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// SPDX-License-Identifier: GPL-2.0 //! Abstractions for the PCI bus.//!//! C header: [`include/linux/pci.h`](srctree/include/linux/pci.h) use crate::{    bindings,    container_of,    device,    device_id::{        RawDeviceId,        RawDeviceIdIndex, //    },    driver,    error::{        from_result,        to_result, //    },    prelude::*,    str::CStr,    types::Opaque,    ThisModule, //};use core::{    marker::PhantomData,    mem::offset_of,    ptr::{        addr_of_mut,        NonNull, //    },}; mod id;mod io;mod irq; pub use self::id::{    Class,    ClassMask,    Vendor, //};pub use self::io::{    Bar,    ConfigSpace,    ConfigSpaceKind,    ConfigSpaceSize,    Extended,    Normal, //};pub use self::irq::{    IrqType,    IrqTypes,    IrqVector, //}; /// An adapter for the registration of PCI drivers.pub struct Adapter<T: Driver>(T); // SAFETY:// - `bindings::pci_driver` is a C type declared as `repr(C)`.// - `T::Data` is the type of the driver's device private data.// - `struct pci_driver` embeds a `struct device_driver`.// - `DEVICE_DRIVER_OFFSET` is the correct byte offset to the embedded `struct device_driver`.unsafe impl<T: Driver> driver::DriverLayout for Adapter<T> {    type DriverType = bindings::pci_driver;    type DriverData<'bound> = T::Data<'bound>;    const DEVICE_DRIVER_OFFSET: usize = core::mem::offset_of!(Self::DriverType, driver);} // SAFETY: A call to `unregister` for a given instance of `DriverType` is guaranteed to be valid if// a preceding call to `register` has been successful.unsafe impl<T: Driver> driver::RegistrationOps for Adapter<T> {    unsafe fn register(        pdrv: &Opaque<Self::DriverType>,        name: &'static CStr,        module: &'static ThisModule,    ) -> Result {        // SAFETY: It's safe to set the fields of `struct pci_driver` on initialization.        unsafe {            (*pdrv.get()).name = name.as_char_ptr();            (*pdrv.get()).probe = Some(Self::probe_callback);            (*pdrv.get()).remove = Some(Self::remove_callback);            (*pdrv.get()).id_table = T::ID_TABLE.as_ptr();        }         // SAFETY: `pdrv` is guaranteed to be a valid `DriverType`.        to_result(unsafe {            bindings::__pci_register_driver(pdrv.get(), module.0, name.as_char_ptr())        })    }     unsafe fn unregister(pdrv: &Opaque<Self::DriverType>) {        // SAFETY: `pdrv` is guaranteed to be a valid `DriverType`.        unsafe { bindings::pci_unregister_driver(pdrv.get()) }    }} impl<T: Driver> Adapter<T> {    extern "C" fn probe_callback(        pdev: *mut bindings::pci_dev,        id: *const bindings::pci_device_id,    ) -> c_int {        // SAFETY: The PCI bus only ever calls the probe callback with a valid pointer to a        // `struct pci_dev`.        //        // INVARIANT: `pdev` is valid for the duration of `probe_callback()`.        let pdev = unsafe { &*pdev.cast::<Device<device::CoreInternal<'_>>>() };         // SAFETY: `DeviceId` is a `#[repr(transparent)]` wrapper of `struct pci_device_id` and        // does not add additional invariants, so it's safe to transmute.        let id = unsafe { &*id.cast::<DeviceId>() };        let info = T::ID_TABLE.info(id.index());         from_result(|| {            let data = T::probe(pdev, info);             pdev.as_ref().set_drvdata(data)?;            Ok(0)        })    }     extern "C" fn remove_callback(pdev: *mut bindings::pci_dev) {        // SAFETY: The PCI bus only ever calls the remove callback with a valid pointer to a        // `struct pci_dev`.        //        // INVARIANT: `pdev` is valid for the duration of `remove_callback()`.        let pdev = unsafe { &*pdev.cast::<Device<device::CoreInternal<'_>>>() };         // SAFETY: `remove_callback` is only ever called after a successful call to        // `probe_callback`, hence it's guaranteed that `Device::set_drvdata()` has been called        // and stored a `Pin<KBox<T::Data<'_>>>`.        