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authorDmitry Torokhov <dmitry.torokhov@gmail.com>2024-07-15 14:03:44 -0700
committerDmitry Torokhov <dmitry.torokhov@gmail.com>2024-07-15 14:03:44 -0700
commita23e1966932464e1c5226cb9ac4ce1d5fc10ba22 (patch)
treebf5f1b57faa01ca31656bfc48c7d6b6f0bc39189 /rust/kernel
parentInput: ads7846 - use spi_device_id table (diff)
parentInput: yealink - simplify locking in sysfs attribute handling (diff)
downloadwireguard-linux-a23e1966932464e1c5226cb9ac4ce1d5fc10ba22.tar.xz
wireguard-linux-a23e1966932464e1c5226cb9ac4ce1d5fc10ba22.zip
Merge branch 'next' into for-linus
Prepare input updates for 6.11 merge window.
Diffstat (limited to 'rust/kernel')
-rw-r--r--rust/kernel/allocator.rs88
-rw-r--r--rust/kernel/error.rs20
-rw-r--r--rust/kernel/init.rs715
-rw-r--r--rust/kernel/init/__internal.rs39
-rw-r--r--rust/kernel/init/macros.rs519
-rw-r--r--rust/kernel/ioctl.rs8
-rw-r--r--rust/kernel/kunit.rs163
-rw-r--r--rust/kernel/lib.rs46
-rw-r--r--rust/kernel/net.rs6
-rw-r--r--rust/kernel/net/phy.rs905
-rw-r--r--rust/kernel/prelude.rs2
-rw-r--r--rust/kernel/print.rs9
-rw-r--r--rust/kernel/str.rs203
-rw-r--r--rust/kernel/sync.rs5
-rw-r--r--rust/kernel/sync/arc.rs67
-rw-r--r--rust/kernel/sync/condvar.rs133
-rw-r--r--rust/kernel/sync/lock.rs26
-rw-r--r--rust/kernel/sync/lock/mutex.rs6
-rw-r--r--rust/kernel/sync/lock/spinlock.rs8
-rw-r--r--rust/kernel/sync/locked_by.rs7
-rw-r--r--rust/kernel/task.rs28
-rw-r--r--rust/kernel/time.rs20
-rw-r--r--rust/kernel/types.rs49
-rw-r--r--rust/kernel/workqueue.rs681
24 files changed, 3105 insertions, 648 deletions
diff --git a/rust/kernel/allocator.rs b/rust/kernel/allocator.rs
index 9363b527be66..01ad139e19bc 100644
--- a/rust/kernel/allocator.rs
+++ b/rust/kernel/allocator.rs
@@ -21,7 +21,7 @@ unsafe fn krealloc_aligned(ptr: *mut u8, new_layout: Layout, flags: bindings::gf
let mut size = layout.size();
- if layout.align() > bindings::BINDINGS_ARCH_SLAB_MINALIGN {
+ if layout.align() > bindings::ARCH_SLAB_MINALIGN {
// The alignment requirement exceeds the slab guarantee, thus try to enlarge the size
// to use the "power-of-two" size/alignment guarantee (see comments in `kmalloc()` for
// more information).
@@ -35,15 +35,15 @@ unsafe fn krealloc_aligned(ptr: *mut u8, new_layout: Layout, flags: bindings::gf
// - `ptr` is either null or a pointer returned from a previous `k{re}alloc()` by the
// function safety requirement.
// - `size` is greater than 0 since it's either a `layout.size()` (which cannot be zero
- // according to the function safety requirement) or a result from `next_power_of_two()`.
+ // according to the function safety requirement) or a result from `next_power_of_two()`.
unsafe { bindings::krealloc(ptr as *const core::ffi::c_void, size, flags) as *mut u8 }
}
unsafe impl GlobalAlloc for KernelAllocator {
unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
- // `krealloc()` is used instead of `kmalloc()` because the latter is
- // an inline function and cannot be bound to as a result.
- unsafe { bindings::krealloc(ptr::null(), layout.size(), bindings::GFP_KERNEL) as *mut u8 }
+ // SAFETY: `ptr::null_mut()` is null and `layout` has a non-zero size by the function safety
+ // requirement.
+ unsafe { krealloc_aligned(ptr::null_mut(), layout, bindings::GFP_KERNEL) }
}
unsafe fn dealloc(&self, ptr: *mut u8, _layout: Layout) {
@@ -51,58 +51,38 @@ unsafe impl GlobalAlloc for KernelAllocator {
bindings::kfree(ptr as *const core::ffi::c_void);
}
}
-}
-
-#[global_allocator]
-static ALLOCATOR: KernelAllocator = KernelAllocator;
-
-// `rustc` only generates these for some crate types. Even then, we would need
-// to extract the object file that has them from the archive. For the moment,
-// let's generate them ourselves instead.
-//
-// Note: Although these are *safe* functions, they are called by the compiler
-// with parameters that obey the same `GlobalAlloc` function safety
-// requirements: size and align should form a valid layout, and size is
-// greater than 0.
-//
-// Note that `#[no_mangle]` implies exported too, nowadays.
-#[no_mangle]
-fn __rust_alloc(size: usize, align: usize) -> *mut u8 {
- // SAFETY: See assumption above.
- let layout = unsafe { Layout::from_size_align_unchecked(size, align) };
- // SAFETY: `ptr::null_mut()` is null, per assumption above the size of `layout` is greater
- // than 0.
- unsafe { krealloc_aligned(ptr::null_mut(), layout, bindings::GFP_KERNEL) }
-}
+ unsafe fn realloc(&self, ptr: *mut u8, layout: Layout, new_size: usize) -> *mut u8 {
+ // SAFETY:
+ // - `new_size`, when rounded up to the nearest multiple of `layout.align()`, will not
+ // overflow `isize` by the function safety requirement.
+ // - `layout.align()` is a proper alignment (i.e. not zero and must be a power of two).
+ let layout = unsafe { Layout::from_size_align_unchecked(new_size, layout.align()) };
+
+ // SAFETY:
+ // - `ptr` is either null or a pointer allocated by this allocator by the function safety
+ // requirement.
+ // - the size of `layout` is not zero because `new_size` is not zero by the function safety
+ // requirement.
+ unsafe { krealloc_aligned(ptr, layout, bindings::GFP_KERNEL) }
+ }
-#[no_mangle]
-fn __rust_dealloc(ptr: *mut u8, _size: usize, _align: usize) {
- unsafe { bindings::kfree(ptr as *const core::ffi::c_void) };
+ unsafe fn alloc_zeroed(&self, layout: Layout) -> *mut u8 {
+ // SAFETY: `ptr::null_mut()` is null and `layout` has a non-zero size by the function safety
+ // requirement.
+ unsafe {
+ krealloc_aligned(
+ ptr::null_mut(),
+ layout,
+ bindings::GFP_KERNEL | bindings::__GFP_ZERO,
+ )
+ }
+ }
}
-#[no_mangle]
-fn __rust_realloc(ptr: *mut u8, _old_size: usize, align: usize, new_size: usize) -> *mut u8 {
- // SAFETY: See assumption above.
- let new_layout = unsafe { Layout::from_size_align_unchecked(new_size, align) };
-
- // SAFETY: Per assumption above, `ptr` is allocated by `__rust_*` before, and the size of
- // `new_layout` is greater than 0.
- unsafe { krealloc_aligned(ptr, new_layout, bindings::GFP_KERNEL) }
-}
+#[global_allocator]
+static ALLOCATOR: KernelAllocator = KernelAllocator;
+// See <https://github.com/rust-lang/rust/pull/86844>.
#[no_mangle]
-fn __rust_alloc_zeroed(size: usize, align: usize) -> *mut u8 {
- // SAFETY: See assumption above.
- let layout = unsafe { Layout::from_size_align_unchecked(size, align) };
-
- // SAFETY: `ptr::null_mut()` is null, per assumption above the size of `layout` is greater
- // than 0.
- unsafe {
- krealloc_aligned(
- ptr::null_mut(),
- layout,
- bindings::GFP_KERNEL | bindings::__GFP_ZERO,
- )
- }
-}
+static __rust_no_alloc_shim_is_unstable: u8 = 0;
diff --git a/rust/kernel/error.rs b/rust/kernel/error.rs
index 05fcab6abfe6..4786d3ee1e92 100644
--- a/rust/kernel/error.rs
+++ b/rust/kernel/error.rs
@@ -2,7 +2,7 @@
//! Kernel errors.
//!
-//! C header: [`include/uapi/asm-generic/errno-base.h`](../../../include/uapi/asm-generic/errno-base.h)
+//! C header: [`include/uapi/asm-generic/errno-base.h`](srctree/include/uapi/asm-generic/errno-base.h)
use crate::str::CStr;
@@ -37,7 +37,7 @@ pub mod code {
declare_err!(E2BIG, "Argument list too long.");
declare_err!(ENOEXEC, "Exec format error.");
declare_err!(EBADF, "Bad file number.");
- declare_err!(ECHILD, "Exec format error.");
+ declare_err!(ECHILD, "No child processes.");
declare_err!(EAGAIN, "Try again.");
declare_err!(ENOMEM, "Out of memory.");
declare_err!(EACCES, "Permission denied.");
@@ -133,7 +133,7 @@ impl Error {
/// Returns the error encoded as a pointer.
#[allow(dead_code)]
pub(crate) fn to_ptr<T>(self) -> *mut T {
- // SAFETY: self.0 is a valid error due to its invariant.
