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-rw-r--r--rust/kernel/pci.rs168
1 files changed, 100 insertions, 68 deletions
diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
index c97d6d470b28..887ee611b553 100644
--- a/rust/kernel/pci.rs
+++ b/rust/kernel/pci.rs
@@ -5,16 +5,15 @@
//! C header: [`include/linux/pci.h`](srctree/include/linux/pci.h)
use crate::{
- alloc::flags::*,
- bindings, device,
- device_id::RawDeviceId,
+ bindings, container_of, device,
+ device_id::{RawDeviceId, RawDeviceIdIndex},
devres::Devres,
driver,
- error::{to_result, Result},
+ error::{from_result, to_result, Result},
io::Io,
io::IoRaw,
str::CStr,
- types::{ARef, ForeignOwnable, Opaque},
+ types::{ARef, Opaque},
ThisModule,
};
use core::{
@@ -66,41 +65,40 @@ impl<T: Driver + 'static> Adapter<T> {
// `struct pci_dev`.
//
// INVARIANT: `pdev` is valid for the duration of `probe_callback()`.
- let pdev = unsafe { &*pdev.cast::<Device<device::Core>>() };
+ let pdev = unsafe { &*pdev.cast::<Device<device::CoreInternal>>() };
- // SAFETY: `DeviceId` is a `#[repr(transparent)` wrapper of `struct pci_device_id` and
+ // 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());
- match T::probe(pdev, info) {
- Ok(data) => {
- // Let the `struct pci_dev` own a reference of the driver's private data.
- // SAFETY: By the type invariant `pdev.as_raw` returns a valid pointer to a
- // `struct pci_dev`.
- unsafe { bindings::pci_set_drvdata(pdev.as_raw(), data.into_foreign() as _) };
- }
- Err(err) => return Error::to_errno(err),
- }
+ from_result(|| {
+ let data = T::probe(pdev, info)?;
- 0
+ 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`.
- let ptr = unsafe { bindings::pci_get_drvdata(pdev) };
+ //
+ // 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 `ptr` points to a valid and initialized
- // `KBox<T>` pointer created through `KBox::into_foreign`.
- let _ = unsafe { KBox::<T>::from_foreign(ptr) };
+ // `probe_callback`, hence it's guaranteed that `Device::set_drvdata()` has been called
+ // and stored a `Pin<KBox<T>>`.
+ let data = unsafe { pdev.as_ref().drvdata_obtain::<Pin<KBox<T>>>() };
+
+ T::unbind(pdev, data.as_ref());
}
}
/// Declares a kernel module that exposes a single PCI driver.
///
-/// # Example
+/// # Examples
///
///```ignore
/// kernel::module_pci_driver! {
@@ -118,7 +116,9 @@ macro_rules! module_pci_driver {
};
}
-/// Abstraction for bindings::pci_device_id.
+/// 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);
@@ -159,21 +159,22 @@ impl DeviceId {
}
}
-// 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`.
-// * `DRIVER_DATA_OFFSET` is the offset to the `driver_data` field.
+// 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 as _
+ self.0.driver_data
}
}
-/// IdTable type for PCI
+/// `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.
@@ -192,7 +193,7 @@ macro_rules! pci_device_table {
/// The PCI driver trait.
///
-/// # Example
+/// # Examples
///
///```
/// # use kernel::{bindings, device::Core, pci};
@@ -204,7 +205,10 @@ macro_rules! pci_device_table {
/// MODULE_PCI_TABLE,
/// <MyDriver as pci::Driver>::IdInfo,
/// [
-/// (pci::DeviceId::from_id(bindings::PCI_VENDOR_ID_REDHAT, bindings::PCI_ANY_ID as _), ())
+/// (
+/// pci::DeviceId::from_id(bindings::PCI_VENDOR_ID_REDHAT, bindings::PCI_ANY_ID as u32),
+/// (),
+/// )
/// ]
/// );
///
@@ -224,10 +228,11 @@ macro_rules! pci_device_table {
/// `Adapter` documentation for an example.
pub trait Driver: Send {
/// The type holding information about each device id supported by the driver.
- ///
- /// TODO: Use associated_type_defaults once stabilized:
- ///
- /// type IdInfo: 'static = ();
+ // TODO: Use `associated_type_defaults` once stabilized:
+ //
+ // ```
+ // type IdInfo: 'static = ();
+ // ```
type IdInfo: 'static;
/// The table of device ids supported by the driver.
@@ -238,6 +243,20 @@ pub trait Driver: Send {
/// Called when a new platform device is added or discovered.
/// Implementers should attempt to initialize the device here.
fn probe(dev: &Device<device::Core>, id_info: &Self::IdInfo) -> Result<Pin<KBox<Self>>>;
+
+ /// Platform 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 `Self::drop`.
+ fn unbind(dev: &Device<device::Core>, this: Pin<&Self>) {
+ let _ = (dev, this);
+ }
}
/// The PCI device representation.
