs). This field specifies the number of Interrupters implemented
+    /// on this host controller. Each Interrupter may be allocated to a MSI or MSI-X vector and controls
+    /// its generation and moderation.
+    ///
+    /// The value of this field determines how many Interrupter Register Sets are addressable in the
+    /// Runtime Register Space (refer to section 5.5). Valid values are in the range of 1h to 400h. A ‘0’ in
+    /// this field is undefined.
+    #[bits(11, access=RO)]
+    pub max_interrupters: u16,
+
+    #[bits(5)]
+    __: u8,
+    /// Number of Ports (MaxPorts). This field specifies the maximum Port Number value, i.e. the
+    /// highest numbered Port Register Set that are addressable in the Operational Register Space
+    /// (refer to Table 5-18). Valid values are in the range of 1h to FFh.
+    ///
+    /// The value in this field shall reflect the maximum Port Number value assigned by an xHCI
+    /// Supported Protocol Capability, described in section 7.2. Software shall refer to these capabilities
+    /// to identify whether a specific Port Number is valid, and the protocol supported by the
+    /// associated Port Register Set.
+    #[bits(access=RO)]
+    pub max_ports: u8,
+}
+
+#[bitfield(u32)]
+pub struct HCSParams2 {
+    /// Isochronous Scheduling Threshold (IST). Default = implementation dependent. The value in
+    /// this field indicates to system software the minimum distance (in time) that it is required to stay
+    /// ahead of the host controller while adding TRBs, in order to have the host controller process
+    /// them at the correct time. The value shall be specified in terms of number of
+    /// frames/microframes.
+    ///
+    /// If bit [3] of IST is cleared to '0', software can add a TRB no later than IST[2:0] Microframes
+    /// before that TRB is scheduled to be executed.
+    ///
+    /// If bit [3] of IST is set to '1', software can add a TRB no later than IST[2:0] Frames before that TRB
+    /// is scheduled to be executed.
+    ///
+    /// Refer to Section 4.14.2 for details on how software uses this information for scheduling
+    /// isochronous transfers.
+    #[bits(4, access=RO)]
+    pub isochronous_scheduling_threshold: u8,
+    /// Event Ring Segment Table Max (ERST Max). Default = implementation dependent. Valid values
+    /// are 0 – 15. This field determines the maximum value supported the Event Ring Segment Table
+    /// Base Size registers (5.5.2.3.1), where:
+    ///
+    /// The maximum number of Event Ring Segment Table entries = 2 ERST Max.
+    /// e.g. if the ERST Max = 7, then the xHC Event Ring Segment Table(s) supports up to 128 entries,
+    /// 15 then 32K entries, etc.
+    #[bits(4, access=RO)]
+    pub event_ring_segment_table_max: u8,
+
+    #[bits(13)]
+    __: u16,
+
+    /// Max Scratchpad Buffers (Max Scratchpad Bufs Hi). Default = implementation dependent. This
+    /// field indicates the high order 5 bits of the number of Scratchpad Buffers system software shall
+    /// reserve for the xHC. Refer to section 4.20 for more information.
+    #[bits(5, access=RO)]
+    max_scratchpad_buffers_hi: u16,
+
+    /// Scratchpad Restore (SPR). Default = implementation dependent. If Max Scratchpad Buffers is >
+    /// ‘0’ then this flag indicates whether the xHC uses the Scratchpad Buffers for saving state when
+    /// executing Save and Restore State operations. If Max Scratchpad Buffers is = ‘0’ then this flag
+    /// shall be ‘0’. Refer to section 4.23.2 for more information.
+    ///
+    /// A value of ‘1’ indicates that the xHC requires the integrity of the Scratchpad Buffer space to be
+    /// maintained across power events.
+    ///
+    /// A value of ‘0’ indicates that the Scratchpad Buffer space may be freed and reallocated between
+    /// power events.
+    #[bits(access=RO)]
+    pub scratchpad_restore: bool,
+
+    /// Max Scratchpad Buffers (Max Scratchpad Bufs Lo). Default = implementation dependent. Valid
+    /// values for Max Scratchpad Buffers (Hi and Lo) are 0-1023. This field indicates the low order 5
+    /// bits of the number of Scratchpad Buffers system software shall reserve for the xHC. Refer to
+    /// section 4.20 for more information
+    #[bits(5, access=RO)]
+    max_scratchpad_buffers_lo: u16,
+}
+
+impl HCSParams2 {
+    pub fn max_scratchpad_buffers(&self) -> u16 {
+        (self.max_scratchpad_buffers_hi()) << 5 | self.max_scratchpad_buffers_lo()
+    }
+}
+
+#[bitfield(u32)]
+pub struct HCSParams3 {
+    /// U1 Device Exit Latency. Worst case latency to transition a root hub Port Link State (PLS) from
+    /// U1 to U0. Applies to all root hub ports.
+    /// The following are permissible values:
+    ///
+    /// Value Description
+    /// 00h Zero
+    /// 01h Less than 1 μs
+    /// 02h Less than 2 μs.
+    /// …
+    /// 0Ah Less than 10 μs
+    #[bits(access=RO)]
+    pub u1_device_exit_latency: u8,
+    /// U2 Device Exit Latency. Worst case latency to transition from U2 to U0. Applies to all root hub
+    /// ports.
+    /// The following are permissible values:
+    /// Value Description
+    /// 0000h Zero
+    /// 0001h Less than 1 μs.
+    /// 0002h Less than 2 μs.
+    /// …
+    /// 07FFh Less than 2047 μs.
+    /// 0800-FFFFh Reserved
+    #[bits(access=RO)]
+    pub u2_device_exit_latency: u8,
+    __: u16,
+}
+
+#[bitfield(u32)]
+pub struct HCCParams1 {
+    /// 64-bit Addressing Capability (AC64). This flag documents the addressing range capability of
+    /// this implementation. The value of this flag determines whether the xHC has implemented the
+    /// high order 32 bits of 64 bit register and data structure pointer fields. Values for this flag have the
+    /// following interpretation:
+    ///
+    /// Value Description
+    /// 0 32-bit address memory pointers implemented
+    /// 1 64-bit address memory pointers implemented
+    ///
+    /// If 32-bit address memory pointers are implemented, the xHC shall ignore the high order 32 bits
+    /// of 64 bit data structure pointer fields, and system software shall ignore the high order 32 bits of
+    /// 64 bit xHC registers.
+    #[bits(access=RO)]
+    pub supports_64_bit: bool,
+    /// BW Negotiation Capability (BNC). This flag identifies whether the xHC has implemented the
+    /// Bandwidth Negotiation. Values for this flag have the following interpretation:
+    ///
+    /// Value Description
+    /// 0 BW Negotiation not implemented
+    /// 1 BW Negotiation implemented
+    ///
+    /// Refer to section 4.16 for more information on Bandwidth Negotiation.
+    #[bits(access=RO)]
+    pub bandwidth_negotiation: bool,
+    /// Context Size (CSZ). If this bit is set to ‘1’, then the xHC uses 64 byte Context data structures. If
+    /// this bit is cleared to ‘0’, then the xHC uses 32 byte Context data structures.
+    /// Note: This flag does not apply to Stream Contexts.
+    #[bits(access=RO)]
+    pub context_size: bool,
+    /// Port Power Control (PPC). This flag indicates whether the host controller implementation
+    /// includes port power control. A ‘1’ in this bit indicates the ports have port power switches. A ‘0’ in
+    /// this bit indicates the port do not have port power switches. The value of this flag affects the
+    /// functionality of the PP flag in each port status and control register (refer to Section 5.4.8)
+    #[bits(access=RO)]
+    pub port_power_control: bool,
+    /// Port Indicators (PIND). This bit indicates whether the xHC root hub ports support port indicator
+    /// control. When this bit is a ‘1’, the port status and control registers include a read/writeable field
+    /// for controlling the state of the port indicator. Refer to Section 5.4.8 for definition of the Port
+    /// Indicator Control field.
+    #[bits(access=RO)]
+    pub port_indicators: bool,
+    /// Light HC Reset Capability (LHRC). This flag indicates whether the host controller implementation
+    /// supports a Light Host Controller Reset. A ‘1’ in this bit indicates that Light Host Controller Reset is
+    /// supported. A ‘0’ in this bit indicates that Light Host Controller Reset is not supported. The value
+    /// of this flag affects the functionality of the Light Host Controller Reset (LHCRST) flag in the
+    /// USBCMD register (refer to Section 5.4.1).
+    #[bits(access=RO)]
+    pub light_hc_reset_capability: bool,
+    /// Latency Tolerance Messaging Capability (LTC). This flag indicates whether the host controller
+    /// implementation supports Latency Tolerance Messaging (LTM). A ‘1’ in this bit indicates that LTM
+    /// is supported. A ‘0’ in this bit indicates that LTM is not supported. Refer to section 4.13.1 for more
+    /// information on LTM
+    #[bits(access=RO)]
+    pub latency_tolerance_messaging_capability: bool,
+    /// No Secondary SID Support (NSS). This flag indicates whether the host controller
+    /// implementation supports Secondary Stream IDs. A ‘1’ in this bit indicates that Secondary Stream
+    /// ID decoding is not supported. A ‘0’ in this bit indicates that Secondary Stream ID decoding is
+    /// supported. (refer to Sections 4.12.2 and 6.2.3)
+    #[bits(access=RO)]
+    pub no_secondary_sid_support: bool,
+    /// Parse All Event Data (PAE). This flag indicates whether the host controller implementation
+    /// Parses all Event Data TRBs while advancing to the next TD after a Short Packet, or it skips all but
+    /// the first Event Data TRB. A ‘1’ in this bit indicates that all Event Data TRBs are parsed. A ‘0’ in this
+    /// bit indicates that only the first Event Data TRB is parsed (refer to section 4.10.1.1).
+    #[bits(access=RO)]
+    pub parse_all_event_data: bool,
+    /// Stopped - Short Packet Capability (SPC). This flag indicates that the host controller
+    /// implementation is capable of generating a Stopped - Short Packet Completion Code. Refer to
+    /// section 4.6.9 for more information
+    #[bits(access=RO)]
+    pub stopped_short_packet_capability: bool,
+    /// Stopped EDTLA Capability (SEC). This flag indicates that the host controller implementation
+    /// Stream Context support a Stopped EDTLA field. Refer to sections 4.6.9, 4.12, and 6.4.4.1 for more
+    /// information.
+    /// Stopped EDTLA Capability support (i.e. SEC = '1') shall be mandatory for all xHCI 1.1 and xHCI 1.2
+    /// compliant xHCs.