let data = unsafe { pdev.as_ref().drvdata_borrow::<T::Data<'_>>() };         T::unbind(pdev, data);    }} /// Declares a kernel module that exposes a single PCI driver.////// # Examples//////```ignore/// kernel::module_pci_driver! {///     type: MyDriver,///     name: "Module name",///     authors: ["Author name"],///     description: "Description",///     license: "GPL v2",/// }///```#[macro_export]macro_rules! module_pci_driver {($($f:tt)*) => {    $crate::module_driver!(<T>, $crate::pci::Adapter<T>, { $($f)* });};} /// Abstraction for the PCI device ID structure ([`struct pci_device_id`]).////// [`struct pci_device_id`]: https://docs.kernel.org/PCI/pci.html#c.pci_device_id#[repr(transparent)]#[derive(Clone, Copy)]pub struct DeviceId(bindings::pci_device_id); impl DeviceId {    const PCI_ANY_ID: u32 = !0;     /// Equivalent to C's `PCI_DEVICE` macro.    ///    /// Create a new `pci::DeviceId` from a vendor and device ID.    #[inline]    pub const fn from_id(vendor: Vendor, device: u32) -> Self {        Self(bindings::pci_device_id {            vendor: vendor.as_raw() as u32,            device,            subvendor: DeviceId::PCI_ANY_ID,            subdevice: DeviceId::PCI_ANY_ID,            class: 0,            class_mask: 0,            driver_data: 0,            override_only: 0,        })    }     /// Equivalent to C's `PCI_DEVICE_CLASS` macro.    ///    /// Create a new `pci::DeviceId` from a class number and mask.    #[inline]    pub const fn from_class(class: u32, class_mask: u32) -> Self {        Self(bindings::pci_device_id {            vendor: DeviceId::PCI_ANY_ID,            device: DeviceId::PCI_ANY_ID,            subvendor: DeviceId::PCI_ANY_ID,            subdevice: DeviceId::PCI_ANY_ID,            class,            class_mask,            driver_data: 0,            override_only: 0,        })    }     /// Create a new [`DeviceId`] from a class number, mask, and specific vendor.    ///    /// This is more targeted than [`DeviceId::from_class`]: in addition to matching by [`Vendor`],    /// it also matches the PCI [`Class`] (up to the entire 24 bits, depending on the    /// [`ClassMask`]).    #[inline]    pub const fn from_class_and_vendor(        class: Class,        class_mask: ClassMask,        vendor: Vendor,    ) -> Self {        Self(bindings::pci_device_id {            vendor: vendor.as_raw() as u32,            device: DeviceId::PCI_ANY_ID,            subvendor: DeviceId::PCI_ANY_ID,            subdevice: DeviceId::PCI_ANY_ID,            class: class.as_raw(),            class_mask: class_mask.as_raw(),            driver_data: 0,            override_only: 0,        })    }} // SAFETY: `DeviceId` is a `#[repr(transparent)]` wrapper of `pci_device_id` and does not add// additional invariants, so it's safe to transmute to `RawType`.unsafe impl RawDeviceId for DeviceId {    type RawType = bindings::pci_device_id;} // SAFETY: `DRIVER_DATA_OFFSET` is the offset to the `driver_data` field.unsafe impl RawDeviceIdIndex for DeviceId {    const DRIVER_DATA_OFFSET: usize = core::mem::offset_of!(bindings::pci_device_id, driver_data);     fn index(&self) -> usize {        self.0.driver_data    }} /// `IdTable` type for PCI.pub type IdTable<T> = &'static dyn kernel::device_id::IdTable<DeviceId, T>; /// Create a PCI `IdTable` with its alias for modpost.#[macro_export]macro_rules! pci_device_table {    ($table_name:ident, $module_table_name:ident, $id_info_type: ty, $table_data: expr) => {        const $table_name: $crate::device_id::IdArray<            $crate::pci::DeviceId,            $id_info_type,            { $table_data.len() },        > = $crate::device_id::IdArray::new($table_data);         $crate::module_device_table!("pci", $module_table_name, $table_name);    };} /// The PCI driver trait.////// # Examples//////```/// # use kernel::{bindings, device::Core, pci};////// struct MyDriver;////// kernel::pci_device_table!