+ // SAFETY: `self.0` is a valid error due to its invariant.
unsafe { bindings::ERR_PTR(self.0.into()) as *mut _ }
}
@@ -264,13 +264,9 @@ pub fn to_result(err: core::ffi::c_int) -> Result {
/// pdev: &mut PlatformDevice,
/// index: u32,
/// ) -> Result<*mut core::ffi::c_void> {
-/// // SAFETY: FFI call.
-/// unsafe {
-/// from_err_ptr(bindings::devm_platform_ioremap_resource(
-/// pdev.to_ptr(),
-/// index,
-/// ))
-/// }
+/// // SAFETY: `pdev` points to a valid platform device. There are no safety requirements
+/// // on `index`.
+/// from_err_ptr(unsafe { bindings::devm_platform_ioremap_resource(pdev.to_ptr(), index) })
/// }
/// ```
// TODO: Remove `dead_code` marker once an in-kernel client is available.
@@ -335,3 +331,7 @@ where
Err(e) => T::from(e.to_errno() as i16),
}
}
+
+/// Error message for calling a default function of a [`#[vtable]`](macros::vtable) trait.
+pub const VTABLE_DEFAULT_ERROR: &str =
+ "This function must not be called, see the #[vtable] documentation.";
diff --git a/rust/kernel/init.rs b/rust/kernel/init.rs
index b4332a4ec1f4..09004b56fb65 100644
--- a/rust/kernel/init.rs
+++ b/rust/kernel/init.rs
@@ -35,8 +35,8 @@
//! that you need to write `<-` instead of `:` for fields that you want to initialize in-place.
//!
//! ```rust
-//! # #![allow(clippy::disallowed_names, clippy::new_ret_no_self)]
-//! use kernel::{prelude::*, sync::Mutex, new_mutex};
+//! # #![allow(clippy::disallowed_names)]
+//! use kernel::sync::{new_mutex, Mutex};
//! # use core::pin::Pin;
//! #[pin_data]
//! struct Foo {
@@ -55,8 +55,8 @@
//! (or just the stack) to actually initialize a `Foo`:
//!
//! ```rust
-//! # #![allow(clippy::disallowed_names, clippy::new_ret_no_self)]
-//! # use kernel::{prelude::*, sync::Mutex, new_mutex};
+//! # #![allow(clippy::disallowed_names)]
+//! # use kernel::sync::{new_mutex, Mutex};
//! # use core::pin::Pin;
//! # #[pin_data]
//! # struct Foo {
@@ -79,14 +79,14 @@
//! above method only works for types where you can access the fields.
//!
//! ```rust
-//! # use kernel::{new_mutex, sync::{Arc, Mutex}};
+//! # use kernel::sync::{new_mutex, Arc, Mutex};
//! let mtx: Result<Arc<Mutex<usize>>> = Arc::pin_init(new_mutex!(42, "example::mtx"));
//! ```
//!
//! To declare an init macro/function you just return an [`impl PinInit<T, E>`]:
//!
//! ```rust
-//! # #![allow(clippy::disallowed_names, clippy::new_ret_no_self)]
+//! # #![allow(clippy::disallowed_names)]
//! # use kernel::{sync::Mutex, prelude::*, new_mutex, init::PinInit, try_pin_init};
//! #[pin_data]
//! struct DriverData {
@@ -120,14 +120,24 @@
//! `slot` gets called.
//!
//! ```rust
-//! use kernel::{prelude::*, init};
+//! # #![allow(unreachable_pub, clippy::disallowed_names)]
+//! use kernel::{prelude::*, init, types::Opaque};
//! use core::{ptr::addr_of_mut, marker::PhantomPinned, pin::Pin};
//! # mod bindings {
+//! # #![allow(non_camel_case_types)]
//! # pub struct foo;
//! # pub unsafe fn init_foo(_ptr: *mut foo) {}
//! # pub unsafe fn destroy_foo(_ptr: *mut foo) {}
//! # pub unsafe fn enable_foo(_ptr: *mut foo, _flags: u32) -> i32 { 0 }
//! # }
+//! # // `Error::from_errno` is `pub(crate)` in the `kernel` crate, thus provide a workaround.
+//! # trait FromErrno {
+//! # fn from_errno(errno: core::ffi::c_int) -> Error {
+//! # // Dummy error that can be constructed outside the `kernel` crate.
+//! # Error::from(core::fmt::Error)
+//! # }
+//! # }
+//! # impl FromErrno for Error {}
//! /// # Invariants
//! ///
//! /// `foo` is always initialized
@@ -158,7 +168,7 @@
//! if err != 0 {
//! // Enabling has failed, first clean up the foo and then return the error.
//! bindings::destroy_foo(Opaque::raw_get(foo));
-//! return Err(Error::from_kernel_errno(err));
+//! return Err(Error::from_errno(err));
//! }
//!
//! // All fields of `RawFoo` have been initialized, since `_p` is a ZST.
@@ -202,11 +212,12 @@
use crate::{
error::{self, Error},
sync::UniqueArc,
+ types::{Opaque, ScopeGuard},
};
use alloc::boxed::Box;
use core::{
alloc::AllocError,
- cell::Cell,
+ cell::UnsafeCell,
convert::Infallible,
marker::PhantomData,
mem::MaybeUninit,
@@ -225,9 +236,8 @@ pub mod macros;
/// # Examples
///
/// ```rust
-/// # #![allow(clippy::disallowed_names, clippy::new_ret_no_self)]
-/// # use kernel::{init, pin_init, stack_pin_init, init::*, sync::Mutex, new_mutex};
-/// # use macros::pin_data;
+/// # #![allow(clippy::disallowed_names)]
+/// # use kernel::{init, macros::pin_data, pin_init, stack_pin_init, init::*, sync::Mutex, new_mutex};
/// # use core::pin::Pin;
/// #[pin_data]
/// struct Foo {
@@ -277,8 +287,8 @@ macro_rules! stack_pin_init {
///
/// # Examples
///
-/// ```rust
-/// # #![allow(clippy::disallowed_names, clippy::new_ret_no_self)]
+/// ```rust,ignore
+/// # #![allow(clippy::disallowed_names)]
/// # use kernel::{init, pin_init, stack_try_pin_init, init::*, sync::Mutex, new_mutex};
/// # use macros::pin_data;
/// # use core::{alloc::AllocError, pin::Pin};
@@ -303,8 +313,8 @@ macro_rules! stack_pin_init {
/// pr_info!("a: {}", &*foo.a.lock());
/// ```
///
-/// ```rust
-/// # #![allow(clippy::disallowed_names, clippy::new_ret_no_self)]
+/// ```rust,ignore
+/// # #![allow(clippy::disallowed_names)]
/// # use kernel::{init, pin_init, stack_try_pin_init, init::*, sync::Mutex, new_mutex};
/// # use macros::pin_data;
/// # use core::{alloc::AllocError, pin::Pin};
@@ -356,7 +366,7 @@ macro_rules! stack_try_pin_init {
/// The syntax is almost identical to that of a normal `struct` initializer:
///
/// ```rust
-/// # #![allow(clippy::disallowed_names, clippy::new_ret_no_self)]
+/// # #![allow(clippy::disallowed_names)]
/// # use kernel::{init, pin_init, macros::pin_data, init::*};
/// # use core::pin::Pin;
/// #[pin_data]
@@ -401,7 +411,7 @@ macro_rules! stack_try_pin_init {
/// To create an initializer function, simply declare it like this:
///
/// ```rust
-/// # #![allow(clippy::disallowed_names, clippy::new_ret_no_self)]
+/// # #![allow(clippy::disallowed_names)]
/// # use kernel::{init, pin_init, prelude::*, init::*};
/// # use core::pin::Pin;
/// # #[pin_data]
@@ -428,7 +438,7 @@ macro_rules! stack_try_pin_init {
/// Users of `Foo` can now create it like this:
///
/// ```rust
-/// # #![allow(clippy::disallowed_names, clippy::new_ret_no_self)]
+/// # #![allow(clippy::disallowed_names)]
/// # use kernel::{init, pin_init, macros::pin_data, init::*};
/// # use core::pin::Pin;
/// # #[pin_data]
@@ -456,7 +466,7 @@ macro_rules! stack_try_pin_init {
/// They can also easily embed it into their own `struct`s:
///
/// ```rust
-/// # #![allow(clippy::disallowed_names, clippy::new_ret_no_self)]
+/// # #![allow(clippy::disallowed_names)]
/// # use kernel::{init, pin_init, macros::pin_data, init::*};
/// # use core::pin::Pin;
/// # #[pin_data]
@@ -509,14 +519,17 @@ macro_rules! stack_try_pin_init {
/// - Fields that you want to initialize in-place have to use `<-` instead of `:`.
/// - In front of the initializer you can write `&this in` to have access to a [`NonNull<Self>`]
/// pointer named `this` inside of the initializer.
+/// - Using struct update syntax one can place `..Zeroable::zeroed()` at the very end of the
+/// struct, this initializes every field with 0 and then runs all initializers specified in the
+/// body. This can only be done if [`Zeroable`] is implemented for the struct.
///
/// For instance:
///
/// ```rust
-/// # use kernel::pin_init;
-/// # use macros::pin_data;
+/// # use kernel::{macros::{Zeroable, pin_data}, pin_init};
/// # use core::{ptr::addr_of_mut, marker::PhantomPinned};
/// #[pin_data]
+/// #[derive(Zeroable)]
/// struct Buf {
/// // `ptr` points into `buf`.