+    #[bits(access=RO)]
+    pub stopped_edtla_capability: bool,
+    /// Contiguous Frame ID Capability (CFC). This flag indicates that the host controller
+    /// implementation is capable of matching the Frame ID of consecutive Isoch TDs. Refer to section
+    /// 4.11.2.5 for more information.
+    #[bits(access=RO)]
+    pub contiguous_frame_id_capability: bool,
+    /// Maximum Primary Stream Array Size (MaxPSASize). This fields identifies the maximum size
+    /// Primary Stream Array that the xHC supports. The Primary Stream Array size = 2MaxPSASize+1. Valid
+    /// MaxPSASize values are 0 to 15, where ‘0’ indicates that Streams are not supported
+    #[bits(4, access=RO)]
+    pub maximum_primary_stream_array_size: u8,
+    /// xHCI Extended Capabilities Pointer (xECP). This field indicates the existence of a capabilities list.
+    /// The value of this field indicates a relative offset, in 32-bit words, from Base to the beginning of
+    /// the first extended capability.
+    ///
+    /// For example, using the offset of Base is 1000h and the xECP value of 0068h, we can calculated
+    /// the following effective address of the first extended capability:
+    /// 1000h + (0068h << 2) -> 1000h + 01A0h -> 11A0h
+    #[bits(access=RO)]
+    pub xhci_extended_capabilities_pointer: u16,
+}
+
+#[bitfield(u32)]
+pub struct HCCParams2 {
+    /// U3 Entry Capability (U3C) - RO. This bit indicates whether the xHC Root Hub ports support port
+    /// Suspend Complete notification. When this bit is '1', PLC shall be asserted on any transition of
+    /// PLS to the U3 State. Refer to section 4.15.1 for more information.
+    #[bits(access=RO)]
+    pub u3_entry_capability: bool,
+    /// Configure Endpoint Command Max Exit Latency Too Large Capability (CMC) - RO. This bit
+    /// indicates whether a Configure Endpoint Command is capable of generating a Max Exit Latency
+    /// Too Large Capability Error. When this bit is '1', a Max Exit Latency Too Large Capability Error
+    /// may be returned by a Configure Endpoint Command. When this bit is '0', a Max Exit Latency Too
+    /// Large Capability Error shall not be returned by a Configure Endpoint Command. This capability
+    /// is enabled by the CME flag in the USBCMD register. Refer to sections 4.23.5.2 and 5.4.1 for more
+    /// information.
+    #[bits(access=RO)]
+    pub configure_endpoint_command_max_exit_latency_too_large_capability: bool,
+    /// Force Save Context Capability (FSC) - RO. This bit indicates whether the xHC supports the
+    /// Force Save Context Capability. When this bit is '1', the Save State operation shall save any
+    /// cached Slot, Endpoint, Stream or other Context information to memory. Refer to
+    /// Implementation Note “FSC and Context handling by Save and Restore”, and sections 4.23.2 and
+    /// 5.4.1 for more information.
+    #[bits(access=RO)]
+    pub force_save_context_capability: bool,
+    /// Compliance Transition Capability (CTC) - RO. This bit indicates whether the xHC USB3 Root
+    /// Hub ports support the Compliance Transition Enabled (CTE) flag. When this bit is ‘1’, USB3 Root
+    /// Hub port state machine transitions to the Compliance substate shall be explicitly enabled
+    /// software. When this bit is ‘0’, USB3 Root Hub port state machine transitions to the Compliance
+    /// substate are automatically enabled. Refer to section 4.19.1.2.4.1 for more information.
+    #[bits(access=RO)]
+    pub compliance_transition_capability: bool,
+    /// Large ESIT Payload Capability (LEC) - RO. This bit indicates whether the xHC supports ESIT
+    /// Payloads greater than 48K bytes. When this bit is ‘1’, ESIT Payloads greater than 48K bytes are
+    /// supported. When this bit is ‘0’, ESIT Payloads greater than 48K bytes are not supported. Refer to
+    /// section 6.2.3.8 for more information.
+    #[bits(access=RO)]
+    pub large_esit_payload_capability: bool,
+    /// Configuration Information Capability (CIC) - RO. This bit indicates if the xHC supports
+    /// extended Configuration Information. When this bit is 1, the Configuration Value, Interface
+    /// Number, and Alternate Setting fields in the Input Control Context are supported. When this bit is
+    /// 0, the extended Input Control Context fields are not supported. Refer to section 6.2.5.1 for more
+    /// information.
+    #[bits(access=RO)]
+    pub configuration_information_capability: bool,
+    /// Extended TBC Capability78 (ETC) - RO. This bit indicates if the TBC field in an Isoch TRB
+    /// supports the definition of Burst Counts greater than 65535 bytes. When this bit is ‘1’, the
+    /// Extended EBC capability is supported by the xHC. When this bit is ‘0’, it is not. Refer to section
+    /// 4.11.2.3 for more information.
+    #[bits(access=RO)]
+    pub extended_tbc_capability: bool,
+    /// Extended TBC TRB Status Capability (ETC_TSC) - RO. This bit indicates if the TBC/TRBSts field
+    /// in an Isoch TRB indicates additional information regarding TRB in the TD. When this bit is ‘1’, the
+    /// Isoch TRB TD Size/TBC field presents TBC value and TBC/TRBSts field presents the TRBSts
+    /// value. When this bit is ‘0’ then the ETC/ETE values defines the TD Size/TBC field and TBC/RsvdZ
+    /// field. This capability shall be enabled only if LEC = ‘1’ and ETC=’1’. Refer to section 4.11.2.3 for
+    /// more information.
+    #[bits(access=RO)]
+    pub extended_tbc_trb_status_capability: bool,
+    /// Get/Set Extended Property Capability (GSC) – RO. This bit indicates support for the Set
+    /// Extended Property and Get Extended Property commands. When this bit is ‘1’, the xHC supports
+    /// the Get Extended Property and Set Extended Property commands defined in section 4.6.17 and
+    /// section 4.6.18. When this bit is ‘0’, the xHC does not support the Get Extended Property and Set
+    /// Extended Property commands and the xHC does not support any of the associated Extended
+    /// Capabilities.
+    ///
+    /// This bit shall only be set to ‘1’ if the xHC supports one or more extended capabilities that
+    /// require the Get Extended Property and Set Extended Property commands.
+    #[bits(access=RO)]
+    pub get_set_extended_property_capability: bool,
+    /// Virtualization Based Trusted I/O Capability (VTC) – RO. This bit when set to 1, indicates that
+    /// the xHC supports the Virtualization based Trusted IO (VTIO) Capability. When this bit is 0, the
+    /// VTIO Capability is not supported. This capability is enabled by the VTIOE flag in the USBCMD
+    /// register.
+    #[bits(access=RO)]
+    pub virtualization_based_trusted_io_capability: bool,
+
+    #[bits(22)]
+    __: u32,
+}
+
+/// XHCI Spec Section 5.3
+/// Note that for 64 bit implementations, the controller requires qword (32bit) accesses.
+/// Hence the grouping of parameters here.
+///
+/// These registers are located at the addresses specified in BAR0 and BAR1 in the PCI Header.
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct HostControllerCapabilities {
+    pub cap_length_and_version: HostControllerCapabilitiesLengthAndVersion,
+    pub params_1: HCSParams1,
+    pub params_2: HCSParams2,
+    pub params_3: HCSParams3,
+    pub cap_params_1: HCCParams1,
+    /// This register defines the offset of the Doorbell Array base address from the Base. (RO)
+    pub doorbell_offset: u32,
+    /// This register defines the offset of the xHCI Runtime Registers from the Base.
+    pub runtime_register_space_offset: u32,
+    pub cap_params_2: HCCParams2,
+}
+
+const _: () = assert!(size_of::<HostControllerCapabilities>() == 0x20);

rust/sys/voyageurs/src/xhci/registers/doorbell.rs

@@ -0,0 +1,108 @@
+use core::ptr::NonNull;
+
+use alloc::{boxed::Box, vec::Vec};
+use bitfield_struct::bitfield;
+use volatile::VolatileRef;
+
+/// The Doorbell Array is organized as an array of up to 256 Doorbell Registers. One
+/// 32-bit Doorbell Register is defined in the array for each Device Slot. System
+/// software utilizes the Doorbell Register to notify the xHC that it has Device Slot
+/// related work for the xHC to perform.
+///
+/// The number of Doorbell Registers implemented by a particular instantiation of a
+/// host controller is documented in the Number of Device Slots (MaxSlots) field of
+/// the HCSPARAMS1 register (section 5.3.3).
+///
+/// These registers are pointed to by the Doorbell Offset Register (DBOFF) in the
+/// xHC Capability register space. The Doorbell Array base address shall be Dword
+/// 430 aligned and is calculated by adding the value in the DBOFF register (section
+/// 5.3.7) to “Base” (the base address of the xHCI Capability register address space).
+/// Refer to section 4.7 for more information on Doorbell registers.
+#[bitfield(u32)]
+pub struct Doorbell {
+    /// DB Target – RW. Doorbell Target. This field defines the target of the doorbell reference. The
+    /// table below defines the xHC notification that is generated by ringing the doorbell. Note that
+    /// Doorbell Register 0 is dedicated to Command Ring and decodes this field differently than the
+    /// other Doorbell Registers.
+    ///
+    /// Device Context Doorbells (1-255)
+    /// Value Definition
+    ///   0 Reserved
+    ///   1 Control EP 0 Enqueue Pointer Update
+    ///   2 EP 1 OUT Enqueue Pointer Update
+    ///   3 EP 1 IN Enqueue Pointer Update
+    ///   4 EP 2 OUT Enqueue Pointer Update
+    ///   5 EP 2 IN Enqueue Pointer Update
+    ///   … ...
+    ///   30 EP 15 OUT Enqueue Pointer Update
+    ///   31 EP 15 IN Enqueue Pointer Update
+    ///   32:247 Reserved
+    ///   248:255 Vendor Defined
+    ///
+    /// Host Controller Doorbell (0)
+    /// Value Definition
+    ///   0 Command Doorbell
+    ///   1:247 Reserved
+    ///   248:255 Vendor Defined
+    ///
+    /// This field returns ‘0’ when read and should be treated as “undefined” by software.
+    /// When the Command Doorbell is written, the DB Stream ID field shall be cleared to ‘0’.
+    db_target: u8,
+    _reserved: u8,
+
+    /// DB Stream ID - RW. Doorbell Stream ID. If the endpoint of a Device Context Doorbell defines
+    /// Streams, then this field shall be used to identify which Stream of the endpoint the doorbell
+    /// reference is targeting. System software is responsible for ensuring that the value written to this
+    /// field is valid.
+    ///
+    /// If the endpoint defines Streams (MaxPStreams > 0), then 0, 65535 (No Stream) and 65534
+    /// (Prime) are reserved Stream ID values and shall not be written to this field.