(///     PCI_TABLE,///     MODULE_PCI_TABLE,///     <MyDriver as pci::Driver>::IdInfo,///     [///         (///             pci::DeviceId::from_id(pci::Vendor::REDHAT, bindings::PCI_ANY_ID as u32),///             (),///         )///     ]/// );////// impl pci::Driver for MyDriver {///     type IdInfo = ();///     type Data<'bound> = Self;///     const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;//////     fn probe<'bound>(///         _pdev: &'bound pci::Device<Core<'_>>,///         _id_info: &'bound Self::IdInfo,///     ) -> impl PinInit<Self::Data<'bound>, Error> + 'bound {///         Err(ENODEV)///     }/// }///```/// Drivers must implement this trait in order to get a PCI driver registered. Please refer to the/// `Adapter` documentation for an example.pub trait Driver {    /// The type holding information about each device id supported by the driver.    // TODO: Use `associated_type_defaults` once stabilized:    //    // ```    // type IdInfo: 'static = ();    // ```    type IdInfo: 'static;     /// The type of the driver's bus device private data.    type Data<'bound>: Send + 'bound;     /// The table of device ids supported by the driver.    const ID_TABLE: IdTable<Self::IdInfo>;     /// PCI driver probe.    ///    /// Called when a new pci device is added or discovered. Implementers should    /// attempt to initialize the device here.    fn probe<'bound>(        dev: &'bound Device<device::Core<'_>>,        id_info: &'bound Self::IdInfo,    ) -> impl PinInit<Self::Data<'bound>, Error> + 'bound;     /// PCI driver unbind.    ///    /// Called when a [`Device`] is unbound from its bound [`Driver`]. Implementing this callback    /// is optional.    ///    /// This callback serves as a place for drivers to perform teardown operations that require a    /// `&Device<Core>` or `&Device<Bound>` reference. For instance, drivers may try to perform I/O    /// operations to gracefully tear down the device.    ///    /// Otherwise, release operations for driver resources should be performed in `Drop`.    fn unbind<'bound>(dev: &'bound Device<device::Core<'_>>, this: Pin<&Self::Data<'bound>>) {        let _ = (dev, this);    }} /// The PCI device representation.////// This structure represents the Rust abstraction for a C `struct pci_dev`. The implementation/// abstracts the usage of an already existing C `struct pci_dev` within Rust code that we get/// passed from the C side.////// # Invariants////// A [`Device`] instance represents a valid `struct pci_dev` created by the C portion of the/// kernel.#[repr(transparent)]pub struct Device<Ctx: device::DeviceContext = device::Normal>(    Opaque<bindings::pci_dev>,    PhantomData<Ctx>,); impl<Ctx: device::DeviceContext> Device<Ctx> {    #[inline]    fn as_raw(&self) -> *mut bindings::pci_dev {        self.0.get()    }} impl Device {    /// Returns the PCI vendor ID as [`Vendor`].    ///    /// # Examples    ///    /// ```    /// # use kernel::{device::Core, pci::{self, Vendor}, prelude::*};    /// fn log_device_info(pdev: &pci::Device<Core<'_>>) -> Result {    ///     // Get an instance of `Vendor`.    ///     let vendor = pdev.vendor_id();    ///     dev_info!(    ///         pdev,    ///         "Device: Vendor={}, Device=0x{:x}\n",    ///         vendor,    ///         pdev.device_id()    ///     );    ///     Ok(())    /// }    /// ```    #[inline]    pub fn vendor_id(&self) -> Vendor {        // SAFETY: `self.as_raw` is a valid pointer to a `struct pci_dev`.        let vendor_id = unsafe { (*self.as_raw()).vendor };        Vendor::from_raw(vendor_id)    }     /// Returns the PCI device ID.    #[inline]    pub fn device_id(&self) -> u16 {        // SAFETY: By its type invariant `self.as_raw` is always a valid pointer to a        // `struct pci_dev`.        unsafe { (*self.as_raw()).device }    }     /// Returns the PCI revision ID.    #[inline]    pub fn revision_id(&self) -> u8 {        // SAFETY: By its type invariant `self.as_raw` is always a valid pointer to a        // `struct pci_dev`.        unsafe { (*self.as_raw()).revision }    }     /// Returns the PCI bus device/function.    #[inline]    pub fn dev_id(&self) -> u16 {        // SAFETY: By its type invariant `self.as_raw` is always a valid pointer to a        // `struct pci_dev`.        unsafe { bindings::pci_dev_id(self.as_raw()) }    }     /// Returns the PCI subsystem vendor ID.    #[inline]    pub fn subsystem_vendor_id(&self) -> u16 {        // SAFETY: By its type invariant `self.as_raw` is always a valid pointer to a        // `struct pci_dev`.        unsafe { (*self.as_raw()).subsystem_vendor }    }     /// Returns the PCI subsystem device ID.    #[inline]    pub fn subsystem_device_id(&self) -> u16 {        // SAFETY: By its type invariant `self.as_raw` is always a valid pointer to a        // `struct pci_dev`.        unsafe { (*self.as_raw()).subsystem_device }    }     /// Returns the start of the given PCI BAR resource.    pub fn resource_start(&self, bar: u32) -> Result<bindings::resource_size_t> {        if !Bar::index_is_valid(bar) {            return Err(EINVAL);        }         // SAFETY:        // - `bar` is a valid bar number, as guaranteed by the above call to `Bar::index_is_valid`,        // - by its type invariant `self.as_raw` is always a valid pointer to a `struct pci_dev`.        Ok(unsafe { bindings::pci_resource_start(self.as_raw(), bar.try_into()?) })    }     /// Returns the size of the given PCI BAR resource.    pub fn resource_len(&self, bar: u32) -> Result<bindings::resource_size_t> {        if !Bar::index_is_valid(bar) {            return Err(EINVAL);        }         // SAFETY:        // - `bar` is a valid bar number, as guaranteed by the above call to `Bar::index_is_valid`,        // - by its type invariant `self.as_raw` is always a valid pointer to a `struct pci_dev`.        Ok(unsafe { bindings::pci_resource_len(self.as_raw(), bar.try_into()?) })    }     /// Returns the PCI class as a `Class` struct.    #[inline]    pub fn pci_class(&self) -> Class {        // SAFETY: `self.as_raw` is a valid pointer to a `struct pci_dev`.        Class::from_raw(unsafe { (*self.as_raw()).class })    }} impl<'a> Device<device::Core<'a>> {    /// Enable memory resources for this device.    pub fn enable_device_mem(&self) -> Result {        // SAFETY: `self.as_raw` is guaranteed to be a pointer to a valid `struct pci_dev`.        to_result(unsafe { bindings::pci_enable_device_mem(self.as_raw()) })    }     /// Enable bus-mastering for this device.    #[inline]    pub fn set_master(&self) {        // SAFETY: `self.as_raw` is guaranteed to be a pointer to a valid `struct pci_dev`.        unsafe { bindings::pci_set_master(self.as_raw()) };    }} // SAFETY: `pci::Device` is a transparent wrapper of `struct pci_dev`.// The offset is guaranteed to point to a valid device field inside `pci::Device`.unsafe impl<Ctx: device::DeviceContext> device::AsBusDevice<Ctx> for Device<Ctx> {    const OFFSET: usize = offset_of!(bindings::pci_dev, dev);} // SAFETY: `Device` is a transparent wrapper of a type that doesn't depend on `Device`'s generic// argument.kernel::impl_device_context_deref!(unsafe { Device });kernel::impl_device_context_into_aref!(Device); impl<'a> crate::dma::Device<'a> for Device<device::Core<'a>> {} // SAFETY: Instances of `Device` are always reference-counted.unsafe impl crate::sync::aref::AlwaysRefCounted for Device {    fn inc_ref(&self) {        // SAFETY: The existence of a shared reference guarantees that the refcount is non-zero.        unsafe { bindings::pci_dev_get(self.as_raw()) };    }     unsafe fn dec_ref(obj: NonNull<Self>) {        // SAFETY: The safety requirements guarantee that the refcount is non-zero.        unsafe { bindings::pci_dev_put(obj.cast().as_ptr()) }    }} impl<Ctx: device::DeviceContext> AsRef<device::Device<Ctx>> for Device<Ctx> {    fn as_ref(&self) -> &device::Device<Ctx> {        // SAFETY: By the type invariant of `Self`, `self.as_raw()` is a pointer to a valid        // `struct pci_dev`.        let dev = unsafe { addr_of_mut!((*self.as_raw()).dev) };

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