/// ptr: *mut u8,
@@ -529,6 +542,10 @@ macro_rules! stack_try_pin_init {
/// ptr: unsafe { addr_of_mut!((*this.as_ptr()).buf).cast() },
/// pin: PhantomPinned,
/// });
+/// pin_init!(Buf {
+/// buf: [1; 64],
+/// ..Zeroable::zeroed()
+/// });
/// ```
///
/// [`try_pin_init!`]: kernel::try_pin_init
@@ -540,11 +557,15 @@ macro_rules! pin_init {
($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? {
$($fields:tt)*
}) => {
- $crate::try_pin_init!(
+ $crate::__init_internal!(
@this($($this)?),
@typ($t $(::<$($generics),*>)?),
@fields($($fields)*),
@error(::core::convert::Infallible),
+ @data(PinData, use_data),
+ @has_data(HasPinData, __pin_data),
+ @construct_closure(pin_init_from_closure),
+ @munch_fields($($fields)*),
)
};
}
@@ -593,205 +614,31 @@ macro_rules! try_pin_init {
($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? {
$($fields:tt)*
}) => {
- $crate::try_pin_init!(
+ $crate::__init_internal!(
@this($($this)?),
@typ($t $(::<$($generics),*>)? ),
@fields($($fields)*),
@error($crate::error::Error),
+ @data(PinData, use_data),
+ @has_data(HasPinData, __pin_data),
+ @construct_closure(pin_init_from_closure),
+ @munch_fields($($fields)*),
)
};
($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? {
$($fields:tt)*
}? $err:ty) => {
- $crate::try_pin_init!(
+ $crate::__init_internal!(
@this($($this)?),
@typ($t $(::<$($generics),*>)? ),
@fields($($fields)*),
@error($err),
+ @data(PinData, use_data),
+ @has_data(HasPinData, __pin_data),
+ @construct_closure(pin_init_from_closure),
+ @munch_fields($($fields)*),
)
};
- (
- @this($($this:ident)?),
- @typ($t:ident $(::<$($generics:ty),*>)?),
- @fields($($fields:tt)*),
- @error($err:ty),
- ) => {{
- // We do not want to allow arbitrary returns, so we declare this type as the `Ok` return
- // type and shadow it later when we insert the arbitrary user code. That way there will be
- // no possibility of returning without `unsafe`.
- struct __InitOk;
- // Get the pin data from the supplied type.
- let data = unsafe {
- use $crate::init::__internal::HasPinData;
- $t$(::<$($generics),*>)?::__pin_data()
- };
- // Ensure that `data` really is of type `PinData` and help with type inference:
- let init = $crate::init::__internal::PinData::make_closure::<_, __InitOk, $err>(
- data,
- move |slot| {
- {
- // Shadow the structure so it cannot be used to return early.
- struct __InitOk;
- // Create the `this` so it can be referenced by the user inside of the
- // expressions creating the individual fields.
- $(let $this = unsafe { ::core::ptr::NonNull::new_unchecked(slot) };)?
- // Initialize every field.
- $crate::try_pin_init!(init_slot:
- @data(data),
- @slot(slot),
- @munch_fields($($fields)*,),
- );
- // We use unreachable code to ensure that all fields have been mentioned exactly
- // once, this struct initializer will still be type-checked and complain with a
- // very natural error message if a field is forgotten/mentioned more than once.
- #[allow(unreachable_code, clippy::diverging_sub_expression)]
- if false {
- $crate::try_pin_init!(make_initializer:
- @slot(slot),
- @type_name($t),
- @munch_fields($($fields)*,),
- @acc(),
- );
- }
- // Forget all guards, since initialization was a success.
- $crate::try_pin_init!(forget_guards:
- @munch_fields($($fields)*,),
- );
- }
- Ok(__InitOk)
- }
- );
- let init = move |slot| -> ::core::result::Result<(), $err> {
- init(slot).map(|__InitOk| ())
- };
- let init = unsafe { $crate::init::pin_init_from_closure::<_, $err>(init) };
- init
- }};
- (init_slot:
- @data($data:ident),
- @slot($slot:ident),
- @munch_fields($(,)?),
- ) => {
- // Endpoint of munching, no fields are left.
- };
- (init_slot:
- @data($data:ident),
- @slot($slot:ident),
- // In-place initialization syntax.
- @munch_fields($field:ident <- $val:expr, $($rest:tt)*),
- ) => {
- let $field = $val;
- // Call the initializer.
- //
- // SAFETY: `slot` is valid, because we are inside of an initializer closure, we
- // return when an error/panic occurs.
- // We also use the `data` to require the correct trait (`Init` or `PinInit`) for `$field`.
- unsafe { $data.$field(::core::ptr::addr_of_mut!((*$slot).$field), $field)? };
- // Create the drop guard.
- //
- // We only give access to `&DropGuard`, so it cannot be forgotten via safe code.
- //
- // SAFETY: We forget the guard later when initialization has succeeded.
- let $field = &unsafe {
- $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
- };
-
- $crate::try_pin_init!(init_slot:
- @data($data),
- @slot($slot),
- @munch_fields($($rest)*),
- );
- };
- (init_slot:
- @data($data:ident),
- @slot($slot:ident),
- // Direct value init, this is safe for every field.
- @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*),
- ) => {
- $(let $field = $val;)?
- // Initialize the field.
- //
- // SAFETY: The memory at `slot` is uninitialized.
- unsafe { ::core::ptr::write(::core::ptr::addr_of_mut!((*$slot).$field), $field) };
- // Create the drop guard:
- //
- // We only give access to `&DropGuard`, so it cannot be accidentally forgotten.
- //
- // SAFETY: We forget the guard later when initialization has succeeded.
- let $field = &unsafe {
- $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
- };
-
- $crate::try_pin_init!(init_slot:
- @data($data),
- @slot($slot),
- @munch_fields($($rest)*),
- );
- };
- (make_initializer:
- @slot($slot:ident),
- @type_name($t:ident),
- @munch_fields($(,)?),
- @acc($($acc:tt)*),
- ) => {
- // Endpoint, nothing more to munch, create the initializer.
- // Since we are in the `if false` branch, this will never get executed. We abuse `slot` to
- // get the correct type inference here:
- unsafe {
- ::core::ptr::write($slot, $t {
- $($acc)*
- });
- }
- };
- (make_initializer:
- @slot($slot:ident),
- @type_name($t:ident),
- @munch_fields($field:ident <- $val:expr, $($rest:tt)*),
- @acc($($acc:tt)*),
- ) => {
- $crate::try_pin_init!(make_initializer:
- @slot($slot),
- @type_name($t),
- @munch_fields($($rest)*),
- @acc($($acc)* $field: ::core::panic!(),),
- );
- };
- (make_initializer:
- @slot($slot:ident),
- @type_name($t:ident),
- @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*),
- @acc($($acc:tt)*),
- ) => {
- $crate::try_pin_init!(make_initializer:
- @slot($slot),
- @type_name($t),
- @munch_fields($($rest)*),
- @acc($($acc)* $field: ::core::panic!(),),
- );
- };
- (forget_guards:
- @munch_fields($(,)?),
- ) => {
- // Munching finished.
- };
- (forget_guards:
- @munch_fields($field:ident <- $val:expr, $($rest:tt)*),
- ) => {
- unsafe { $crate::init::__internal::DropGuard::forget($field) };
-
- $crate::try_pin_init!(forget_guards:
- @munch_fields($($rest)*),
- );
- };
- (forget_guards:
- @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*),
- ) => {
- unsafe { $crate::init::__internal::DropGuard::forget($field) };
-
- $crate::try_pin_init!(forget_guards:
- @munch_fields($($rest)*),
- );
- };
}
/// Construct an in-place initializer for `struct`s.
@@ -816,11 +663,15 @@ macro_rules! init {
($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? {
$($fields:tt)*
}) => {
- $crate::try_init!(
+ $crate::__init_internal!(
@this($($this)?),
@typ($t $(::<$($generics),*>)?),
@fields($($fields)*),
@error(::core::convert::Infallible),
+ @data(InitData, /*no use_data*/),
+ @has_data(HasInitData, __init_data),
+ @construct_closure(init_from_closure),
+ @munch_fields($($fields)*),
)
}
}
@@ -841,7 +692,7 @@ macro_rules! init {
/// # Examples
///
/// ```rust
-/// use kernel::{init::PinInit, error::Error, InPlaceInit};
+/// use kernel::{init::{PinInit, zeroed}, error::Error};
/// struct BigBuf {
/// big: Box<[u8; 1024 * 1024 * 1024]>,
/// small: [u8; 1024 * 1024],
@@ -863,199 +714,31 @@ macro_rules! try_init {
($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? {
$($fields:tt)*
}) => {
- $crate::try_init!(
+ $crate::__init_internal!(
@this($($this)?),
@typ($t $(::<$($generics),*>)?),
@fields($($fields)*),
@error($crate::error::Error),
+ @data(InitData, /*no use_data*/),
+ @has_data(HasInitData, __init_data),
+ @construct_closure(init_from_closure),
+ @munch_fields($($fields)*),
)
};
($(&$this:ident in)? $t:ident $(::<$($generics:ty),* $(,)?>)? {
$($fields:tt)*
}? $err:ty) => {
- $crate::try_init!(
+ $crate::__init_internal!(
@this($($this)?),
@typ($t $(::<$($generics),*>)?),
@fields($($fields)*),
@error($err),
+ @data(InitData, /*no use_data*/),
+ @has_data(HasInitData, __init_data),
+ @construct_closure(init_from_closure),
+ @munch_fields($($fields)*),
)
};
- (
- @this($($this:ident)?),
- @typ($t:ident $(::<$($generics:ty),*>)?),
- @fields($($fields:tt)*),
- @error($err:ty),
- ) => {{
- // We do not want to allow arbitrary returns, so we declare this type as the `Ok` return
- // type and shadow it later when we insert the arbitrary user code. That way there will be
- // no possibility of returning without `unsafe`.
- struct __InitOk;
- // Get the init data from the supplied type.