+    ///
+    /// If the endpoint does not define Streams (MaxPStreams = 0) and a non-'0' value is written to this
+    /// field, the doorbell reference shall be ignored.
+    ///
+    /// This field only applies to Device Context Doorbells and shall be cleared to ‘0’ for Host Controller
+    /// Command Doorbells.
+    ///
+    /// This field returns ‘0’ when read
+    db_stream_id: u16,
+}
+
+#[repr(transparent)]
+pub struct DoorbellPointer(VolatileRef<'static, Doorbell>);
+
+impl DoorbellPointer {
+    // Construct a new doorbell pointer.
+    fn new(doorbell: NonNull<Doorbell>) -> Self {
+        // SAFETY:
+        //  - We allocate this memory in the create
+        Self(unsafe { VolatileRef::new(doorbell) })
+    }
+
+    pub fn create_command_and_slots(
+        doorbell_physical: usize,
+        max_slots: u8,
+    ) -> (Self, Box<[Self]>) {
+        // Add one for the command doorbell.
+        let doorbell_cnt = max_slots as usize + 1;
+        let doorbell_array_size = size_of::<Doorbell>() * doorbell_cnt;
+        let doorbells: NonNull<Doorbell> = NonNull::new(
+            mammoth::mem::map_direct_physical_and_leak(doorbell_physical, doorbell_array_size),
+        )
+        .unwrap();
+        let first = DoorbellPointer::new(doorbells);
+        let remainder = (1..=max_slots)
+            .map(|offset| {
+                // SAFETY: We just allocated the array of this size above.
+                DoorbellPointer::new(unsafe { doorbells.add(offset as usize) })
+            })
+            .collect();
+        (first, remainder)
+    }
+
+    pub fn ring(&mut self, target: u8) {
+        self.0
+            .as_mut_ptr()
+            .write(Doorbell::new().with_db_target(target))
+    }
+}

rust/sys/voyageurs/src/xhci/registers/host_controller.rs

@@ -0,0 +1,511 @@
+use core::ptr::NonNull;
+
+use alloc::vec::Vec;
+use bitfield_struct::bitfield;
+use mammoth::{mem::map_direct_physical_and_leak, sync::Mutex};
+use volatile::{VolatilePtr, VolatileRef, map_field};
+
+use crate::xhci::registers::{
+    HostControllerCapabilities, HostControllerUsbPort, PortStatusAndControl,
+};
+
+#[bitfield(u32)]
+pub struct UsbCommand {
+    /// Run/Stop (R/S) – RW. Default = ‘0’. ‘1’ = Run. ‘0’ = Stop. When set to a ‘1’, the xHC proceeds with
+    /// execution of the schedule. The xHC continues execution as long as this bit is set to a ‘1’. When
+    /// this bit is cleared to ‘0’, the xHC completes any current or queued commands or TDs, and any
+    /// USB transactions associated with them, then halts.
+    ///
+    /// Refer to section 5.4.1.1 for more information on how R/S shall be managed.
+    ///
+    /// The xHC shall halt within 16 ms. after software clears the Run/Stop bit if the above conditions
+    /// have been met.
+    ///
+    /// The HCHalted (HCH) bit in the USBSTS register indicates when the xHC has finished its pending
+    /// pipelined transactions and has entered the stopped state. Software shall not write a ‘1’ to this
+    /// flag unless the xHC is in the Halted state (i.e. HCH in the USBSTS register is ‘1’). Doing so may
+    /// yield undefined results. Writing a ‘0’ to this flag when the xHC is in the Running state (i.e. HCH =
+    /// ‘0’) and any Event Rings are in the Event Ring Full state (refer to section 4.9.4) may result in lost
+    /// events.
+    ///
+    /// When this register is exposed by a Virtual Function (VF), this bit only controls the run state of
+    /// the xHC instance presented by the selected VF. Refer to section 8 for more information.
+    pub run_stop: bool,
+    /// Host Controller Reset (HCRST) – RW. Default = ‘0’. This control bit is used by software to reset
+    /// the host controller. The effects of this bit on the xHC and the Root Hub registers are similar to a
+    /// Chip Hardware Reset.
+    ///
+    /// When software writes a ‘1’ to this bit, the Host Controller resets its internal pipelines, timers,
+    /// counters, state machines, etc. to their initial value. Any transaction currently in progress on the
+    /// USB is immediately terminated. A USB reset shall not be driven on USB2 downstream ports,
+    /// however a Hot or Warm Reset79 shall be initiated on USB3 Root Hub downstream ports.
+    ///
+    /// PCI Configuration registers are not affected by this reset. All operational registers, including port
+    /// registers and port state machines are set to their initial values. Software shall reinitialize the
+    /// host controller as described in Section 4.2 in order to return the host controller to an
+    /// operational state.
+    ///
+    /// This bit is cleared to ‘0’ by the Host Controller when the reset process is complete. Software
+    /// cannot terminate the reset process early by writing a ‘0’ to this bit and shall not write any xHC
+    /// Operational or Runtime registers until while HCRST is ‘1’. Note, the completion of the xHC reset
+    /// process is not gated by the Root Hub port reset process.
+    ///
+    /// Software shall not set this bit to ‘1’ when the HCHalted (HCH) bit in the USBSTS register is a ‘0’.
+    /// Attempting to reset an actively running host controller may result in undefined behavior.
+    ///
+    /// When this register is exposed by a Virtual Function (VF), this bit only resets the xHC instance
+    /// presented by the selected VF. Refer to section 8 for more information
+    pub host_controller_reset: bool,
+    /// Interrupter Enable (INTE) – RW. Default = ‘0’. This bit provides system software with a means of
+    /// enabling or disabling the host system interrupts generated by Interrupters. When this bit is a ‘1’,
+    /// then Interrupter host system interrupt generation is allowed, e.g. the xHC shall issue an interrupt
+    /// at the next interrupt threshold if the host system interrupt mechanism (e.g. MSI, MSI-X, etc.) is
+    /// enabled. The interrupt is acknowledged by a host system interrupt specific mechanism.
+    ///
+    /// When this register is exposed by a Virtual Function (VF), this bit only enables the set of
+    /// Interrupters assigned to the selected VF. Refer to section 7.7.2 for more information.
+    pub interrupter_enable: bool,
+    /// Host System Error Enable (HSEE) – RW. Default = ‘0’. When this bit is a ‘1’, and the HSE bit in
+    /// the USBSTS register is a ‘1’, the xHC shall assert out-of-band error signaling to the host. The
+    /// signaling is acknowledged by software clearing the HSE bit. Refer to section 4.10.2.6 for more
+    /// information.
+    /// When this register is exposed by a Virtual Function (VF), the effect of the assertion of this bit on
+    /// the Physical Function (PF0) is determined by the VMM. Refer to section 8 for more information
+    pub host_system_error_enable: bool,
+    #[bits(3)]
+    __: u8,
+    /// Light Host Controller Reset (LHCRST) – RO or RW. Optional normative. Default = ‘0’. If the Light
+    /// HC Reset Capability (LHRC) bit in the HCCPARAMS1 register is ‘1’, then this flag allows the driver
+    /// to reset the xHC without affecting the state of the ports.
+    ///
+    /// A system software read of this bit as ‘0’ indicates the Light Host Controller Reset has completed
+    /// and it is safe for software to re-initialize the xHC. A software read of this bit as a ‘1’ indicates the
+    /// Light Host Controller Reset has not yet completed.
+    ///
+    /// If not implemented, a read of this flag shall always return a ‘0’.
+    ///
+    /// All registers in the Aux Power well shall maintain the values that had been asserted prior to the
+    /// Light Host Controller Reset. Refer to section 4.23.1 for more information.
+    ///
+    /// When this register is exposed by a Virtual Function (VF), this bit only generates a Light Reset to
+    /// the xHC instance presented by the selected VF, e.g. Disable the VFs’ device slots and set the
+    /// associated VF Run bit to Stopped. Refer to section 8 for more information.
+    pub light_host_controller_reset: bool,
+    /// Controller Save State (CSS) - RW. Default = ‘0’. When written by software with ‘1’ and HCHalted
+    /// (HCH) = ‘1’, then the xHC shall save any internal state (that may be restored by a subsequent
+    /// Restore State operation) and if FSC = '1' any cached Slot, Endpoint, Stream, or other Context
+    /// information (so that software may save it). When written by software with ‘1’ and HCHalted
+    /// (HCH) = ‘0’, or written with ‘0’, no Save State operation shall be performed. This flag always
+    /// returns ‘0’ when read. Refer to the Save State Status (SSS) flag in the USBSTS register for
+    /// information on Save State completion. Refer to section 4.23.2 for more information on xHC
+    ///
+    /// Save/Restore operation. Note that undefined behavior may occur if a Save State operation is
+    /// initiated while Restore State Status (RSS) = ‘1’.
+    ///
+    /// When this register is exposed by a Virtual Function (VF), this bit only controls saving the state of
+    /// the xHC instance presented by the selected VF. Refer to section 8 for more information.
+    pub controller_save_state: bool,
+    /// Controller Restore State (CRS) - RW. Default = ‘0’. When set to ‘1’, and HCHalted (HCH) = ‘1’,
+    /// then the xHC shall perform a Restore State operation and restore its internal state. When set to
+    /// ‘1’ and Run/Stop (R/S) = ‘1’ or HCHalted (HCH) = ‘0’, or when cleared to ‘0’, no Restore State
+    /// operation shall be performed. This flag always returns ‘0’ when read. Refer to the Restore State
+    /// Status (RSS) flag in the USBSTS register for information on Restore State completion. Refer to
+    /// section 4.23.2 for more information. Note that undefined behavior may occur if a Restore State
+    /// operation is initiated while Save State Status (SSS) = ‘1’.
+    /// When this register is exposed by a Virtual Function (VF), this bit only controls restoring the state
+    /// of the xHC instance presented by the selected VF. Refer to section 8 for more information.
+    pub controller_restore_state: bool,
+    /// Enable Wrap Event (EWE) - RW. Default = ‘0’. When set to ‘1’, the xHC shall generate a MFINDEX
+    /// Wrap Event every time the MFINDEX register transitions from 03FFFh to 0. When cleared to ‘0’
+    /// no MFINDEX Wrap Events are generated. Refer to section 4.14.2 for more information.
+    ///
+    /// When this register is exposed by a Virtual Function (VF), the generation of MFINDEX Wrap
+    /// Events to VFs shall be emulated by the VMM.