@@ -248,7 +267,8 @@ pub trait Driver: Send {
///
/// # Invariants
///
-/// A [`Device`] instance represents a valid `struct device` created by the C portion of the kernel.
+/// 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>,
@@ -327,7 +347,7 @@ impl<const SIZE: usize> Bar<SIZE> {
// `ioptr` is valid by the safety requirements.
// `num` is valid by the safety requirements.
unsafe {
- bindings::pci_iounmap(pdev.as_raw(), ioptr as _);
+ bindings::pci_iounmap(pdev.as_raw(), ioptr as *mut kernel::ffi::c_void);
bindings::pci_release_region(pdev.as_raw(), num);
}
}
@@ -360,11 +380,13 @@ impl<const SIZE: usize> Deref for Bar<SIZE> {
}
}
-impl Device {
+impl<Ctx: device::DeviceContext> Device<Ctx> {
fn as_raw(&self) -> *mut bindings::pci_dev {
self.0.get()
}
+}
+impl Device {
/// Returns the PCI vendor ID.
pub fn vendor_id(&self) -> u16 {
// SAFETY: `self.as_raw` is a valid pointer to a `struct pci_dev`.
@@ -388,22 +410,25 @@ impl Device {
// - 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()?) })
}
+}
+impl Device<device::Bound> {
/// Mapps an entire PCI-BAR after performing a region-request on it. I/O operation bound checks
/// can be performed on compile time for offsets (plus the requested type size) < SIZE.
- pub fn iomap_region_sized<const SIZE: usize>(
- &self,
+ pub fn iomap_region_sized<'a, const SIZE: usize>(
+ &'a self,
bar: u32,
- name: &CStr,
- ) -> Result<Devres<Bar<SIZE>>> {
- let bar = Bar::<SIZE>::new(self, bar, name)?;
- let devres = Devres::new(self.as_ref(), bar, GFP_KERNEL)?;
-
- Ok(devres)
+ name: &'a CStr,
+ ) -> impl PinInit<Devres<Bar<SIZE>>, Error> + 'a {
+ Devres::new(self.as_ref(), Bar::<SIZE>::new(self, bar, name))
}
/// Mapps an entire PCI-BAR after performing a region-request on it.
- pub fn iomap_region(&self, bar: u32, name: &CStr) -> Result<Devres<Bar>> {
+ pub fn iomap_region<'a>(
+ &'a self,
+ bar: u32,
+ name: &'a CStr,
+ ) -> impl PinInit<Devres<Bar>, Error> + 'a {
self.iomap_region_sized::<0>(bar, name)
}
}
@@ -422,25 +447,12 @@ impl Device<device::Core> {
}
}
-impl Deref for Device<device::Core> {
- type Target = Device;
-
- fn deref(&self) -> &Self::Target {
- let ptr: *const Self = self;
-
- // CAST: `Device<Ctx>` is a transparent wrapper of `Opaque<bindings::pci_dev>`.
- let ptr = ptr.cast::<Device>();
+// 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);
- // SAFETY: `ptr` was derived from `&self`.
- unsafe { &*ptr }
- }
-}
-
-impl From<&Device<device::Core>> for ARef<Device> {
- fn from(dev: &Device<device::Core>) -> Self {
- (&**dev).into()
- }
-}
+impl crate::dma::Device for Device<device::Core> {}
// SAFETY: Instances of `Device` are always reference-counted.
unsafe impl crate::types::AlwaysRefCounted for Device {
@@ -455,14 +467,34 @@ unsafe impl crate::types::AlwaysRefCounted for Device {
}
}
-impl AsRef<device::Device> for Device {
- fn as_ref(&self) -> &device::Device {
+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) };
// SAFETY: `dev` points to a valid `struct device`.
- unsafe { device::Device::as_ref(dev) }
+ unsafe { device::Device::from_raw(dev) }
+ }
+}
+
+impl<Ctx: device::DeviceContext> TryFrom<&device::Device<Ctx>> for &Device<Ctx> {
+ type Error = kernel::error::Error;
+
+ fn try_from(dev: &device::Device<Ctx>) -> Result<Self, Self::Error> {
+ // SAFETY: By the type invariant of `Device`, `dev.as_raw()` is a valid pointer to a
+ // `struct device`.
+ if !unsafe { bindings::dev_is_pci(dev.as_raw()) } {
+ return Err(EINVAL);
+ }
+
+ // SAFETY: We've just verified that the bus type of `dev` equals `bindings::pci_bus_type`,
+ // hence `dev` must be embedded in a valid `struct pci_dev` as guaranteed by the
+ // corresponding C code.
+ let pdev = unsafe { container_of!(dev.as_raw(), bindings::pci_dev, dev) };
+
+ // SAFETY: `pdev` is a valid pointer to a `struct pci_dev`.
+ Ok(unsafe { &*pdev.cast() })
}
}
generated by cgit v1.2.3 (git 2.46.0) at 2025-08-05 11:59:57 +0000