- let data = unsafe {
- use $crate::init::__internal::HasInitData;
- $t$(::<$($generics),*>)?::__init_data()
- };
- // Ensure that `data` really is of type `InitData` and help with type inference:
- let init = $crate::init::__internal::InitData::make_closure::<_, __InitOk, $err>(
- data,
- move |slot| {
- {
- // Shadow the structure so it cannot be used to return early.
- struct __InitOk;
- // Create the `this` so it can be referenced by the user inside of the
- // expressions creating the individual fields.
- $(let $this = unsafe { ::core::ptr::NonNull::new_unchecked(slot) };)?
- // Initialize every field.
- $crate::try_init!(init_slot:
- @slot(slot),
- @munch_fields($($fields)*,),
- );
- // We use unreachable code to ensure that all fields have been mentioned exactly
- // once, this struct initializer will still be type-checked and complain with a
- // very natural error message if a field is forgotten/mentioned more than once.
- #[allow(unreachable_code, clippy::diverging_sub_expression)]
- if false {
- $crate::try_init!(make_initializer:
- @slot(slot),
- @type_name($t),
- @munch_fields($($fields)*,),
- @acc(),
- );
- }
- // Forget all guards, since initialization was a success.
- $crate::try_init!(forget_guards:
- @munch_fields($($fields)*,),
- );
- }
- Ok(__InitOk)
- }
- );
- let init = move |slot| -> ::core::result::Result<(), $err> {
- init(slot).map(|__InitOk| ())
- };
- let init = unsafe { $crate::init::init_from_closure::<_, $err>(init) };
- init
- }};
- (init_slot:
- @slot($slot:ident),
- @munch_fields( $(,)?),
- ) => {
- // Endpoint of munching, no fields are left.
- };
- (init_slot:
- @slot($slot:ident),
- @munch_fields($field:ident <- $val:expr, $($rest:tt)*),
- ) => {
- let $field = $val;
- // Call the initializer.
- //
- // SAFETY: `slot` is valid, because we are inside of an initializer closure, we
- // return when an error/panic occurs.
- unsafe {
- $crate::init::Init::__init($field, ::core::ptr::addr_of_mut!((*$slot).$field))?;
- }
- // Create the drop guard.
- //
- // We only give access to `&DropGuard`, so it cannot be accidentally forgotten.
- //
- // SAFETY: We forget the guard later when initialization has succeeded.
- let $field = &unsafe {
- $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
- };
-
- $crate::try_init!(init_slot:
- @slot($slot),
- @munch_fields($($rest)*),
- );
- };
- (init_slot:
- @slot($slot:ident),
- // Direct value init.
- @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*),
- ) => {
- $(let $field = $val;)?
- // Call the initializer.
- //
- // SAFETY: The memory at `slot` is uninitialized.
- unsafe { ::core::ptr::write(::core::ptr::addr_of_mut!((*$slot).$field), $field) };
- // Create the drop guard.
- //
- // We only give access to `&DropGuard`, so it cannot be accidentally forgotten.
- //
- // SAFETY: We forget the guard later when initialization has succeeded.
- let $field = &unsafe {
- $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
- };
-
- $crate::try_init!(init_slot:
- @slot($slot),
- @munch_fields($($rest)*),
- );
- };
- (make_initializer:
- @slot($slot:ident),
- @type_name($t:ident),
- @munch_fields( $(,)?),
- @acc($($acc:tt)*),
- ) => {
- // Endpoint, nothing more to munch, create the initializer.
- // Since we are in the `if false` branch, this will never get executed. We abuse `slot` to
- // get the correct type inference here:
- unsafe {
- ::core::ptr::write($slot, $t {
- $($acc)*
- });
- }
- };
- (make_initializer:
- @slot($slot:ident),
- @type_name($t:ident),
- @munch_fields($field:ident <- $val:expr, $($rest:tt)*),
- @acc($($acc:tt)*),
- ) => {
- $crate::try_init!(make_initializer:
- @slot($slot),
- @type_name($t),
- @munch_fields($($rest)*),
- @acc($($acc)*$field: ::core::panic!(),),
- );
- };
- (make_initializer:
- @slot($slot:ident),
- @type_name($t:ident),
- @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*),
- @acc($($acc:tt)*),
- ) => {
- $crate::try_init!(make_initializer:
- @slot($slot),
- @type_name($t),
- @munch_fields($($rest)*),
- @acc($($acc)*$field: ::core::panic!(),),
- );
- };
- (forget_guards:
- @munch_fields($(,)?),
- ) => {
- // Munching finished.
- };
- (forget_guards:
- @munch_fields($field:ident <- $val:expr, $($rest:tt)*),
- ) => {
- unsafe { $crate::init::__internal::DropGuard::forget($field) };
-
- $crate::try_init!(forget_guards:
- @munch_fields($($rest)*),
- );
- };
- (forget_guards:
- @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*),
- ) => {
- unsafe { $crate::init::__internal::DropGuard::forget($field) };
-
- $crate::try_init!(forget_guards:
- @munch_fields($($rest)*),
- );
- };
}
/// A pin-initializer for the type `T`.
@@ -1068,10 +751,10 @@ macro_rules! try_init {
///
/// # Safety
///
-/// When implementing this type you will need to take great care. Also there are probably very few
+/// When implementing this trait you will need to take great care. Also there are probably very few
/// cases where a manual implementation is necessary. Use [`pin_init_from_closure`] where possible.
///
-/// The [`PinInit::__pinned_init`] function
+/// The [`PinInit::__pinned_init`] function:
/// - returns `Ok(())` if it initialized every field of `slot`,
/// - returns `Err(err)` if it encountered an error and then cleaned `slot`, this means:
/// - `slot` can be deallocated without UB occurring,
@@ -1092,6 +775,79 @@ pub unsafe trait PinInit<T: ?Sized, E = Infallible>: Sized {
/// deallocate.
/// - `slot` will not move until it is dropped, i.e. it will be pinned.
unsafe fn __pinned_init(self, slot: *mut T) -> Result<(), E>;
+
+ /// First initializes the value using `self` then calls the function `f` with the initialized
+ /// value.
+ ///
+ /// If `f` returns an error the value is dropped and the initializer will forward the error.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # #![allow(clippy::disallowed_names)]
+ /// use kernel::{types::Opaque, init::pin_init_from_closure};
+ /// #[repr(C)]
+ /// struct RawFoo([u8; 16]);
+ /// extern {
+ /// fn init_foo(_: *mut RawFoo);
+ /// }
+ ///
+ /// #[pin_data]
+ /// struct Foo {
+ /// #[pin]
+ /// raw: Opaque<RawFoo>,
+ /// }
+ ///
+ /// impl Foo {
+ /// fn setup(self: Pin<&mut Self>) {
+ /// pr_info!("Setting up foo");
+ /// }
+ /// }
+ ///
+ /// let foo = pin_init!(Foo {
+ /// raw <- unsafe {
+ /// Opaque::ffi_init(|s| {
+ /// init_foo(s);
+ /// })
+ /// },
+ /// }).pin_chain(|foo| {
+ /// foo.setup();
+ /// Ok(())
+ /// });
+ /// ```
+ fn pin_chain<F>(self, f: F) -> ChainPinInit<Self, F, T, E>
+ where
+ F: FnOnce(Pin<&mut T>) -> Result<(), E>,
+ {
+ ChainPinInit(self, f, PhantomData)
+ }
+}
+
+/// An initializer returned by [`PinInit::pin_chain`].
+pub struct ChainPinInit<I, F, T: ?Sized, E>(I, F, __internal::Invariant<(E, Box<T>)>);
+
+// SAFETY: The `__pinned_init` function is implemented such that it
+// - returns `Ok(())` on successful initialization,
+// - returns `Err(err)` on error and in this case `slot` will be dropped.
+// - considers `slot` pinned.
+unsafe impl<T: ?Sized, E, I, F> PinInit<T, E> for ChainPinInit<I, F, T, E>
+where
+ I: PinInit<T, E>,
+ F: FnOnce(Pin<&mut T>) -> Result<(), E>,
+{
+ unsafe fn __pinned_init(self, slot: *mut T) -> Result<(), E> {
+ // SAFETY: All requirements fulfilled since this function is `__pinned_init`.
+ unsafe { self.0.__pinned_init(slot)? };
+ // SAFETY: The above call initialized `slot` and we still have unique access.
+ let val = unsafe { &mut *slot };
+ // SAFETY: `slot` is considered pinned.
+ let val = unsafe { Pin::new_unchecked(val) };
+ (self.1)(val).map_err(|e| {
+ // SAFETY: `slot` was initialized above.
+ unsafe { core::ptr::drop_in_place(slot) };
+ e
+ })
+ }
}
/// An initializer for `T`.
@@ -1105,10 +861,10 @@ pub unsafe trait PinInit<T: ?Sized, E = Infallible>: Sized {
///
/// # Safety
///
-/// When implementing this type you will need to take great care. Also there are probably very few
+/// When implementing this trait you will need to take great care. Also there are probably very few
/// cases where a manual implementation is necessary. Use [`init_from_closure`] where possible.
///
-/// The [`Init::__init`] function
+/// The [`Init::__init`] function:
/// - returns `Ok(())` if it initialized every field of `slot`,
/// - returns `Err(err)` if it encountered an error and then cleaned `slot`, this means:
/// - `slot` can be deallocated without UB occurring,
@@ -1124,7 +880,7 @@ pub unsafe trait PinInit<T: ?Sized, E = Infallible>: Sized {
///
/// [`Arc<T>`]: crate::sync::Arc
#[must_use = "An initializer must be used in order to create its value."]