+    pub enable_wrap_event: bool,
+    /// Enable U3 MFINDEX Stop (EU3S) - RW. Default = ‘0’. When set to ‘1’, the xHC may stop the
+    /// MFINDEX counting action if all Root Hub ports are in the U3, Disconnected, Disabled, or
+    /// Powered-off state. When cleared to ‘0’ the xHC may stop the MFINDEX counting action if all
+    /// Root Hub ports are in the Disconnected, Disabled, Training, or Powered-off state. Refer to
+    /// section 4.14.2 for more information
+    pub enable_u3_mfindex_stop: bool,
+    ___: bool,
+    /// CEM Enable (CME) - RW. Default = '0'. When set to '1', a Max Exit Latency Too Large Capability
+    /// Error may be returned by a Configure Endpoint Command. When cleared to '0', a Max Exit
+    /// Latency Too Large Capability Error shall not be returned by a Configure Endpoint Command.
+    /// This bit is Reserved if CMC = ‘0’. Refer to section 4.23.5.2.2 for more information.
+    pub cem_enable: bool,
+    /// Extended TBC Enable (ETE). This flag indicates that the host controller implementation is
+    /// enabled to support Transfer Burst Count (TBC) values greater that 4 in isoch TDs. When this bit
+    /// is ‘1’, the Isoch TRB TD Size/TBC field presents the TBC value, and the TBC/RsvdZ field is RsvdZ.
+    /// When this bit is ‘0’, the TDSize/TCB field presents the TD Size value, and the TBC/RsvdZ field
+    /// presents the TBC value. This bit may be set only if ETC = ‘1’. Refer to section 4.11.2.3 for more
+    /// information.
+    pub extended_tbc_enable: bool,
+    /// Extended TBC TRB Status Enable (TSC_EN). This flag indicates that the host controller
+    /// implementation is enabled to support ETC_TSC capability. When this is ‘1’, TRBSts field in the
+    /// TRB updated to indicate if it is last transfer TRB in the TD. This bit may be set only if
+    /// ETC_TSC=’1’. Refer to section 4.11.2.3 for more information.
+    pub extended_tbc_trb_status_enable: bool,
+    /// VTIO Enable (VTIOE) – RW. Default = ‘0’. When set to ‘1’, XHCI HW will enable its VTIO
+    /// capability and begin to use the information provided via that VTIO Registers to determine its
+    /// DMA-ID. When cleared to ‘0’, XHCI HW will use the Primary DMA-ID for all accesses. This bit
+    /// may be set only if VTC = ‘1’.
+    pub vtio_enable: bool,
+    #[bits(15)]
+    ____: u16,
+}
+
+#[bitfield(u32)]
+pub struct UsbStatus {
+    /// HCHalted (HCH) – RO. Default = ‘1’. This bit is a ‘0’ whenever the Run/Stop (R/S) bit is a ‘1’. The
+    /// xHC sets this bit to ‘1’ after it has stopped executing as a result of the Run/Stop (R/S) bit being
+    /// cleared to ‘0’, either by software or by the xHC hardware (e.g. internal error).
+    ///
+    /// If this bit is '1', then SOFs, microSOFs, or Isochronous Timestamp Packets (ITP) shall not be
+    /// generated by the xHC, and any received Transaction Packet shall be dropped.
+    ///
+    /// When this register is exposed by a Virtual Function (VF), this bit only reflects the Halted state of
+    /// the xHC instance presented by the selected VF. Refer to section 8 for more information
+    #[bits(access=RO)]
+    pub host_controller_halted: bool,
+    __: bool,
+    /// Host System Error (HSE) – RW1C. Default = ‘0’. The xHC sets this bit to ‘1’ when a serious error
+    /// is detected, either internal to the xHC or during a host system access involving the xHC module.
+    /// (In a PCI system, conditions that set this bit to ‘1’ include PCI Parity error, PCI Master Abort, and
+    /// PCI Target Abort.) When this error occurs, the xHC clears the Run/Stop (R/S) bit in the USBCMD
+    /// register to prevent further execution of the scheduled TDs. If the HSEE bit in the USBCMD
+    /// register is a ‘1’, the xHC shall also assert out-of-band error signaling to the host. Refer to section
+    /// 4.10.2.6 for more information.
+    /// When this register is exposed by a Virtual Function (VF), the assertion of this bit affects all VFs
+    /// and reflects the Host System Error state of the Physical Function (PF0). Refer to section 8 for
+    /// more information.
+    pub host_system_error: bool,
+    /// Event Interrupt (EINT) – RW1C. Default = ‘0’. The xHC sets this bit to ‘1’ when the Interrupt
+    /// Pending (IP) bit of any Interrupter transitions from ‘0’ to ‘1’. Refer to section 7.1.2 for use.
+    /// Software that uses EINT shall clear it prior to clearing any IP flags. A race condition may occur if
+    /// software clears the IP flags then clears the EINT flag, and between the operations another IP ‘0’
+    /// to '1' transition occurs. In this case the new IP transition shall be lost.
+    /// When this register is exposed by a Virtual Function (VF), this bit is the logical 'OR' of the IP bits
+    /// for the Interrupters assigned to the selected VF. And it shall be cleared to ‘0’ when all associated
+    /// interrupter IP bits are cleared, i.e. all the VF’s Interrupter Event Ring(s) are empty. Refer to
+    /// section 8 for more information
+    pub event_interrupt: bool,
+    /// Port Change Detect (PCD) – RW1C. Default = ‘0’. The xHC sets this bit to a ‘1’ when any port has
+    /// a change bit transition from a ‘0’ to a ‘1’.
+    ///
+    /// This bit is allowed to be maintained in the Aux Power well. Alternatively, it is also acceptable
+    /// that on a D3 to D0 transition of the xHC, this bit is loaded with the OR of all of the PORTSC
+    /// change bits. Refer to section 4.19.3.
+    ///
+    /// This bit provides system software an efficient means of determining if there has been Root Hub
+    /// port activity. Refer to section 4.15.2.3 for more information.
+    ///
+    /// When this register is exposed by a Virtual Function (VF), the VMM determines the state of this
+    /// bit as a function of the Root Hub Ports associated with the Device Slots assigned to the selected
+    /// VF. Refer to section 8 for more information.
+    pub port_change_detect: bool,
+    #[bits(3)]
+    __: u8,
+    /// Save State Status (SSS) - RO. Default = ‘0’. When the Controller Save State (CSS) flag in the
+    /// USBCMD register is written with ‘1’ this bit shall be set to ‘1’ and remain 1 while the xHC saves
+    /// its internal state. When the Save State operation is complete, this bit shall be cleared to ‘0’.
+    /// Refer to section 4.23.2 for more information.
+    ///
+    /// When this register is exposed by a Virtual Function (VF), the VMM determines the state of this
+    /// bit as a function of the saving the state for the selected VF. Refer to section 8 for more
+    /// information.
+    #[bits(access=RO)]
+    pub save_state_status: bool,
+    /// Restore State Status (RSS) - RO. Default = ‘0’. When the Controller Restore State (CRS) flag in
+    /// the USBCMD register is written with ‘1’ this bit shall be set to ‘1’ and remain 1 while the xHC
+    /// restores its internal state. When the Restore State operation is complete, this bit shall be
+    /// cleared to ‘0’. Refer to section 4.23.2 for more information.
+    ///
+    /// When this register is exposed by a Virtual Function (VF), the VMM determines the state of this
+    /// bit as a function of the restoring the state for the selected VF. Refer to section 8 for more
+    /// information.
+    #[bits(access=RO)]
+    pub restore_state_status: bool,
+    /// Save/Restore Error (SRE) - RW1C. Default = ‘0’. If an error occurs during a Save or Restore
+    /// operation this bit shall be set to ‘1’. This bit shall be cleared to ‘0’ when a Save or Restore
+    /// operation is initiated or when written with ‘1’. Refer to section 4.23.2 for more information.
+    /// When this register is exposed by a Virtual Function (VF), the VMM determines the state of this
+    /// bit as a function of the Save/Restore completion status for the selected VF. Refer to section 8
+    /// for more information.
+    pub save_restore_error: bool,
+    /// Controller Not Ready (CNR) – RO. Default = ‘1’. ‘0’ = Ready and ‘1’ = Not Ready. Software shall
+    /// not write any Doorbell or Operational register of the xHC, other than the USBSTS register, until
+    /// CNR = ‘0’. This flag is set by the xHC after a Chip Hardware Reset and cleared when the xHC is
+    /// ready to begin accepting register writes. This flag shall remain cleared (‘0’) until the next Chip
+    /// Hardware Reset.
+    #[bits(access=RO)]
+    pub controller_not_ready: bool,
+    /// Host Controller Error (HCE) – RO. Default = 0. 0’ = No internal xHC error conditions exist and ‘1’
+    /// = Internal xHC error condition. This flag shall be set to indicate that an internal error condition
+    /// has been detected which requires software to reset and reinitialize the xHC. Refer to section
+    /// 4.24.1 for more information.
+    #[bits(access=RO)]
+    pub host_controller_error: bool,
+    #[bits(19)]
+    __: u32,
+}
+
+impl UsbStatus {
+    // Returns a copy of this object that can be written without overwritting flags that are RW1C.
+    fn preserving_flags(&self) -> UsbStatus {
+        self.with_host_system_error(false)
+            .with_event_interrupt(false)
+            .with_port_change_detect(false)
+            .with_save_restore_error(false)
+    }
+}
+
+/// Internal data structure to ensure 64 bit reads and writes.
+#[bitfield(u64)]
+struct CommandAndStatus {
+    #[bits(32)]
+    usb_command: UsbCommand,
+    #[bits(32)]
+    usb_status: UsbStatus,
+}
+
+impl CommandAndStatus {
+    fn update_command(&self, f: impl Fn(UsbCommand) -> UsbCommand) -> CommandAndStatus {
+        CommandAndStatus::new()
+            .with_usb_command(f(self.usb_command()))
+            .with_usb_status(self.usb_status().preserving_flags())
+    }
+
+    fn update_status(&self, f: impl Fn(UsbStatus) -> UsbStatus) -> CommandAndStatus {
+        self.with_usb_status(f(self.usb_status()).preserving_flags())
+    }
+}
+
+#[bitfield(u64)]
+struct PageSize {
+    ///Page Size – RO. Default = Implementation defined. This field defines the page size supported by
+    /// the xHC implementation. This xHC supports a page size of 2^(n+12) if bit n is Set. For example, if
+    /// bit 0 is Set, the xHC supports 4k byte page sizes.
+    ///
+    /// For a Virtual Function, this register reflects the page size selected in the System Page Size field
+    /// of the SR-IOV Extended Capability structure. For the Physical Function 0, this register reflects
+    /// the implementation dependent default xHC page size.
+    ///
+    /// Various xHC resources reference PAGESIZE to describe their minimum alignment requirements.
