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-rw-r--r--rust/kernel/platform.rs437
1 files changed, 378 insertions, 59 deletions
diff --git a/rust/kernel/platform.rs b/rust/kernel/platform.rs
index 50e6b0421813..7205fe3416d3 100644
--- a/rust/kernel/platform.rs
+++ b/rust/kernel/platform.rs
@@ -5,16 +5,22 @@
//! C header: [`include/linux/platform_device.h`](srctree/include/linux/platform_device.h)
use crate::{
- bindings, container_of, device, driver,
- error::{to_result, Result},
+ acpi, bindings, container_of,
+ device::{self, Bound},
+ driver,
+ error::{from_result, to_result, Result},
+ io::{mem::IoRequest, Resource},
+ irq::{self, IrqRequest},
of,
prelude::*,
- str::CStr,
- types::{ARef, ForeignOwnable, Opaque},
+ types::Opaque,
ThisModule,
};
-use core::ptr::addr_of_mut;
+use core::{
+ marker::PhantomData,
+ ptr::{addr_of_mut, NonNull},
+};
/// An adapter for the registration of platform drivers.
pub struct Adapter<T: Driver>(T);
@@ -34,12 +40,18 @@ unsafe impl<T: Driver + 'static> driver::RegistrationOps for Adapter<T> {
None => core::ptr::null(),
};
+ let acpi_table = match T::ACPI_ID_TABLE {
+ Some(table) => table.as_ptr(),
+ None => core::ptr::null(),
+ };
+
// SAFETY: It's safe to set the fields of `struct platform_driver` on initialization.
unsafe {
(*pdrv.get()).driver.name = name.as_char_ptr();
(*pdrv.get()).probe = Some(Self::probe_callback);
(*pdrv.get()).remove = Some(Self::remove_callback);
(*pdrv.get()).driver.of_match_table = of_table;
+ (*pdrv.get()).driver.acpi_match_table = acpi_table;
}
// SAFETY: `pdrv` is guaranteed to be a valid `RegType`.
@@ -54,34 +66,34 @@ unsafe impl<T: Driver + 'static> driver::RegistrationOps for Adapter<T> {
impl<T: Driver + 'static> Adapter<T> {
extern "C" fn probe_callback(pdev: *mut bindings::platform_device) -> kernel::ffi::c_int {
- // SAFETY: The platform bus only ever calls the probe callback with a valid `pdev`.
- let dev = unsafe { device::Device::get_device(addr_of_mut!((*pdev).dev)) };
- // SAFETY: `dev` is guaranteed to be embedded in a valid `struct platform_device` by the
- // call above.
- let mut pdev = unsafe { Device::from_dev(dev) };
-
+ // SAFETY: The platform bus only ever calls the probe callback with a valid pointer to a
+ // `struct platform_device`.
+ //
+ // INVARIANT: `pdev` is valid for the duration of `probe_callback()`.
+ let pdev = unsafe { &*pdev.cast::<Device<device::CoreInternal>>() };
let info = <Self as driver::Adapter>::id_info(pdev.as_ref());
- match T::probe(&mut pdev, info) {
- Ok(data) => {
- // Let the `struct platform_device` own a reference of the driver's private data.
- // SAFETY: By the type invariant `pdev.as_raw` returns a valid pointer to a
- // `struct platform_device`.
- unsafe { bindings::platform_set_drvdata(pdev.as_raw(), data.into_foreign() as _) };
- }
- Err(err) => return Error::to_errno(err),
- }
- 0
+ from_result(|| {
+ let data = T::probe(pdev, info)?;
+
+ pdev.as_ref().set_drvdata(data);
+ Ok(0)
+ })
}
extern "C" fn remove_callback(pdev: *mut bindings::platform_device) {
- // SAFETY: `pdev` is a valid pointer to a `struct platform_device`.
- let ptr = unsafe { bindings::platform_get_drvdata(pdev) };
+ // SAFETY: The platform bus only ever calls the remove callback with a valid pointer to a
+ // `struct platform_device`.
+ //
+ // INVARIANT: `pdev` is valid for the duration of `probe_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());
}
}
@@ -91,6 +103,10 @@ impl<T: Driver + 'static> driver::Adapter for Adapter<T> {
fn of_id_table() -> Option<of::IdTable<Self::IdInfo>> {
T::OF_ID_TABLE
}
+
+ fn acpi_id_table() -> Option<acpi::IdTable<Self::IdInfo>> {
+ T::ACPI_ID_TABLE
+ }
}
/// Declares a kernel module that exposes a single platform driver.
@@ -101,7 +117,7 @@ impl<T: Driver + 'static> driver::Adapter for Adapter<T> {
/// kernel::module_platform_driver! {
/// type: MyDriver,
/// name: "Module name",
-/// author: "Author name",
+/// authors: ["Author name"],
/// description: "Description",
/// license: "GPL v2",
/// }
@@ -117,10 +133,10 @@ macro_rules! module_platform_driver {
///
/// Drivers must implement this trait in order to get a platform driver registered.