-pub unsafe trait Init<T: ?Sized, E = Infallible>: Sized {
+pub unsafe trait Init<T: ?Sized, E = Infallible>: PinInit<T, E> {
/// Initializes `slot`.
///
/// # Safety
@@ -1133,16 +889,73 @@ pub unsafe trait Init<T: ?Sized, E = Infallible>: Sized {
/// - the caller does not touch `slot` when `Err` is returned, they are only permitted to
/// deallocate.
unsafe fn __init(self, slot: *mut T) -> Result<(), E>;
+
+ /// First initializes the value using `self` then calls the function `f` with the initialized
+ /// value.
+ ///
+ /// If `f` returns an error the value is dropped and the initializer will forward the error.
+ ///
+ /// # Examples
+ ///
+ /// ```rust
+ /// # #![allow(clippy::disallowed_names)]
+ /// use kernel::{types::Opaque, init::{self, init_from_closure}};
+ /// struct Foo {
+ /// buf: [u8; 1_000_000],
+ /// }
+ ///
+ /// impl Foo {
+ /// fn setup(&mut self) {
+ /// pr_info!("Setting up foo");
+ /// }
+ /// }
+ ///
+ /// let foo = init!(Foo {
+ /// buf <- init::zeroed()
+ /// }).chain(|foo| {
+ /// foo.setup();
+ /// Ok(())
+ /// });
+ /// ```
+ fn chain<F>(self, f: F) -> ChainInit<Self, F, T, E>
+ where
+ F: FnOnce(&mut T) -> Result<(), E>,
+ {
+ ChainInit(self, f, PhantomData)
+ }
+}
+
+/// An initializer returned by [`Init::chain`].
+pub struct ChainInit<I, F, T: ?Sized, E>(I, F, __internal::Invariant<(E, Box<T>)>);
+
+// SAFETY: The `__init` function is implemented such that it
+// - returns `Ok(())` on successful initialization,
+// - returns `Err(err)` on error and in this case `slot` will be dropped.
+unsafe impl<T: ?Sized, E, I, F> Init<T, E> for ChainInit<I, F, T, E>
+where
+ I: Init<T, E>,
+ F: FnOnce(&mut T) -> Result<(), E>,
+{
+ unsafe fn __init(self, slot: *mut T) -> Result<(), E> {
+ // SAFETY: All requirements fulfilled since this function is `__init`.
+ unsafe { self.0.__pinned_init(slot)? };
+ // SAFETY: The above call initialized `slot` and we still have unique access.
+ (self.1)(unsafe { &mut *slot }).map_err(|e| {
+ // SAFETY: `slot` was initialized above.
+ unsafe { core::ptr::drop_in_place(slot) };
+ e
+ })
+ }
}
-// SAFETY: Every in-place initializer can also be used as a pin-initializer.
-unsafe impl<T: ?Sized, E, I> PinInit<T, E> for I
+// SAFETY: `__pinned_init` behaves exactly the same as `__init`.
+unsafe impl<T: ?Sized, E, I, F> PinInit<T, E> for ChainInit<I, F, T, E>
where
I: Init<T, E>,
+ F: FnOnce(&mut T) -> Result<(), E>,
{
unsafe fn __pinned_init(self, slot: *mut T) -> Result<(), E> {
- // SAFETY: `__init` meets the same requirements as `__pinned_init`, except that it does not
- // require `slot` to not move after init.
+ // SAFETY: `__init` has less strict requirements compared to `__pinned_init`.
unsafe { self.__init(slot) }
}
}
@@ -1194,6 +1007,93 @@ pub fn uninit<T, E>() -> impl Init<MaybeUninit<T>, E> {
unsafe { init_from_closure(|_| Ok(())) }
}
+/// Initializes an array by initializing each element via the provided initializer.
+///
+/// # Examples
+///
+/// ```rust
+/// use kernel::{error::Error, init::init_array_from_fn};
+/// let array: Box<[usize; 1_000]> = Box::init::<Error>(init_array_from_fn(|i| i)).unwrap();
+/// assert_eq!(array.len(), 1_000);
+/// ```
+pub fn init_array_from_fn<I, const N: usize, T, E>(
+ mut make_init: impl FnMut(usize) -> I,
+) -> impl Init<[T; N], E>
+where
+ I: Init<T, E>,
+{
+ let init = move |slot: *mut [T; N]| {
+ let slot = slot.cast::<T>();
+ // Counts the number of initialized elements and when dropped drops that many elements from
+ // `slot`.
+ let mut init_count = ScopeGuard::new_with_data(0, |i| {
+ // We now free every element that has been initialized before.
+ // SAFETY: The loop initialized exactly the values from 0..i and since we
+ // return `Err` below, the caller will consider the memory at `slot` as
+ // uninitialized.
+ unsafe { ptr::drop_in_place(ptr::slice_from_raw_parts_mut(slot, i)) };
+ });
+ for i in 0..N {
+ let init = make_init(i);
+ // SAFETY: Since 0 <= `i` < N, it is still in bounds of `[T; N]`.
+ let ptr = unsafe { slot.add(i) };
+ // SAFETY: The pointer is derived from `slot` and thus satisfies the `__init`
+ // requirements.
+ unsafe { init.__init(ptr) }?;
+ *init_count += 1;
+ }
+ init_count.dismiss();
+ Ok(())
+ };
+ // SAFETY: The initializer above initializes every element of the array. On failure it drops
+ // any initialized elements and returns `Err`.
+ unsafe { init_from_closure(init) }
+}
+
+/// Initializes an array by initializing each element via the provided initializer.
+///
+/// # Examples
+///
+/// ```rust
+/// use kernel::{sync::{Arc, Mutex}, init::pin_init_array_from_fn, new_mutex};
+/// let array: Arc<[Mutex<usize>; 1_000]> =
+/// Arc::pin_init(pin_init_array_from_fn(|i| new_mutex!(i))).unwrap();
+/// assert_eq!(array.len(), 1_000);
+/// ```
+pub fn pin_init_array_from_fn<I, const N: usize, T, E>(
+ mut make_init: impl FnMut(usize) -> I,
+) -> impl PinInit<[T; N], E>
+where
+ I: PinInit<T, E>,
+{
+ let init = move |slot: *mut [T; N]| {
+ let slot = slot.cast::<T>();
+ // Counts the number of initialized elements and when dropped drops that many elements from
+ // `slot`.
+ let mut init_count = ScopeGuard::new_with_data(0, |i| {
+ // We now free every element that has been initialized before.
+ // SAFETY: The loop initialized exactly the values from 0..i and since we
+ // return `Err` below, the caller will consider the memory at `slot` as
+ // uninitialized.
+ unsafe { ptr::drop_in_place(ptr::slice_from_raw_parts_mut(slot, i)) };
+ });
+ for i in 0..N {
+ let init = make_init(i);
+ // SAFETY: Since 0 <= `i` < N, it is still in bounds of `[T; N]`.
+ let ptr = unsafe { slot.add(i) };
+ // SAFETY: The pointer is derived from `slot` and thus satisfies the `__init`
+ // requirements.
+ unsafe { init.__pinned_init(ptr) }?;
+ *init_count += 1;
+ }
+ init_count.dismiss();
+ Ok(())
+ };
+ // SAFETY: The initializer above initializes every element of the array. On failure it drops
+ // any initialized elements and returns `Err`.
+ unsafe { pin_init_from_closure(init) }
+}
+
// SAFETY: Every type can be initialized by-value.
unsafe impl<T, E> Init<T, E> for T {
unsafe fn __init(self, slot: *mut T) -> Result<(), E> {
@@ -1202,6 +1102,13 @@ unsafe impl<T, E> Init<T, E> for T {
}
}
+// SAFETY: Every type can be initialized by-value. `__pinned_init` calls `__init`.
+unsafe impl<T, E> PinInit<T, E> for T {
+ unsafe fn __pinned_init(self, slot: *mut T) -> Result<(), E> {
+ unsafe { self.__init(slot) }
+ }
+}
+
/// Smart pointer that can initialize memory in-place.
pub trait InPlaceInit<T>: Sized {
/// Use the given pin-initializer to pin-initialize a `T` inside of a new smart pointer of this
@@ -1385,11 +1292,23 @@ impl_zeroable! {
i8, i16, i32, i64, i128, isize,
f32, f64,
- // SAFETY: These are ZSTs, there is nothing to zero.
- {<T: ?Sized>} PhantomData<T>, core::marker::PhantomPinned, Infallible, (),
+ // Note: do not add uninhabited types (such as `!` or `core::convert::Infallible`) to this list;
+ // creating an instance of an uninhabited type is immediate undefined behavior. For more on
+ // uninhabited/empty types, consult The Rustonomicon:
+ // <https://doc.rust-lang.org/stable/nomicon/exotic-sizes.html#empty-types>. The Rust Reference
+ // also has information on undefined behavior:
+ // <https://doc.rust-lang.org/stable/reference/behavior-considered-undefined.html>.
+ //
+ // SAFETY: These are inhabited ZSTs; there is nothing to zero and a valid value exists.
+ {<T: ?Sized>} PhantomData<T>, core::marker::PhantomPinned, (),
// SAFETY: Type is allowed to take any value, including all zeros.
{<T>} MaybeUninit<T>,
+ // SAFETY: Type is allowed to take any value, including all zeros.
+ {<T>} Opaque<T>,
+
+ // SAFETY: `T: Zeroable` and `UnsafeCell` is `repr(transparent)`.
+ {<T: ?Sized + Zeroable>} UnsafeCell<T>,
// SAFETY: All zeros is equivalent to `None` (option layout optimization guarantee).