+    ///
+    /// The maximum possible page size is 128M.
+    #[bits(access=RO)]
+    page_size: u32,
+    __: u32,
+}
+
+#[bitfield(u64)]
+struct DeviceNotificationControl {
+    __: u32,
+    /// This register is used by software to enable or disable the reporting of the
+    /// reception of specific USB Device Notification Transaction Packets. A Notification
+    /// Enable (Nx, where x = 0 to 15) flag is defined for each of the 16 possible de vice
+    /// notification types. If a flag is set for a specific notification type, a Device
+    /// Notification Event shall be generated when the respective notification packet is
+    /// received. After reset all notifications are disabled. Refer to section 6.4.2.7
+    device_notification_control: u32,
+}
+
+#[bitfield(u64)]
+pub struct UsbConfigure {
+    /// Max Device Slots Enabled (MaxSlotsEn) – RW. Default = ‘0’. This field specifies the maximum
+    /// number of enabled Device Slots. Valid values are in the range of 0 to MaxSlots. Enabled Devices
+    /// Slots are allocated contiguously. e.g. A value of 16 specifies that Device Slots 1 to 16 are active.
+    ///
+    /// A value of ‘0’ disables all Device Slots. A disabled Device Slot shall not respond to Doorbell
+    /// Register references.
+    ///
+    /// This field shall not be modified by software if the xHC is running (Run/Stop (R/S) = ‘1’)
+    pub max_device_slots_enabled: u8,
+    /// U3 Entry Enable (U3E) – RW. Default = '0'. When set to '1', the xHC shall assert the PLC flag ('1')
+    /// when a Root Hub port transitions to the U3 State. Refer to section 4.15.1 for more information.
+    pub u3_entry_enable: bool,
+    /// Configuration Information Enable (CIE) - RW. Default = '0'. When set to '1', the software shall
+    /// initialize the Configuration Value, Interface Number, and Alternate Setting fields in the Input
+    /// Control Context when it is associated with a Configure Endpoint Command. When this bit is '0',
+    /// the extended Input Control Context fields are not supported. Refer to section 6.2.5.1 for more
+    /// information.
+    pub configuration_information_enable: bool,
+
+    #[bits(22)]
+    __: u32,
+
+    // Pad to 64 bits for the purposes of reads and writes.
+    __: u32,
+}
+
+/// XHCI Spec Section 5.4
+///
+/// > The base address of this register space is referred to as Operational Base. The
+/// Operational Base shall be Dword aligned and is calculated by adding the value
+/// of the Capability Registers Length (CAPLENGTH) register (refer to Section 5.3.1)
+/// to the Capability Base address. All registers are multiples of 32 bits in length
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct HostControllerOperational {
+    command_and_status: CommandAndStatus,
+    page_size: PageSize,
+    device_notification_control: DeviceNotificationControl,
+    /// Bit 0: Ring Cycle State (RW)
+    /// Bit 1: Command Stop (RW1S)
+    /// Bit 2: Command Abort (RW1S)
+    /// Bit 3: Command Ring Running (RO)
+    command_ring_control: u64,
+    __: u64,
+    ___: u64,
+    /// The Device Context Base Address Array Pointer Register identifies the base
+    /// address of the Device Context Base Address Array.
+    /// The memory structure referenced by this physical memory pointer is assumed to
+    /// be physically contiguous and 64-byte aligned.
+    device_context_base_address_array_pointer: u64,
+    configure: UsbConfigure,
+}
+
+const _: () = assert!(size_of::<HostControllerOperational>() == 0x40);
+
+pub struct HostControllerOperationalWrapper {
+    operational: Mutex<VolatileRef<'static, HostControllerOperational>>,
+    // TODO: This should maybe be its own structure.
+    ports: Vec<Mutex<VolatileRef<'static, HostControllerUsbPort>>>,
+}
+
+#[allow(dead_code)]
+impl HostControllerOperationalWrapper {
+    pub fn new(mmio_address: usize) -> (Self, HostControllerCapabilities) {
+        const MAP_SIZE: usize = 0x1000;
+        let caps_ptr: *mut HostControllerCapabilities =
+            map_direct_physical_and_leak(mmio_address, MAP_SIZE);
+
+        // SAFETY:
+        //  - The pointer is valid.
+        //  - No other thread has access in this block.
+        let capabilities = unsafe {
+            VolatilePtr::new(
+                // UNWRAP: We just constructed this object with a non-null value.
+                NonNull::new(caps_ptr).unwrap(),
+            )
+            .read()
+        };
+
+        assert!(
+            capabilities.cap_params_1.supports_64_bit(),
+            "We only support 64 bit XHCI"
+        );
+
+        // TODO: I don't think we acutally handle this properly.
+        // SAFETY: XHCI Spec says that this resides in a single page of memory which we mapped
+        // above.
+        //
+        // BAR0 Size Allocation
+        // If virtualization is supported, the Capability and Operational Register sets, and
+        // the Extended Capabilities may reside in a single page of virtual memory,
+        let cap_length_and_version = capabilities.cap_length_and_version;
+        let operational_ptr = unsafe {
+            (caps_ptr as *mut u8).add(cap_length_and_version.cap_length() as usize)
+                as *mut HostControllerOperational
+        };
+
+        const PORT_OFFSET: usize = 0x400;
+
+        // FIXME: This calculation is cursed.
+        let ports_addr = unsafe { (operational_ptr as *mut u8).add(PORT_OFFSET) as usize };
+        let ports_space = MAP_SIZE - cap_length_and_version.cap_length() as usize - PORT_OFFSET;
+        let max_ports_we_support = ports_space / size_of::<HostControllerUsbPort>();
+        let max_ports = capabilities.params_1.max_ports();
+        assert!(
+            max_ports as usize <= max_ports_we_support,
+            "TODO: Support more ports."
+        );
+
+        let mut ports = Vec::new();
+        let ports_addr = ports_addr as *mut HostControllerUsbPort;
+        for port_index in 0..max_ports {
+            ports.push(unsafe {
+                Mutex::new(VolatileRef::new(
+                    NonNull::new(ports_addr.add(port_index as usize)).unwrap(),
+                ))
+            });
+        }
+
+        let operational = Self {
+            operational: Mutex::new(unsafe {
+                VolatileRef::new(NonNull::new(operational_ptr).unwrap())
+            }),
+            ports,
+        };
+
+        (operational, capabilities)
+    }
+
+    pub fn read_command(&self) -> UsbCommand {
+        let locked = self.operational.lock();
+        let op = locked.as_ptr();
+        map_field!(op.command_and_status).read().usb_command()
+    }
+
+    pub fn update_command(&self, f: impl Fn(UsbCommand) -> UsbCommand) {
+        let mut locked = self.operational.lock();
+        let op = locked.as_mut_ptr();
+        map_field!(op.command_and_status).update(|c_and_s| c_and_s.update_command(f));
+    }
+
+    pub fn read_status(&self) -> UsbStatus {
+        let locked = self.operational.lock();
+        let op = locked.as_ptr();
+        map_field!(op.command_and_status).read().usb_status()
+    }
+
+    pub fn update_status(&self, f: impl Fn(UsbStatus) -> UsbStatus) {
+        let mut locked = self.operational.lock();
+        let op = locked.as_mut_ptr();
+        map_field!(op.command_and_status).update(|c_and_s| c_and_s.update_status(f));
+    }
+
+    pub fn set_device_context_base_address_array_pointer(&self, pointer: usize) {
+        let mut locked = self.operational.lock();
+        let op = locked.as_mut_ptr();
+        map_field!(op.device_context_base_address_array_pointer).write(pointer as u64);
+    }
+
+    pub fn set_command_ring_dequeue_pointer(&self, pointer: usize, cycle_bit: bool) {
+        // TODO: Assert that the command ring is not running here.
+        let mut locked = self.operational.lock();
+        let op = locked.as_mut_ptr();
+        map_field!(op.command_ring_control).write(pointer as u64 | cycle_bit as u64);
+    }
+
+    pub fn read_configure(&self) -> UsbConfigure {
+        let locked = self.operational.lock();
+        let op = locked.as_ptr();
+        map_field!(op.configure).read()
+    }
+
+    pub fn update_configure(&self, f: impl Fn(UsbConfigure) -> UsbConfigure) {
+        let mut locked = self.operational.lock();
+        let op = locked.as_mut_ptr();
+        map_field!(op.configure).update(f);
+    }
+
+    pub fn get_port(&self, index: usize) -> HostControllerUsbPort {
+        self.ports[index].lock().as_ptr().read()
+    }
+
+    pub fn update_port_status(
+        &self,
+        index: usize,
+        f: impl Fn(PortStatusAndControl) -> PortStatusAndControl,
+    ) {
+        let mut port_ref = self.ports[index].lock();
+        let ptr = port_ref.as_mut_ptr();
+        map_field!(ptr.status_and_control).update(f);
+    }
+
+    pub fn num_ports(&self) -> usize {
+        self.ports.len()
+    }
+}

rust/sys/voyageurs/src/xhci/registers/host_controller_port.rs

@@ -0,0 +1,415 @@
+use bitfield_struct::bitfield;
+
+/// A host controller shall implement one or more port registers. The number of
+/// port registers implemented by a particular instantiation of a host controller is
+/// documented in the HCSPARAMS1 register (Section 5.3.3). Software uses this
+/// information as an input parameter to determine how many ports need to be
+/// serviced.
+///
+/// XHCI Spec 5.4.8
+#[bitfield(u32)]
+pub struct PortStatusAndControl {
+    /// Current Connect Status (CCS) – ROS. Default = ‘0’. ‘1’ = A device is connected81 to the port. ‘0’ =
+    /// A device is not connected. This value reflects the current state of the port, and may not
+    /// correspond directly to the event that caused the Connect Status Change (CSC) bit to be set to ‘1’.
+    ///
+    /// Refer to sections 4.19.3 and 4.19.4 for more details on the Connect Status Change (CSC)
+    /// assertion conditions.
+    /// This flag is ‘0’ if PP is ‘0’.
+    #[bits(access=RO)]
+    pub current_connect_status: bool,
+
+    /// Port Enabled/Disabled (PED) – RW1CS. Default = ‘0’. ‘1’ = Enabled. ‘0’ = Disabled.
+    /// Ports may only be enabled by the xHC. Software cannot enable a port by writing a ‘1’ to this flag.
+    ///
+    /// A port may be disabled by software writing a ‘1’ to this flag.
+    ///
+    /// This flag shall automatically be cleared to ‘0’ by a disconnect event or other fault condition.
+    /// Note that the bit status does not change until the port state actually changes. There may be a
+    /// delay in disabling or enabling a port due to other host controller or bus events.