///
-/// # Example
+/// # Examples
///
///```
-/// # use kernel::{bindings, c_str, of, platform};
+/// # use kernel::{acpi, bindings, c_str, device::Core, of, platform};
///
/// struct MyDriver;
///
@@ -133,68 +149,371 @@ macro_rules! module_platform_driver {
/// ]
/// );
///
+/// kernel::acpi_device_table!(
+/// ACPI_TABLE,
+/// MODULE_ACPI_TABLE,
+/// <MyDriver as platform::Driver>::IdInfo,
+/// [
+/// (acpi::DeviceId::new(c_str!("LNUXBEEF")), ())
+/// ]
+/// );
+///
/// impl platform::Driver for MyDriver {
/// type IdInfo = ();
/// const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = Some(&OF_TABLE);
+/// const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = Some(&ACPI_TABLE);
///
/// fn probe(
-/// _pdev: &mut platform::Device,
+/// _pdev: &platform::Device<Core>,
/// _id_info: Option<&Self::IdInfo>,
/// ) -> Result<Pin<KBox<Self>>> {
/// Err(ENODEV)
/// }
/// }
///```
-pub trait Driver {
+pub trait Driver: Send {
/// The type holding driver private data 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 OF device ids supported by the driver.
- const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>>;
+ const OF_ID_TABLE: Option<of::IdTable<Self::IdInfo>> = None;
+
+ /// The table of ACPI device ids supported by the driver.
+ const ACPI_ID_TABLE: Option<acpi::IdTable<Self::IdInfo>> = None;
/// Platform driver probe.
///
/// Called when a new platform device is added or discovered.
/// Implementers should attempt to initialize the device here.
- fn probe(dev: &mut Device, id_info: Option<&Self::IdInfo>) -> Result<Pin<KBox<Self>>>;
+ fn probe(dev: &Device<device::Core>, id_info: Option<&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 platform device representation.
///
-/// A platform device is based on an always reference counted `device:Device` instance. Cloning a
-/// platform device, hence, also increments the base device' reference count.
+/// This structure represents the Rust abstraction for a C `struct platform_device`. The
+/// implementation abstracts the usage of an already existing C `struct platform_device` within Rust
+/// code that we get passed from the C side.
///
/// # Invariants
///
-/// `Device` holds a valid reference of `ARef<device::Device>` whose underlying `struct device` is a
-/// member of a `struct platform_device`.
-#[derive(Clone)]
-pub struct Device(ARef<device::Device>);
+/// A [`Device`] instance represents a valid `struct platform_device` created by the C portion of
+/// the kernel.
+#[repr(transparent)]
+pub struct Device<Ctx: device::DeviceContext = device::Normal>(
+ Opaque<bindings::platform_device>,
+ PhantomData<Ctx>,
+);
-impl Device {
- /// Convert a raw kernel device into a `Device`
- ///
- /// # Safety
- ///
- /// `dev` must be an `Aref<device::Device>` whose underlying `bindings::device` is a member of a
- /// `bindings::platform_device`.
- unsafe fn from_dev(dev: ARef<device::Device>) -> Self {
- Self(dev)
+impl<Ctx: device::DeviceContext> Device<Ctx> {
+ fn as_raw(&self) -> *mut bindings::platform_device {
+ self.0.get()
}
- fn as_raw(&self) -> *mut bindings::platform_device {
- // SAFETY: By the type invariant `self.0.as_raw` is a pointer to the `struct device`
- // embedded in `struct platform_device`.
- unsafe { container_of!(self.0.as_raw(), bindings::platform_device, dev) }.cast_mut()
+ /// Returns the resource at `index`, if any.
+ pub fn resource_by_index(&self, index: u32) -> Option<&Resource> {
+ // SAFETY: `self.as_raw()` returns a valid pointer to a `struct platform_device`.
+ let resource = unsafe {
+ bindings::platform_get_resource(self.as_raw(), bindings::IORESOURCE_MEM, index)
+ };
+
+ if resource.is_null() {
+ return None;
+ }
+
+ // SAFETY: `resource` is a valid pointer to a `struct resource` as
+ // returned by `platform_get_resource`.
+ Some(unsafe { Resource::from_raw(resource) })
+ }
+
+ /// Returns the resource with a given `name`, if any.
+ pub fn resource_by_name(&self, name: &CStr) -> Option<&Resource> {
+ // SAFETY: `self.as_raw()` returns a valid pointer to a `struct
+ // platform_device` and `name` points to a valid C string.