Option<NonZeroU8>, Option<NonZeroU16>, Option<NonZeroU32>, Option<NonZeroU64>,
diff --git a/rust/kernel/init/__internal.rs b/rust/kernel/init/__internal.rs
index 44751fb62b51..db3372619ecd 100644
--- a/rust/kernel/init/__internal.rs
+++ b/rust/kernel/init/__internal.rs
@@ -13,7 +13,7 @@ use super::*;
///
/// [nomicon]: https://doc.rust-lang.org/nomicon/subtyping.html
/// [this table]: https://doc.rust-lang.org/nomicon/phantom-data.html#table-of-phantomdata-patterns
-type Invariant<T> = PhantomData<fn(*mut T) -> *mut T>;
+pub(super) type Invariant<T> = PhantomData<fn(*mut T) -> *mut T>;
/// This is the module-internal type implementing `PinInit` and `Init`. It is unsafe to create this
/// type, since the closure needs to fulfill the same safety requirement as the
@@ -32,6 +32,18 @@ where
}
}
+// SAFETY: While constructing the `InitClosure`, the user promised that it upholds the
+// `__pinned_init` invariants.
+unsafe impl<T: ?Sized, F, E> PinInit<T, E> for InitClosure<F, T, E>
+where
+ F: FnOnce(*mut T) -> Result<(), E>,
+{
+ #[inline]
+ unsafe fn __pinned_init(self, slot: *mut T) -> Result<(), E> {
+ (self.0)(slot)
+ }
+}
+
/// This trait is only implemented via the `#[pin_data]` proc-macro. It is used to facilitate
/// the pin projections within the initializers.
///
@@ -174,7 +186,6 @@ impl<T> StackInit<T> {
/// Can be forgotten to prevent the drop.
pub struct DropGuard<T: ?Sized> {
ptr: *mut T,
- do_drop: Cell<bool>,
}
impl<T: ?Sized> DropGuard<T> {
@@ -190,32 +201,16 @@ impl<T: ?Sized> DropGuard<T> {
/// - will not be dropped by any other means.
#[inline]
pub unsafe fn new(ptr: *mut T) -> Self {
- Self {
- ptr,
- do_drop: Cell::new(true),
- }
- }
-
- /// Prevents this guard from dropping the supplied pointer.
- ///
- /// # Safety
- ///
- /// This function is unsafe in order to prevent safe code from forgetting this guard. It should
- /// only be called by the macros in this module.
- #[inline]
- pub unsafe fn forget(&self) {
- self.do_drop.set(false);
+ Self { ptr }
}
}
impl<T: ?Sized> Drop for DropGuard<T> {
#[inline]
fn drop(&mut self) {
- if self.do_drop.get() {
- // SAFETY: A `DropGuard` can only be constructed using the unsafe `new` function
- // ensuring that this operation is safe.
- unsafe { ptr::drop_in_place(self.ptr) }
- }
+ // SAFETY: A `DropGuard` can only be constructed using the unsafe `new` function
+ // ensuring that this operation is safe.
+ unsafe { ptr::drop_in_place(self.ptr) }
}
}
diff --git a/rust/kernel/init/macros.rs b/rust/kernel/init/macros.rs
index 00aa4e956c0a..cb6e61b6c50b 100644
--- a/rust/kernel/init/macros.rs
+++ b/rust/kernel/init/macros.rs
@@ -1,10 +1,12 @@
// SPDX-License-Identifier: Apache-2.0 OR MIT
//! This module provides the macros that actually implement the proc-macros `pin_data` and
-//! `pinned_drop`.
+//! `pinned_drop`. It also contains `__init_internal` the implementation of the `{try_}{pin_}init!`
+//! macros.
//!
//! These macros should never be called directly, since they expect their input to be
-//! in a certain format which is internal. Use the proc-macros instead.
+//! in a certain format which is internal. If used incorrectly, these macros can lead to UB even in
+//! safe code! Use the public facing macros instead.
//!
//! This architecture has been chosen because the kernel does not yet have access to `syn` which
//! would make matters a lot easier for implementing these as proc-macros.
@@ -43,7 +45,7 @@
//! #[pinned_drop]
//! impl PinnedDrop for Foo {
//! fn drop(self: Pin<&mut Self>) {
-//! println!("{self:p} is getting dropped.");
+//! pr_info!("{self:p} is getting dropped.");
//! }
//! }
//!
@@ -168,8 +170,10 @@
//! t: T,
//! }
//! #[doc(hidden)]
-//! impl<'__pin, T>
-//! ::core::marker::Unpin for Bar<T> where __Unpin<'__pin, T>: ::core::marker::Unpin {}
+//! impl<'__pin, T> ::core::marker::Unpin for Bar<T>
+//! where
+//! __Unpin<'__pin, T>: ::core::marker::Unpin,
+//! {}
//! // Now we need to ensure that `Bar` does not implement `Drop`, since that would give users
//! // access to `&mut self` inside of `drop` even if the struct was pinned. This could lead to
//! // UB with only safe code, so we disallow this by giving a trait implementation error using
@@ -186,8 +190,9 @@
//! // for safety, but a good sanity check, since no normal code calls `PinnedDrop::drop`.
//! #[allow(non_camel_case_types)]
//! trait UselessPinnedDropImpl_you_need_to_specify_PinnedDrop {}
-//! impl<T: ::kernel::init::PinnedDrop>
-//! UselessPinnedDropImpl_you_need_to_specify_PinnedDrop for T {}
+//! impl<
+//! T: ::kernel::init::PinnedDrop,
+//! > UselessPinnedDropImpl_you_need_to_specify_PinnedDrop for T {}
//! impl<T> UselessPinnedDropImpl_you_need_to_specify_PinnedDrop for Bar<T> {}
//! };
//! ```
@@ -217,7 +222,7 @@
//! // return type and shadow it later when we insert the arbitrary user code. That way
//! // there will be no possibility of returning without `unsafe`.
//! struct __InitOk;
-//! // Get the pin-data type from the initialized type.
+//! // Get the data about fields from the supplied type.
//! // - the function is unsafe, hence the unsafe block
//! // - we `use` the `HasPinData` trait in the block, it is only available in that
//! // scope.
@@ -225,8 +230,7 @@
//! use ::kernel::init::__internal::HasPinData;
//! Self::__pin_data()
//! };
-//! // Use `data` to help with type inference, the closure supplied will have the type
-//! // `FnOnce(*mut Self) -> Result<__InitOk, Infallible>`.
+//! // Ensure that `data` really is of type `PinData` and help with type inference:
//! let init = ::kernel::init::__internal::PinData::make_closure::<
//! _,
//! __InitOk,
@@ -234,71 +238,75 @@
//! >(data, move |slot| {
//! {
//! // Shadow the structure so it cannot be used to return early. If a user
-//! // tries to write `return Ok(__InitOk)`, then they get a type error, since
-//! // that will refer to this struct instead of the one defined above.
+//! // tries to write `return Ok(__InitOk)`, then they get a type error,
+//! // since that will refer to this struct instead of the one defined
+//! // above.
//! struct __InitOk;
//! // This is the expansion of `t,`, which is syntactic sugar for `t: t,`.
-//! unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).t), t) };
-//! // Since initialization could fail later (not in this case, since the error
-//! // type is `Infallible`) we will need to drop this field if there is an
-//! // error later. This `DropGuard` will drop the field when it gets dropped
-//! // and has not yet been forgotten. We make a reference to it, so users
-//! // cannot `mem::forget` it from the initializer, since the name is the same
-//! // as the field (including hygiene).
-//! let t = &unsafe {
-//! ::kernel::init::__internal::DropGuard::new(
-//! ::core::addr_of_mut!((*slot).t),
-//! )
+//! {
+//! unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).t), t) };
+//! }
+//! // Since initialization could fail later (not in this case, since the
+//! // error type is `Infallible`) we will need to drop this field if there
+//! // is an error later. This `DropGuard` will drop the field when it gets
+//! // dropped and has not yet been forgotten.
+//! let t = unsafe {
+//! ::pinned_init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).t))
//! };
//! // Expansion of `x: 0,`:
-//! // Since this can be an arbitrary expression we cannot place it inside of
-//! // the `unsafe` block, so we bind it here.
-//! let x = 0;
-//! unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).x), x) };
+//! // Since this can be an arbitrary expression we cannot place it inside
+//! // of the `unsafe` block, so we bind it here.
+//! {
+//! let x = 0;
+//! unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).x), x) };
+//! }
//! // We again create a `DropGuard`.
-//! let x = &unsafe {
-//! ::kernel::init::__internal::DropGuard::new(
-//! ::core::addr_of_mut!((*slot).x),
-//! )
+//! let x = unsafe {
+//! ::kernel::init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).x))
//! };
-//!
+//! // Since initialization has successfully completed, we can now forget
+//! // the guards. This is not `mem::forget`, since we only have
+//! // `&DropGuard`.
+//! ::core::mem::forget(x);
+//! ::core::mem::forget(t);
//! // Here we use the type checker to ensure that every field has been
//! // initialized exactly once, since this is `if false` it will never get
//! // executed, but still type-checked.
-//! // Additionally we abuse `slot` to automatically infer the correct type for
-//! // the struct. This is also another check that every field is accessible
-//! // from this scope.
+//! // Additionally we abuse `slot` to automatically infer the correct type
+//! // for the struct. This is also another check that every field is
+//! // accessible from this scope.
//! #[allow(unreachable_code, clippy::diverging_sub_expression)]
-//! if false {
+//! let _ = || {
//! unsafe {
//! ::core::ptr::write(
//! slot,
//! Self {
-//! // We only care about typecheck finding every field here,
-//! // the expression does not matter, just conjure one using
-//! // `panic!()`:
+//! // We only care about typecheck finding every field
+//! // here, the expression does not matter, just conjure
+//! // one using `panic!()`:
//! t: ::core::panic!(),
//! x: ::core::panic!(),
//! },
//! );
//! };
-//! }
-//! // Since initialization has successfully completed, we can now forget the
-//! // guards. This is not `mem::forget`, since we only have `&DropGuard`.