+    ///
+    /// When the port is disabled (PED = ‘0’) downstream propagation of data is blocked on this port,
+    /// except for reset.
+    ///
+    /// For USB2 protocol ports:
+    /// When the port is in the Disabled state, software shall reset the port (PR = ‘1’) to transition PED to
+    /// ‘1’ and the port to the Enabled state.
+    ///
+    /// For USB3 protocol ports:
+    /// When the port is in the Polling state (after detecting an attach), the port shall automatically
+    /// transition to the Enabled state and set PED to ‘1’ upon the completion of successful link training.
+    /// When the port is in the Disabled state, software shall write a ‘5’ (RxDetect) to the PLS field to
+    /// transition the port to the Disconnected state. Refer to section 4.19.1.2.
+    ///
+    /// PED shall automatically be cleared to ‘0’ when PR is set to ‘1’, and set to ‘1’ when PR transitions
+    /// from ‘1’ to ‘0’ after a successful reset. Refer to Port Reset (PR) bit for more information on how
+    /// the PED bit is managed.
+    ///
+    /// Note that when software writes this bit to a ‘1’, it shall also write a ‘0’ to the PR bit.
+    /// This flag is ‘0’ if PP is ‘0’.
+    pub port_enabled_disabled: bool,
+
+    __: bool,
+
+    /// Over-current Active (OCA) – RO. Default = ‘0’. ‘1’ = This port currently has an over-current
+    /// condition. ‘0’ = This port does not have an over-current condition. This bit shall automatically
+    /// transition from a ‘1’ to a ‘0’ when the over-current condition is removed.
+    #[bits(access=RO)]
+    pub over_current_active: bool,
+
+    /// Port Reset (PR) – RW1S. Default = ‘0’. ‘1’ = Port Reset signaling is asserted. ‘0’ = Port is not in
+    /// Reset. When software writes a ‘1’ to this bit generating a ‘0’ to ‘1’ transition, the bus reset
+    /// sequence is initiated83; USB2 protocol ports shall execute the bus reset sequence as defined in
+    /// the USB2 Spec. USB3 protocol ports shall execute the Hot Reset sequence as defined in the
+    /// USB3 Spec. PR remains set until reset signaling is completed by the root hub.
+    ///
+    /// Note that software shall write a ‘1’ to this flag to transition a USB2 port from the Polling state to
+    /// the Enabled state. Refer to sections 4.15.2.3 and 4.19.1.1.
+    ///
+    /// This flag is ‘0’ if PP is ‘0’.
+    pub port_reset: bool,
+
+    /// Port Link State (PLS) – RWS. Default = RxDetect (‘5’). This field is used to power manage the port
+    /// and reflects its current link state.
+    ///
+    /// When the port is in the Enabled state, system software may set the link U state by writing this
+    /// field. System software may also write this field to force a Disabled to Disconnected state
+    /// transition of the port.
+    ///
+    /// Write Value Description
+    /// 0 The link shall transition to a U0 state from any of the U states.
+    /// 285 USB2 protocol ports only. The link should transition to the U2 State.
+    /// 384 The link shall transition to a U3 state from the U0 state. This action
+    /// selectively suspends the device connected to this port. While the Port
+    /// Link State = U3, the hub does not propagate downstream-directed
+    /// traffic to this port, but the hub shall respond to resume signaling from
+    /// the port.
+    /// 5 USB3 protocol ports only. If the port is in the Disabled state (PLS =
+    /// Disabled, PP = 1), then the link shall transition to a RxDetect state and
+    /// the port shall transition to the Disconnected state, else ignored.
+    /// 10 USB3 protocol ports only. Shall enable a link transition to the
+    /// Compliance state, i.e. CTE = ‘1’. Refer to section 4.19.1.2.4.1 for more
+    /// information.
+    /// 185,4,6-9,11-14 Ignored.
+    /// 15 USB2 protocol ports only. If the port is in the U3 state (PLS = U3), then
+    /// the link shall remain in the U3 state and the port shall transition to the
+    /// Resume substate, else ignored. Refer to section 4.15.2 for more
+    /// information.
+    ///
+    /// Note: The Port Link State Write Strobe (LWS) shall also be set to ‘1’ to write this
+    /// field.
+    ///
+    /// For USB2 protocol ports: Writing a value of '2' to this field shall request LPM, asserting L1
+    /// signaling on the USB2 bus. Software may read this field to determine if the transition to the U2
+    /// state was successful. Writing a value of '0' shall deassert L1 signaling on the USB. Writing a value
+    /// of '1' shall have no effect. The U1 state shall never be reported by a USB2 protocol port.
+    ///
+    /// Read Value Meaning
+    /// 0 Link is in the U0 State
+    /// 1 Link is in the U1 State
+    /// 2 Link is in the U2 State
+    /// 3 Link is in the U3 State (Device Suspended)
+    /// 4 Link is in the Disabled State86
+    /// 5 Link is in the RxDetect State87
+    /// 6 Link is in the Inactive State88
+    /// 7 Link is in the Polling State
+    /// 8 Link is in the Recovery State
+    /// 9 Link is in the Hot Reset State
+    /// 10 Link is in the Compliance Mode State
+    /// 11 Link is in the Test Mode89 State
+    /// 12-14 Reserved
+    /// 15 Link is in the Resume State90
+    ///
+    /// This field is undefined if PP = ‘0’.
+    ///
+    /// Note: Transitions between different states are not reflected until the transition is complete. Refer
+    /// to section 4.19 for PLS transition conditions.
+    /// 409
+    ///
+    /// Refer to sections 4.15.2 and 4.23.5 for more information on the use of this field. Refer to the
+    /// USB2 LPM ECR for more information on USB link power management operation. Refer to section
+    /// 7.2 for supported USB protocols
+    #[bits(4)]
+    pub port_link_status: u8,
+    /// Port Power (PP) – RWS. Default = ‘1’. This flag reflects a port's logical, power control state.
+    /// Because host controllers can implement different methods of port power switching, this flag may
+    /// or may not represent whether (VBus) power is actually applied to the port. When PP equals a '0'
+    /// the port is nonfunctional and shall not report attaches, detaches, or Port Link State (PLS)
+    /// changes. However, the port shall report over-current conditions when PP = ‘0’ if PPC = ‘0’. After
+    /// modifying PP, software shall read PP and confirm that it is reached its target state before
+    /// modifying it again91, undefined behavior may occur if this procedure is not followed.
+    ///
+    /// 0 = This port is in the Powered-off state.
+    /// 1 = This port is not in the Powered-off state.
+    ///
+    /// If the Port Power Control (PPC) flag in the HCCPARAMS1 register is '1', then xHC has port power
+    /// control switches and this bit represents the current setting of the switch ('0' = off, '1' = on).
+    ///
+    /// If the Port Power Control (PPC) flag in the HCCPARAMS1 register is '0', then xHC does not have
+    /// port power control switches and each port is hard wired to power, and not affected by this bit.
+    /// When an over-current condition is detected on a powered port, the xHC shall transition the PP
+    /// bit in each affected port from a ‘1’ to ‘0’ (removing power from the port).
+    ///
+    /// Note: If this is an SSIC Port, then the DSP Disconnect process is initiated by '1' to '0' transition of
+    /// PP. After an SSIC USP disconnect process, the port may be disabled by setting PED = 1. As noted,
+    /// the SSIC spec does not define a mechanism for the USP to request DSP to be re-enabled for a
+    /// subsequent re-connect. If PED is set to 1 without a prior negotiated disconnect with the USP,
+    /// subsequent re-enabling of the port requires DSP to issue a WPR to bring USP back to Rx.Detect.
+    ///
+    /// Refer to section 5.1.2 in the SSIC Spec for more information.
+    /// Refer to section 4.19.4 for more information.
+    pub port_power: bool,
+    /// Port Speed (Port Speed) – ROS. Default = ‘0’. This field identifies the speed of the connected
+    /// USB Device. This field is only relevant if a device is connected (CCS = ‘1’) in all other cases this
+    /// field shall indicate Undefined Speed. Refer to section 4.19.3.
+    ///
+    /// Value Meaning
+    /// 0 Undefined Speed
+    /// 1 -15 Protocol Speed ID (PSI), refer to section 7.2.1 for the definition of PSIV
+    /// field in the PSI Dword
+    ///
+    /// Note: This field is invalid on a USB2 protocol port until after the port is reset.
+    #[bits(4)]
+    pub port_speed: u8,
+    /// Port Indicator Control (PIC) – RWS. Default = 0. Writing to these bits has no effect if the Port
+    /// Indicators (PIND) bit in the HCCPARAMS1 register is a ‘0’. If PIND bit is a ‘1’, then the bit
+    /// encodings are:
+    ///
+    /// Value Meaning
+    /// 0 Port indicators are off
+    /// 1 Amber
+    /// 2 Green
+    /// 3 Undefined
+    ///
+    /// Refer to the USB2 Specification section 11.5.3 for a description on how these bits shall be used.
+    /// This field is ‘0’ if PP is ‘0’
+    #[bits(2)]
+    pub port_indicator_control: u8,
+    /// Port Link State Write Strobe (LWS) – RW. Default = ‘0’. When this bit is set to ‘1’ on a write
+    /// reference to this register, this flag enables writes to the PLS field. When ‘0’, write data in PLS field
+    /// is ignored. Reads to this bit return ‘0’
+    pub port_link_state_write_strobe: bool,
+    /// Connect Status Change (CSC) – RW1CS. Default = ‘0’. ‘1’ = Change in CCS. ‘0’ = No change. This
+    /// flag indicates a change has occurred in the port’s Current Connect Status (CCS) or Cold Attach
+    /// Status (CAS) bits. Note that this flag shall not be set if the CCS transition was due to software
+    /// setting PP to ‘0’, or the CAS transition was due to software setting WPR to ‘1’. The xHC sets this
+    /// bit to ‘1’ for all changes to the port device connect status92, even if system software has not
+    /// cleared an existing Connect Status Change. For example, the insertion status changes twice
+    /// before system software has cleared the changed condition, root hub hardware will be “setting”
+    /// an already-set bit (i.e., the bit will remain ‘1’). Software shall clear this bit by writing a ‘1’ to it.
+    /// Refer to section 4.19.2 for more information on change bit usage.
+    pub connect_status_change: bool,
+    /// Port Enabled/Disabled Change (PEC) – RW1CS. Default = ‘0’. ‘1’ = change in PED. ‘0’ = No
+    /// change. Note that this flag shall not be set if the PED transition was due to software setting PP to
+    /// ‘0’. Software shall clear this bit by writing a ‘1’ to it. Refer to section 4.19.2 for more information
+    /// on change bit usage.