+ let resource = unsafe {
+ bindings::platform_get_resource_byname(
+ self.as_raw(),
+ bindings::IORESOURCE_MEM,
+ name.as_char_ptr(),
+ )
+ };
+
+ if resource.is_null() {
+ return None;
+ }
+
+ // SAFETY: `resource` is a valid pointer to a `struct resource` as
+ // returned by `platform_get_resource`.
+ Some(unsafe { Resource::from_raw(resource) })
}
}
-impl AsRef<device::Device> for Device {
- fn as_ref(&self) -> &device::Device {
- &self.0
+impl Device<Bound> {
+ /// Returns an `IoRequest` for the resource at `index`, if any.
+ pub fn io_request_by_index(&self, index: u32) -> Option<IoRequest<'_>> {
+ self.resource_by_index(index)
+ // SAFETY: `resource` is a valid resource for `&self` during the
+ // lifetime of the `IoRequest`.
+ .map(|resource| unsafe { IoRequest::new(self.as_ref(), resource) })
}
+
+ /// Returns an `IoRequest` for the resource with a given `name`, if any.
+ pub fn io_request_by_name(&self, name: &CStr) -> Option<IoRequest<'_>> {
+ self.resource_by_name(name)
+ // SAFETY: `resource` is a valid resource for `&self` during the
+ // lifetime of the `IoRequest`.
+ .map(|resource| unsafe { IoRequest::new(self.as_ref(), resource) })
+ }
+}
+
+macro_rules! define_irq_accessor_by_index {
+ (
+ $(#[$meta:meta])* $fn_name:ident,
+ $request_fn:ident,
+ $reg_type:ident,
+ $handler_trait:ident
+ ) => {
+ $(#[$meta])*
+ pub fn $fn_name<'a, T: irq::$handler_trait + 'static>(
+ &'a self,
+ flags: irq::Flags,
+ index: u32,
+ name: &'static CStr,
+ handler: impl PinInit<T, Error> + 'a,
+ ) -> Result<impl PinInit<irq::$reg_type<T>, Error> + 'a> {
+ let request = self.$request_fn(index)?;
+
+ Ok(irq::$reg_type::<T>::new(
+ request,
+ flags,
+ name,
+ handler,
+ ))
+ }
+ };
}
+
+macro_rules! define_irq_accessor_by_name {
+ (
+ $(#[$meta:meta])* $fn_name:ident,
+ $request_fn:ident,
+ $reg_type:ident,
+ $handler_trait:ident
+ ) => {
+ $(#[$meta])*
+ pub fn $fn_name<'a, T: irq::$handler_trait + 'static>(
+ &'a self,
+ flags: irq::Flags,
+ irq_name: &CStr,
+ name: &'static CStr,
+ handler: impl PinInit<T, Error> + 'a,
+ ) -> Result<impl PinInit<irq::$reg_type<T>, Error> + 'a> {
+ let request = self.$request_fn(irq_name)?;
+
+ Ok(irq::$reg_type::<T>::new(
+ request,
+ flags,
+ name,
+ handler,
+ ))
+ }
+ };
+}
+
+impl Device<Bound> {
+ /// Returns an [`IrqRequest`] for the IRQ at the given index, if any.
+ pub fn irq_by_index(&self, index: u32) -> Result<IrqRequest<'_>> {
+ // SAFETY: `self.as_raw` returns a valid pointer to a `struct platform_device`.
+ let irq = unsafe { bindings::platform_get_irq(self.as_raw(), index) };
+
+ if irq < 0 {
+ return Err(Error::from_errno(irq));
+ }
+
+ // SAFETY: `irq` is guaranteed to be a valid IRQ number for `&self`.
+ Ok(unsafe { IrqRequest::new(self.as_ref(), irq as u32) })
+ }
+
+ /// Returns an [`IrqRequest`] for the IRQ at the given index, but does not
+ /// print an error if the IRQ cannot be obtained.
+ pub fn optional_irq_by_index(&self, index: u32) -> Result<IrqRequest<'_>> {
+ // SAFETY: `self.as_raw` returns a valid pointer to a `struct platform_device`.
+ let irq = unsafe { bindings::platform_get_irq_optional(self.as_raw(), index) };
+
+ if irq < 0 {
+ return Err(Error::from_errno(irq));
+ }
+
+ // SAFETY: `irq` is guaranteed to be a valid IRQ number for `&self`.
+ Ok(unsafe { IrqRequest::new(self.as_ref(), irq as u32) })
+ }
+
+ /// Returns an [`IrqRequest`] for the IRQ with the given name, if any.
+ pub fn irq_by_name(&self, name: &CStr) -> Result<IrqRequest<'_>> {
+ // SAFETY: `self.as_raw` returns a valid pointer to a `struct platform_device`.