-//! unsafe { ::kernel::init::__internal::DropGuard::forget(t) };
-//! unsafe { ::kernel::init::__internal::DropGuard::forget(x) };
+//! };
//! }
//! // We leave the scope above and gain access to the previously shadowed
//! // `__InitOk` that we need to return.
//! Ok(__InitOk)
//! });
//! // Change the return type from `__InitOk` to `()`.
-//! let init = move |slot| -> ::core::result::Result<(), ::core::convert::Infallible> {
+//! let init = move |
+//! slot,
+//! | -> ::core::result::Result<(), ::core::convert::Infallible> {
//! init(slot).map(|__InitOk| ())
//! };
//! // Construct the initializer.
//! let init = unsafe {
-//! ::kernel::init::pin_init_from_closure::<_, ::core::convert::Infallible>(init)
+//! ::kernel::init::pin_init_from_closure::<
+//! _,
+//! ::core::convert::Infallible,
+//! >(init)
//! };
//! init
//! }
@@ -372,7 +380,10 @@
//! b: Bar<u32>,
//! }
//! #[doc(hidden)]
-//! impl<'__pin> ::core::marker::Unpin for Foo where __Unpin<'__pin>: ::core::marker::Unpin {}
+//! impl<'__pin> ::core::marker::Unpin for Foo
+//! where
+//! __Unpin<'__pin>: ::core::marker::Unpin,
+//! {}
//! // Since we specified `PinnedDrop` as the argument to `#[pin_data]`, we expect `Foo` to
//! // implement `PinnedDrop`. Thus we do not need to prevent `Drop` implementations like
//! // before, instead we implement `Drop` here and delegate to `PinnedDrop`.
@@ -401,7 +412,7 @@
//! #[pinned_drop]
//! impl PinnedDrop for Foo {
//! fn drop(self: Pin<&mut Self>) {
-//! println!("{self:p} is getting dropped.");
+//! pr_info!("{self:p} is getting dropped.");
//! }
//! }
//! ```
@@ -412,7 +423,7 @@
//! // `unsafe`, full path and the token parameter are added, everything else stays the same.
//! unsafe impl ::kernel::init::PinnedDrop for Foo {
//! fn drop(self: Pin<&mut Self>, _: ::kernel::init::__internal::OnlyCallFromDrop) {
-//! println!("{self:p} is getting dropped.");
+//! pr_info!("{self:p} is getting dropped.");
//! }
//! }
//! ```
@@ -447,18 +458,21 @@
//! >(data, move |slot| {
//! {
//! struct __InitOk;
-//! unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).a), a) };
-//! let a = &unsafe {
+//! {
+//! unsafe { ::core::ptr::write(::core::addr_of_mut!((*slot).a), a) };
+//! }
+//! let a = unsafe {
//! ::kernel::init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).a))
//! };
-//! let b = Bar::new(36);
+//! let init = Bar::new(36);
//! unsafe { data.b(::core::addr_of_mut!((*slot).b), b)? };
-//! let b = &unsafe {
+//! let b = unsafe {
//! ::kernel::init::__internal::DropGuard::new(::core::addr_of_mut!((*slot).b))
//! };
-//!
+//! ::core::mem::forget(b);
+//! ::core::mem::forget(a);
//! #[allow(unreachable_code, clippy::diverging_sub_expression)]
-//! if false {
+//! let _ = || {
//! unsafe {
//! ::core::ptr::write(
//! slot,
@@ -468,13 +482,13 @@
//! },
//! );
//! };
-//! }
-//! unsafe { ::kernel::init::__internal::DropGuard::forget(a) };
-//! unsafe { ::kernel::init::__internal::DropGuard::forget(b) };
+//! };
//! }
//! Ok(__InitOk)
//! });
-//! let init = move |slot| -> ::core::result::Result<(), ::core::convert::Infallible> {
+//! let init = move |
+//! slot,
+//! | -> ::core::result::Result<(), ::core::convert::Infallible> {
//! init(slot).map(|__InitOk| ())
//! };
//! let init = unsafe {
@@ -960,6 +974,7 @@ macro_rules! __pin_data {
where $($whr)*
{
$(
+ $(#[$($p_attr)*])*
$pvis unsafe fn $p_field<E>(
self,
slot: *mut $p_type,
@@ -969,6 +984,7 @@ macro_rules! __pin_data {
}
)*
$(
+ $(#[$($attr)*])*
$fvis unsafe fn $field<E>(
self,
slot: *mut $type,
@@ -980,3 +996,388 @@ macro_rules! __pin_data {
}
};
}
+
+/// The internal init macro. Do not call manually!
+///
+/// This is called by the `{try_}{pin_}init!` macros with various inputs.
+///
+/// This macro has multiple internal call configurations, these are always the very first ident:
+/// - nothing: this is the base case and called by the `{try_}{pin_}init!` macros.
+/// - `with_update_parsed`: when the `..Zeroable::zeroed()` syntax has been handled.
+/// - `init_slot`: recursively creates the code that initializes all fields in `slot`.
+/// - `make_initializer`: recursively create the struct initializer that guarantees that every
+/// field has been initialized exactly once.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __init_internal {
+ (
+ @this($($this:ident)?),
+ @typ($t:path),
+ @fields($($fields:tt)*),
+ @error($err:ty),
+ // Either `PinData` or `InitData`, `$use_data` should only be present in the `PinData`
+ // case.
+ @data($data:ident, $($use_data:ident)?),
+ // `HasPinData` or `HasInitData`.
+ @has_data($has_data:ident, $get_data:ident),
+ // `pin_init_from_closure` or `init_from_closure`.
+ @construct_closure($construct_closure:ident),
+ @munch_fields(),
+ ) => {
+ $crate::__init_internal!(with_update_parsed:
+ @this($($this)?),
+ @typ($t),
+ @fields($($fields)*),
+ @error($err),
+ @data($data, $($use_data)?),
+ @has_data($has_data, $get_data),
+ @construct_closure($construct_closure),
+ @zeroed(), // Nothing means default behavior.
+ )
+ };
+ (
+ @this($($this:ident)?),
+ @typ($t:path),
+ @fields($($fields:tt)*),
+ @error($err:ty),
+ // Either `PinData` or `InitData`, `$use_data` should only be present in the `PinData`
+ // case.
+ @data($data:ident, $($use_data:ident)?),
+ // `HasPinData` or `HasInitData`.
+ @has_data($has_data:ident, $get_data:ident),
+ // `pin_init_from_closure` or `init_from_closure`.
+ @construct_closure($construct_closure:ident),
+ @munch_fields(..Zeroable::zeroed()),
+ ) => {
+ $crate::__init_internal!(with_update_parsed:
+ @this($($this)?),
+ @typ($t),
+ @fields($($fields)*),
+ @error($err),
+ @data($data, $($use_data)?),
+ @has_data($has_data, $get_data),
+ @construct_closure($construct_closure),
+ @zeroed(()), // `()` means zero all fields not mentioned.
+ )
+ };
+ (
+ @this($($this:ident)?),
+ @typ($t:path),
+ @fields($($fields:tt)*),
+ @error($err:ty),
+ // Either `PinData` or `InitData`, `$use_data` should only be present in the `PinData`
+ // case.
+ @data($data:ident, $($use_data:ident)?),
+ // `HasPinData` or `HasInitData`.
+ @has_data($has_data:ident, $get_data:ident),
+ // `pin_init_from_closure` or `init_from_closure`.
+ @construct_closure($construct_closure:ident),
+ @munch_fields($ignore:tt $($rest:tt)*),
+ ) => {
+ $crate::__init_internal!(
+ @this($($this)?),
+ @typ($t),
+ @fields($($fields)*),
+ @error($err),
+ @data($data, $($use_data)?),
+ @has_data($has_data, $get_data),
+ @construct_closure($construct_closure),
+ @munch_fields($($rest)*),
+ )
+ };
+ (with_update_parsed:
+ @this($($this:ident)?),
+ @typ($t:path),
+ @fields($($fields:tt)*),
+ @error($err:ty),
+ // Either `PinData` or `InitData`, `$use_data` should only be present in the `PinData`
+ // case.
+ @data($data:ident, $($use_data:ident)?),
+ // `HasPinData` or `HasInitData`.
+ @has_data($has_data:ident, $get_data:ident),
+ // `pin_init_from_closure` or `init_from_closure`.
+ @construct_closure($construct_closure:ident),
+ @zeroed($($init_zeroed:expr)?),
+ ) => {{
+ // We do not want to allow arbitrary returns, so we declare this type as the `Ok` return
+ // type and shadow it later when we insert the arbitrary user code. That way there will be
+ // no possibility of returning without `unsafe`.
+ struct __InitOk;
+ // Get the data about fields from the supplied type.
+ let data = unsafe {
+ use $crate::init::__internal::$has_data;
+ // Here we abuse `paste!` to retokenize `$t`. Declarative macros have some internal
+ // information that is associated to already parsed fragments, so a path fragment
+ // cannot be used in this position. Doing the retokenization results in valid rust
+ // code.
+ ::kernel::macros::paste!($t::$get_data())
+ };
+ // Ensure that `data` really is of type `$data` and help with type inference:
+ let init = $crate::init::__internal::$data::make_closure::<_, __InitOk, $err>(
+ data,
+ move |slot| {
+ {
+ // Shadow the structure so it cannot be used to return early.