+    ///
+    /// For a USB2 protocol port, this bit shall be set to ‘1’ only when the port is disabled due to the
+    /// appropriate conditions existing at the EOF2 point (refer to section 11.8.1 of the USB2
+    ///
+    /// Specification for the definition of a Port Error).
+    /// For a USB3 protocol port, this bit shall never be set to ‘1’.
+    pub port_enabled_disabled_change: bool,
+    /// Warm Port Reset Change (WRC) – RW1CS/RsvdZ. Default = ‘0’. This bit is set when Warm Reset
+    /// processing on this port completes. ‘0’ = No change. ‘1’ = Warm Reset complete. Note that this
+    /// flag shall not be set to ‘1’ if the Warm Reset processing was forced to terminate due to software
+    /// clearing PP or PED to '0'. Software shall clear this bit by writing a '1' to it. Refer to section 4.19.5.1.
+    /// Refer to section 4.19.2 for more information on change bit usage.
+    ///
+    /// This bit only applies to USB3 protocol ports. For USB2 protocol ports it shall be RsvdZ.
+    pub warm_port_reset_change: bool,
+    /// Over-current Change (OCC) – RW1CS. Default = ‘0’. This bit shall be set to a ‘1’ when there is a ‘0’
+    /// to ‘1’ or ‘1’ to ‘0’ transition of Over-current Active (OCA). Software shall clear this bit by writing a
+    /// ‘1’ to it. Refer to section 4.19.2 for more information on change bit usage.
+    pub over_current_change: bool,
+    /// Port Reset Change (PRC) – RW1CS. Default = ‘0’. This flag is set to ‘1’ due to a '1' to '0' transition
+    /// of Port Reset (PR). e.g. when any reset processing (Warm or Hot) on this port is complete. Note
+    /// that this flag shall not be set to ‘1’ if the reset processing was forced to terminate due to software
+    /// clearing PP or PED to '0'. ‘0’ = No change. ‘1’ = Reset complete. Software shall clear this bit by
+    /// writing a '1' to it. Refer to section 4.19.5. Refer to section 4.19.2 for more information on change
+    /// bit usage
+    pub port_reset_change: bool,
+    /// Port Link State Change (PLC) – RW1CS. Default = ‘0’. This flag is set to ‘1’ due to the following
+    /// PLS transitions:
+    ///
+    /// Transition Condition
+    /// U3 -> Resume: Wakeup signaling from a device
+    /// Resume -> Recovery -> U0: Device Resume complete (USB3 protocol ports
+    /// only)
+    /// Resume -> U0: Device Resume complete (USB2 protocol ports
+    /// only)
+    /// U3 -> Recovery -> U0: Software Resume complete (USB3 protocol ports
+    /// only)
+    /// U3 -> U0: Software Resume complete (USB2 protocol ports
+    /// only)
+    /// U2 -> U0: L1 Resume complete (USB2 protocol ports only)93
+    /// U0 -> U0: L1 Entry Reject (USB2 protocol ports only)93
+    /// Any state -> Inactive: Error (USB3 protocol ports only).
+    ///     Note: PLC is asserted only on the first LTSSM
+    ///     SS.Inactive.Disconnect.Detect to SS.Inactive.Quiet
+    ///     substate transition after entering the SS.Inactive
+    ///     state.
+    /// Any State -> U3: U3 Entry complete. Note: PLC is asserted only if
+    /// U3E = ‘1’.
+    ///
+    /// Note that this flag shall not be set if the PLS transition was due to software
+    /// setting PP to ‘0’. Refer to section 4.23.5 for more information. '0' = No
+    /// change. '1' = Link Status Changed. Software shall clear this bit by
+    /// writing a '1' to it. Refer to “PLC Condition:” references in section 4.19.1
+    /// for the specific port state transitions that set this flag. Refer to section
+    /// 4.19.2 for more information on change bit usage.
+    pub port_link_state_change: bool,
+    /// Port Config Error Change (CEC) – RW1CS/RsvdZ. Default = ‘0’. This flag indicates that the port
+    /// failed to configure its link partner. 0 = No change. 1 = Port Config Error detected. Software shall
+    /// clear this bit by writing a '1' to it. Refer to section 4.19.2 for more information on change bit
+    /// usage.
+    ///
+    /// Note: This flag is valid only for USB3 protocol ports. For USB2 protocol ports this bit shall be
+    /// RsvdZ.
+    pub port_config_error_change: bool,
+    /// Cold Attach Status (CAS) – RO. Default = ‘0’. ‘1’ = Far-end Receiver Terminations were detected
+    /// in the Disconnected state and the Root Hub Port State Machine was unable to advance to the
+    /// Enabled state. Refer to sections 4.19.8 for more details on the Cold Attach Status (CAS) assertion
+    /// conditions. Software shall clear this bit by writing a '1' to WPR or the xHC shall clear this bit if CCS
+    /// transitions to ‘1’.
+    /// This flag is ‘0’ if PP is ‘0’ or for USB2 protocol ports
+    #[bits(access=RO)]
+    pub cold_attach_status: bool,
+    /// Wake on Connect Enable (WCE) – RWS. Default = ‘0’. Writing this bit to a ‘1’ enables the port to
+    /// be sensitive to device connects as system wake-up events96. Refer to section 4.15 for operational
+    /// model.
+    pub wake_on_connect_enable: bool,
+    /// Wake on Disconnect Enable (WDE) – RWS. Default = ‘0’. Writing this bit to a ‘1’ enables the port
+    /// to be sensitive to device disconnects as system wake-up events. Refer to section 4.15 for
+    /// operational model.
+    pub wake_on_disconnect_enable: bool,
+    /// Wake on Over-current Enable (WOE) – RWS. Default = ‘0’. Writing this bit to a ‘1’ enables the
+    /// port to be sensitive to over-current conditions as system wake-up events96. Refer to section 4.15
+    /// for operational model.
+    pub wake_on_overcurrent_enable: bool,
+    __: bool,
+    __: bool,
+    /// Device Removable97 (DR) - RO. This flag indicates if this port has a removable device attached.
+    /// ‘1’ = Device is non-removable. ‘0’ = Device is removable.
+    #[bits(access=RO)]
+    pub device_removable: bool,
+    /// Warm Port Reset (WPR) – RW1S/RsvdZ. Default = ‘0’. When software writes a ‘1’ to this bit, the
+    /// Warm Reset sequence as defined in the USB3 Specification is initiated and the PR flag is set to ‘1’.
+    /// Once initiated, the PR, PRC, and WRC flags shall reflect the progress of the Warm Reset
+    /// sequence. This flag shall always return ‘0’ when read. Refer to section 4.19.5.1.
+    /// This flag only applies to USB3 protocol ports. For USB2 protocol ports it shall be RsvdZ.
+    pub warm_port_reset: bool,
+}
+
+impl PortStatusAndControl {
+    pub fn clear_change_bits(&self) -> Self {
+        PortStatusAndControl::new()
+            .with_connect_status_change(true)
+            .with_port_enabled_disabled_change(true)
+            .with_warm_port_reset_change(true)
+            .with_over_current_change(true)
+            .with_port_reset_change(true)
+            .with_port_link_state_change(true)
+            .with_port_config_error_change(true)
+            .with_port_power(self.port_power())
+            .with_wake_on_connect_enable(self.wake_on_connect_enable())
+            .with_wake_on_disconnect_enable(self.wake_on_disconnect_enable())
+            .with_wake_on_overcurrent_enable(self.wake_on_overcurrent_enable())
+    }
+}
+
+/// XHCI Spec 5.4.9
+/// NOTE: This definition is USB3 only.
+#[bitfield(u32)]
+pub struct PortPowerManagementStatusAndControl {
+    /// U1 Timeout – RWS. Default = ‘0’. Timeout value for U1 inactivity timer. If equal to FFh, the port
+    /// is disabled from initiating U1 entry. This field shall be set to ‘0’ by the assertion of PR to ‘1’. Refer
+    /// to section 4.19.4.1 for more information on U1 Timeout operation. The following are
+    /// permissible values:
+    ///
+    /// Value Description
+    /// 00h Zero (default)
+    /// 01h 1 μs.
+    /// 02h 2 μs.
+    /// …
+    /// 7Fh 127 μs.
+    /// 80h–FEh Reserved
+    /// FFh Infinite
+    u1_timeout: u8,
+    /// U2 Timeout – RWS. Default = ‘0’. Timeout value for U2 inactivity timer. If equal to FFh, the port
+    /// is disabled from initiating U2 entry. This field shall be set to ‘0’ by the assertion of PR to ‘1’. Refer
+    /// to section 4.19.4.1 for more information on U2 Timeout operation. The following are
+    /// permissible values:
+    ///
+    /// Value Description
+    /// 00h Zero (default)
+    /// 01h 256 μs
+    /// 02h 512 μs
+    /// …
+    /// FEh 65,024 ms
+    /// FFh Infinite
+    ///
+    /// A U2 Inactivity Timeout LMP shall be sent by the xHC to the device connected on this port when
+    /// this field is written. Refer to Sections 8.4.3 and 10.4.2.10 of the USB3 specification for more
+    /// details
+    u2_timeout: u8,
+    /// Force Link PM Accept (FLA) - RW. Default = ‘0’. When this bit is set to ‘1’, the port shall generate
+    /// a Set Link Function LMP with the Force_LinkPM_Accept bit asserted (‘1’). When this bit is cleared
+    /// to ‘0’, the port shall generate a Set Link Function LMP with the Force_LinkPM_Accept bit de-
+    /// asserted (‘0’).
+    /// This flag shall be set to ‘0’ by the assertion of PR to ‘1’ or when CCS = transitions from ‘0’ to ‘1’.
+    /// Writes to this flag have no effect if PP = ‘0’.
+    /// The Set Link Function LMP is sent by the xHC to the device connected on this port when this bit
+    /// transitions from ‘0’ to ‘1’ or ‘1’ to ‘0’. Refer to Sections 8.4.2 and 10.14.2.2 of the USB3
+    /// specification for more details.
+    /// Improper use of the SS Force_LinkPM_Accept functionality can impact the performance of the
+    /// link significantly. This bit shall only be used for compliance and testing purposes. Software shall
+    /// ensure that there are no pending packets at the link level before setting this bit.
+    /// This flag is ‘0’ if PP is ‘0’
+    force_link_pm_accept: bool,
+    #[bits(15)]
+    __: u16,
+}
+
+/// XHCI Spec 5.4.10
+///
+/// NOTE: This definition is USB3 only.