+ let irq = unsafe { bindings::platform_get_irq_byname(self.as_raw(), name.as_char_ptr()) };
+
+ if irq < 0 {
+ return Err(Error::from_errno(irq));
+ }
+
+ // SAFETY: `irq` is guaranteed to be a valid IRQ number for `&self`.
+ Ok(unsafe { IrqRequest::new(self.as_ref(), irq as u32) })
+ }
+
+ /// Returns an [`IrqRequest`] for the IRQ with the given name, but does not
+ /// print an error if the IRQ cannot be obtained.
+ pub fn optional_irq_by_name(&self, name: &CStr) -> Result<IrqRequest<'_>> {
+ // SAFETY: `self.as_raw` returns a valid pointer to a `struct platform_device`.
+ let irq = unsafe {
+ bindings::platform_get_irq_byname_optional(self.as_raw(), name.as_char_ptr())
+ };
+
+ if irq < 0 {
+ return Err(Error::from_errno(irq));
+ }
+
+ // SAFETY: `irq` is guaranteed to be a valid IRQ number for `&self`.
+ Ok(unsafe { IrqRequest::new(self.as_ref(), irq as u32) })
+ }
+
+ define_irq_accessor_by_index!(
+ /// Returns a [`irq::Registration`] for the IRQ at the given index.
+ request_irq_by_index,
+ irq_by_index,
+ Registration,
+ Handler
+ );
+ define_irq_accessor_by_name!(
+ /// Returns a [`irq::Registration`] for the IRQ with the given name.
+ request_irq_by_name,
+ irq_by_name,
+ Registration,
+ Handler
+ );
+ define_irq_accessor_by_index!(
+ /// Does the same as [`Self::request_irq_by_index`], except that it does
+ /// not print an error message if the IRQ cannot be obtained.
+ request_optional_irq_by_index,
+ optional_irq_by_index,
+ Registration,
+ Handler
+ );
+ define_irq_accessor_by_name!(
+ /// Does the same as [`Self::request_irq_by_name`], except that it does
+ /// not print an error message if the IRQ cannot be obtained.
+ request_optional_irq_by_name,
+ optional_irq_by_name,
+ Registration,
+ Handler
+ );
+
+ define_irq_accessor_by_index!(
+ /// Returns a [`irq::ThreadedRegistration`] for the IRQ at the given index.
+ request_threaded_irq_by_index,
+ irq_by_index,
+ ThreadedRegistration,
+ ThreadedHandler
+ );
+ define_irq_accessor_by_name!(
+ /// Returns a [`irq::ThreadedRegistration`] for the IRQ with the given name.
+ request_threaded_irq_by_name,
+ irq_by_name,
+ ThreadedRegistration,
+ ThreadedHandler
+ );
+ define_irq_accessor_by_index!(
+ /// Does the same as [`Self::request_threaded_irq_by_index`], except
+ /// that it does not print an error message if the IRQ cannot be
+ /// obtained.
+ request_optional_threaded_irq_by_index,
+ optional_irq_by_index,
+ ThreadedRegistration,
+ ThreadedHandler
+ );
+ define_irq_accessor_by_name!(
+ /// Does the same as [`Self::request_threaded_irq_by_name`], except that
+ /// it does not print an error message if the IRQ cannot be obtained.
+ request_optional_threaded_irq_by_name,
+ optional_irq_by_name,
+ ThreadedRegistration,
+ ThreadedHandler
+ );
+}
+
+// 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 crate::dma::Device for Device<device::Core> {}
+
+// 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::get_device(self.as_ref().as_raw()) };
+ }
+
+ unsafe fn dec_ref(obj: NonNull<Self>) {
+ // SAFETY: The safety requirements guarantee that the refcount is non-zero.
+ unsafe { bindings::platform_device_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 platform_device`.
+ let dev = unsafe { addr_of_mut!((*self.as_raw()).dev) };
+
+ // SAFETY: `dev` points to a valid `struct device`.
+ 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_platform(dev.as_raw()) } {
+ return Err(EINVAL);
+ }
+
+ // SAFETY: We've just verified that the bus type of `dev` equals
+ // `bindings::platform_bus_type`, hence `dev` must be embedded in a valid
+ // `struct platform_device` as guaranteed by the corresponding C code.
+ let pdev = unsafe { container_of!(dev.as_raw(), bindings::platform_device, dev) };
+
+ // SAFETY: `pdev` is a valid pointer to a `struct platform_device`.
+ Ok(unsafe { &*pdev.cast() })
+ }
+}
+
+// SAFETY: A `Device` is always reference-counted and can be released from any thread.
+unsafe impl Send for Device {}
+
+// SAFETY: `Device` can be shared among threads because all methods of `Device`
+// (i.e. `Device<Normal>) are thread safe.
+unsafe impl Sync for Device {}
generated by cgit v1.2.3 (git 2.0.4) at 2025-12-25 12:23:41 +0000