+#[bitfield(u32)]
+pub struct PortLinkInfo {
+    /// Link Error Count – RW. Default = ‘0’. This field returns the number of link errors detected by the
+    /// port. This value shall be reset to ‘0’ by the assertion of a Chip Hardware Reset, HCRST, when PR
+    /// transitions from ‘1’ to ‘0’, or when reset by software by writing 0 to it. This register will increment
+    /// by one each time a port transitions from U0 to Recovery to recover an error event and will
+    /// saturate at max
+    link_error_count: u16,
+    /// Rx Lane Count (RLC) - RO. Default = '0'. This field that identifies the number of Receive Lanes
+    /// negotiated by the port. This is a "zero-based" value, where 0 to 15 represents Lane Counts of 1
+    /// to 16, respectively. This value is valid only when CCS = '1'. RLC shall equal '0' for a simplex
+    /// Sublink. Refer to section 7.2.1 for more information.
+    #[bits(4)]
+    rx_lane_count: u8,
+    /// Tx Lane Count (TLC) - RO. Default = '0'. This field that identifies the number of Transmit Lanes
+    /// negotiated by the port. This is a "zero-based" value, where 0 to 15 represents Lane Counts of 1
+    /// to 16, respectively. This value is valid only when CCS = '1'. TLC shall equal '0' for a simplex
+    /// Sublink. Refer to section 7.2.1 for more information.
+    #[bits(4)]
+    tx_lane_count: u8,
+    __: u8,
+}
+
+/// XHCI Spec 5.4.8 - 5.4.11
+///
+/// These registers are an array of size MAX_PORTS located at offset 0x400
+/// from the HostControllerOperation address.
+///
+/// Where MAX_PORTS is HostControllerCapabilities.params_1.max_ports
+#[repr(C)]
+#[derive(Copy, Clone)]
+pub struct HostControllerUsbPort {
+    pub status_and_control: PortStatusAndControl,
+    pub power_management_status_and_control: PortPowerManagementStatusAndControl,
+    pub link_info: PortLinkInfo,
+    pub hardware_lpm_control: u32,
+}
+
+const _: () = assert!(size_of::<HostControllerUsbPort>() == 0x10);

rust/sys/voyageurs/src/xhci/registers/interrupter.rs

@@ -0,0 +1,165 @@
+use bitfield_struct::bitfield;
+
+use crate::xhci::data_structures::EventRingSegmentTable;
+
+/// The Interrupter Management register allows system software to enable, disable,
+/// and detect xHC interrupts.
+///
+/// XHCI 5.5.2.1
+#[bitfield(u32)]
+pub struct InterrupterManagement {
+    /// Interrupt Pending (IP) - RW1C. Default = ‘0’. This flag represents the current state of the
+    /// Interrupter. If IP = ‘1’, an interrupt is pending for this Interrupter. A ‘0’ value indicates that no
+    /// interrupt is pending for the Interrupter. Refer to section 4.17.3 for the conditions that modify
+    /// the state of this flag.
+    pub interrupt_pending: bool,
+
+    /// Interrupt Enable (IE) – RW. Default = ‘0’. This flag specifies whether the Interrupter is capable of
+    /// generating an interrupt. When this bit and the IP bit are set (‘1’), the Interrupter shall generate
+    /// an interrupt when the Interrupter Moderation Counter reaches ‘0’. If this bit is ‘0’, then the
+    /// Interrupter is prohibited from generating interrupts
+    pub interrupt_enabled: bool,
+
+    #[bits(30)]
+    _reserved: u32,
+}
+
+/// The Interrupter Moderation Register controls the “interrupt moderation” feature
+/// of an Interrupter, allowing system software to throttle the interrupt rate
+/// generated by the xHC
+///
+/// XHCI 5.5.2.2
+#[bitfield(u32)]
+pub struct InterrupterModeration {
+    /// Interrupt Moderation Interval (IMODI) – RW. Default = ‘4000’ (~1ms). Minimum inter-interrupt
+    /// interval. The interval is specified in 250ns increments. A value of ‘0’ disables interrupt throttling
+    /// logic and interrupts shall be generated immediately if IP = ‘0’, EHB = ‘0’, and the Event Ring is
+    /// not empty
+    pub interrupt_moderation_interval: u16,
+
+    /// Interrupt Moderation Counter (IMODC) – RW. Default = undefined. Down counter. Loaded with
+    /// the IMODI value whenever IP is cleared to ‘0’, counts down to ‘0’, and stops. The associated
+    /// interrupt shall be signaled whenever this counter is ‘0’, the Event Ring is not empty, the IE and IP
+    /// flags = ‘1’, and EHB = ‘0’.
+    /// This counter may be directly written by software at any time to alter the interrupt rate
+    pub interrupt_moderation_counter: u16,
+}
+
+/// The Event Ring Segment Table Size Register defines the number of segments
+/// supported by the Event Ring Segment Table.
+///
+/// XHCI 5.5.2.3.1
+#[bitfield(u32)]
+pub struct EventRingSegmentTableSize {
+    pub event_ring_segment_table_size: u16,
+    _reserved: u16,
+}
+
+/// The Event Ring Dequeue Pointer Register is written by software to define the
+/// Event Ring Dequeue Pointer location to the xHC. Software updates this pointer
+/// when it is finished the evaluation of an Event(s) on the Event Ring.
+///
+/// XHCI 5.5.2.3.3
+#[bitfield(u64)]
+pub struct EventRingDequePointer {
+    /// Dequeue ERST Segment Index (DESI) – RW. Default = ‘0’. This field may be used by the xHC to
+    /// accelerate checking the Event Ring full condition. This field is written with the low order 3 bits of
+    /// the offset of the ERST entry which defines the Event Ring segment that the Event Ring Dequeue
+    /// Pointer resides in. Refer to section 6.5 for the definition of an ERST entry.
+    #[bits(3)]
+    pub dequeue_erst_segment_index: u8,
+
+    /// Event Handler Busy (EHB) - RW1C. Default = ‘0’. This flag shall be set to ‘1’ when the IP bit is set
+    /// to ‘1’ and cleared to ‘0’ by software when the Dequeue Pointer register is written. Refer to
+    /// section 4.17.2 for more information
+    pub event_handler_busy: bool,
+
+    /// Event Ring Dequeue Pointer - RW. Default = ‘0’. This field defines the high order bits of the 64-
+    /// bit address of the current Event Ring Dequeue Pointer
+    #[bits(60)]
+    pub event_ring_dequeue_pointer: u64,
+}
+
+/// This is an array of registers starting at offset 0x20 of the Runtime Base.
+/// The Runtime Base shall be 32-byte aligned and is calculated by adding the
+/// value Runtime Register Space Offset register (refer to Section 5.3.8) to
+/// the Capability Base address. All Runtime registers are multiples of 32 bits in length.
+///
+/// XHCI Spec 5.5.2
+#[repr(C, packed)]
+pub struct InterrupterRegisterSet {
+    pub interrupter_management: InterrupterManagement,
+    pub interrupter_moderation: InterrupterModeration,
+    /// Event Ring Segment Table Size – RW. Default = ‘0’. This field identifies the number of valid
+    /// Event Ring Segment Table entries in the Event Ring Segment Table pointed to by the Event Ring
+    /// Segment Table Base Address register. The maximum value supported by an xHC
+    /// implementation for this register is defined by the ERST Max field in the HCSPARAMS2 register
+    /// (5.3.4).
+    /// For Secondary Interrupters: Writing a value of ‘0’ to this field disables the Event Ring. Any events
+    /// targeted at this Event Ring when it is disabled shall result in undefined behavior of the Event
+    /// Ring.
+    /// For the Primary Interrupter: Writing a value of ‘0’ to this field shall result in undefined behavior
+    /// of the Event Ring. The Primary Event Ring cannot be disabled.
+    event_ring_segment_table_size: u32,
+    ___: u32,
+    /// Event Ring Segment Table Base Address Register – RW. Default = ‘0’. This field defines the
+    /// high order bits of the start address of the Event Ring Segment Table.
+    /// Writing this register sets the Event Ring State Machine:EREP Advancement to the Start state.
+    /// Refer to Figure 4-12 for more information.
+    /// For Secondary Interrupters: This field may be modified at any time.
+    /// For the Primary Interrupter: This field shall not be modified if HCHalted (HCH) = ‘0’.
+    ///
+    /// NOTE: This must be aligned such that bits 0:5 are 0.
+    ///
+    /// XHCI 5.5.2.3.2
+    event_ring_segment_table_base_address: u64,
+    event_ring_deque_pointer: u64,
+}
+
+impl InterrupterRegisterSet {
+    /// SAFETY:
+    ///  - For the primary interrupter HC must be halted.
+    ///  - The event rings size must be at most ERST_MAX from HCSPARAMS2
+    pub unsafe fn set_event_ring(
+        &mut self,
+        event_ring_segment_table: &EventRingSegmentTable,
+        event_ring_dequeue_pointer: usize,
+    ) {
+        // NOTE: We must write the size before the base address otherwise qemu is unhappy.
+        // Not sure if this is required by the spec.
+
+        // SAFETY:
+        //   - We know this address is valid and we have a mut reference to it.
+        unsafe {
+            core::ptr::write_volatile(
+                core::ptr::addr_of!(self.event_ring_segment_table_size) as *mut _,
+                event_ring_segment_table.len() as u32,
+            );
+
+            core::ptr::write_volatile(
+                core::ptr::addr_of!(self.event_ring_segment_table_base_address) as *mut _,
+                event_ring_segment_table.physical_address(),
+            );
+
+            core::ptr::write_volatile(
+                core::ptr::addr_of!(self.event_ring_deque_pointer) as *mut _,
+                event_ring_dequeue_pointer,
+            );
+        }
+    }
+
+    pub fn update_dequeue_pointer(&mut self, event_ring_dequeue_pointer: usize) {
+        // SAFETY:
+        //   - We know this address is valid and we have a mut pointer to it.
+        unsafe {
+            // TODO: Preserve lower bits, also update it to make it clear that we
+            // are clearing the EHB bit.
+            core::ptr::write_volatile(
+                core::ptr::addr_of!(self.event_ring_deque_pointer) as *mut _,
+                event_ring_dequeue_pointer | (1 << 3),
+            )
+        }
+    }
+}
+
+const _: () = assert!(size_of::<InterrupterRegisterSet>() == 0x20);

rust/sys/voyageurs/src/xhci/registers/mod.rs

@@ -0,0 +1,15 @@
+/// This mod contains XHCI Register Definitions
+///
+/// These are generally hardware backed registers
+/// defined at fixed addresses.
+mod capabilities;
+mod doorbell;
+mod host_controller;
+mod host_controller_port;
+mod interrupter;
+
+pub use capabilities::*;
+pub use doorbell::*;
+pub use host_controller::*;
+pub use host_controller_port::*;
+pub use interrupter::*;