+ struct __InitOk;
+ // If `$init_zeroed` is present we should zero the slot now and not emit an
+ // error when fields are missing (since they will be zeroed). We also have to
+ // check that the type actually implements `Zeroable`.
+ $({
+ fn assert_zeroable<T: $crate::init::Zeroable>(_: *mut T) {}
+ // Ensure that the struct is indeed `Zeroable`.
+ assert_zeroable(slot);
+ // SAFETY: The type implements `Zeroable` by the check above.
+ unsafe { ::core::ptr::write_bytes(slot, 0, 1) };
+ $init_zeroed // This will be `()` if set.
+ })?
+ // Create the `this` so it can be referenced by the user inside of the
+ // expressions creating the individual fields.
+ $(let $this = unsafe { ::core::ptr::NonNull::new_unchecked(slot) };)?
+ // Initialize every field.
+ $crate::__init_internal!(init_slot($($use_data)?):
+ @data(data),
+ @slot(slot),
+ @guards(),
+ @munch_fields($($fields)*,),
+ );
+ // We use unreachable code to ensure that all fields have been mentioned exactly
+ // once, this struct initializer will still be type-checked and complain with a
+ // very natural error message if a field is forgotten/mentioned more than once.
+ #[allow(unreachable_code, clippy::diverging_sub_expression)]
+ let _ = || {
+ $crate::__init_internal!(make_initializer:
+ @slot(slot),
+ @type_name($t),
+ @munch_fields($($fields)*,),
+ @acc(),
+ );
+ };
+ }
+ Ok(__InitOk)
+ }
+ );
+ let init = move |slot| -> ::core::result::Result<(), $err> {
+ init(slot).map(|__InitOk| ())
+ };
+ let init = unsafe { $crate::init::$construct_closure::<_, $err>(init) };
+ init
+ }};
+ (init_slot($($use_data:ident)?):
+ @data($data:ident),
+ @slot($slot:ident),
+ @guards($($guards:ident,)*),
+ @munch_fields($(..Zeroable::zeroed())? $(,)?),
+ ) => {
+ // Endpoint of munching, no fields are left. If execution reaches this point, all fields
+ // have been initialized. Therefore we can now dismiss the guards by forgetting them.
+ $(::core::mem::forget($guards);)*
+ };
+ (init_slot($use_data:ident): // `use_data` is present, so we use the `data` to init fields.
+ @data($data:ident),
+ @slot($slot:ident),
+ @guards($($guards:ident,)*),
+ // In-place initialization syntax.
+ @munch_fields($field:ident <- $val:expr, $($rest:tt)*),
+ ) => {
+ let init = $val;
+ // Call the initializer.
+ //
+ // SAFETY: `slot` is valid, because we are inside of an initializer closure, we
+ // return when an error/panic occurs.
+ // We also use the `data` to require the correct trait (`Init` or `PinInit`) for `$field`.
+ unsafe { $data.$field(::core::ptr::addr_of_mut!((*$slot).$field), init)? };
+ // Create the drop guard:
+ //
+ // We rely on macro hygiene to make it impossible for users to access this local variable.
+ // We use `paste!` to create new hygiene for `$field`.
+ ::kernel::macros::paste! {
+ // SAFETY: We forget the guard later when initialization has succeeded.
+ let [<$field>] = unsafe {
+ $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
+ };
+
+ $crate::__init_internal!(init_slot($use_data):
+ @data($data),
+ @slot($slot),
+ @guards([<$field>], $($guards,)*),
+ @munch_fields($($rest)*),
+ );
+ }
+ };
+ (init_slot(): // No `use_data`, so we use `Init::__init` directly.
+ @data($data:ident),
+ @slot($slot:ident),
+ @guards($($guards:ident,)*),
+ // In-place initialization syntax.
+ @munch_fields($field:ident <- $val:expr, $($rest:tt)*),
+ ) => {
+ let init = $val;
+ // Call the initializer.
+ //
+ // SAFETY: `slot` is valid, because we are inside of an initializer closure, we
+ // return when an error/panic occurs.
+ unsafe { $crate::init::Init::__init(init, ::core::ptr::addr_of_mut!((*$slot).$field))? };
+ // Create the drop guard:
+ //
+ // We rely on macro hygiene to make it impossible for users to access this local variable.
+ // We use `paste!` to create new hygiene for `$field`.
+ ::kernel::macros::paste! {
+ // SAFETY: We forget the guard later when initialization has succeeded.
+ let [<$field>] = unsafe {
+ $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
+ };
+
+ $crate::__init_internal!(init_slot():
+ @data($data),
+ @slot($slot),
+ @guards([<$field>], $($guards,)*),
+ @munch_fields($($rest)*),
+ );
+ }
+ };
+ (init_slot($($use_data:ident)?):
+ @data($data:ident),
+ @slot($slot:ident),
+ @guards($($guards:ident,)*),
+ // Init by-value.
+ @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*),
+ ) => {
+ {
+ $(let $field = $val;)?
+ // Initialize the field.
+ //
+ // SAFETY: The memory at `slot` is uninitialized.
+ unsafe { ::core::ptr::write(::core::ptr::addr_of_mut!((*$slot).$field), $field) };
+ }
+ // Create the drop guard:
+ //
+ // We rely on macro hygiene to make it impossible for users to access this local variable.
+ // We use `paste!` to create new hygiene for `$field`.
+ ::kernel::macros::paste! {
+ // SAFETY: We forget the guard later when initialization has succeeded.
+ let [<$field>] = unsafe {
+ $crate::init::__internal::DropGuard::new(::core::ptr::addr_of_mut!((*$slot).$field))
+ };
+
+ $crate::__init_internal!(init_slot($($use_data)?):
+ @data($data),
+ @slot($slot),
+ @guards([<$field>], $($guards,)*),
+ @munch_fields($($rest)*),
+ );
+ }
+ };
+ (make_initializer:
+ @slot($slot:ident),
+ @type_name($t:path),
+ @munch_fields(..Zeroable::zeroed() $(,)?),
+ @acc($($acc:tt)*),
+ ) => {
+ // Endpoint, nothing more to munch, create the initializer. Since the users specified
+ // `..Zeroable::zeroed()`, the slot will already have been zeroed and all field that have
+ // not been overwritten are thus zero and initialized. We still check that all fields are
+ // actually accessible by using the struct update syntax ourselves.
+ // We are inside of a closure that is never executed and thus we can abuse `slot` to
+ // get the correct type inference here:
+ #[allow(unused_assignments)]
+ unsafe {
+ let mut zeroed = ::core::mem::zeroed();
+ // We have to use type inference here to make zeroed have the correct type. This does
+ // not get executed, so it has no effect.
+ ::core::ptr::write($slot, zeroed);
+ zeroed = ::core::mem::zeroed();
+ // Here we abuse `paste!` to retokenize `$t`. Declarative macros have some internal
+ // information that is associated to already parsed fragments, so a path fragment
+ // cannot be used in this position. Doing the retokenization results in valid rust
+ // code.
+ ::kernel::macros::paste!(
+ ::core::ptr::write($slot, $t {
+ $($acc)*
+ ..zeroed
+ });
+ );
+ }
+ };
+ (make_initializer:
+ @slot($slot:ident),
+ @type_name($t:path),
+ @munch_fields($(,)?),
+ @acc($($acc:tt)*),
+ ) => {
+ // Endpoint, nothing more to munch, create the initializer.
+ // Since we are in the closure that is never called, this will never get executed.
+ // We abuse `slot` to get the correct type inference here:
+ unsafe {
+ // Here we abuse `paste!` to retokenize `$t`. Declarative macros have some internal
+ // information that is associated to already parsed fragments, so a path fragment
+ // cannot be used in this position. Doing the retokenization results in valid rust
+ // code.
+ ::kernel::macros::paste!(
+ ::core::ptr::write($slot, $t {
+ $($acc)*
+ });
+ );
+ }
+ };
+ (make_initializer:
+ @slot($slot:ident),
+ @type_name($t:path),
+ @munch_fields($field:ident <- $val:expr, $($rest:tt)*),
+ @acc($($acc:tt)*),
+ ) => {
+ $crate::__init_internal!(make_initializer:
+ @slot($slot),
+ @type_name($t),
+ @munch_fields($($rest)*),
+ @acc($($acc)* $field: ::core::panic!(),),
+ );
+ };
+ (make_initializer:
+ @slot($slot:ident),
+ @type_name($t:path),
+ @munch_fields($field:ident $(: $val:expr)?, $($rest:tt)*),
+ @acc($($acc:tt)*),
+ ) => {
+ $crate::__init_internal!(make_initializer:
+ @slot($slot),
+ @type_name($t),
+ @munch_fields($($rest)*),
+ @acc($($acc)* $field: ::core::panic!(),),
+ );
+ };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __derive_zeroable {
+ (parse_input:
+ @sig(
+ $(#[$($struct_attr:tt)*])*
+ $vis:vis struct $name:ident
+ $(where $($whr:tt)*)?
+ ),
+ @impl_generics($($impl_generics:tt)*),
+ @ty_generics($($ty_generics:tt)*),
+ @body({
+ $(
+ $(#[$($field_attr:tt)*])*
+ $field:ident : $field_ty:ty
+ ),* $(,)?
+ }),
+ ) => {
+ // SAFETY: Every field type implements `Zeroable` and padding bytes may be zero.
+ #[automatically_derived]
+ unsafe impl<$($impl_generics)*> $crate::init::Zeroable for $name<$($ty_generics)*>
+ where
+ $($($whr)*)?
+ {}
+ const _: () = {
+ fn assert_zeroable<T: ?::core::marker::Sized + $crate::init::Zeroable>() {}
+ fn ensure_zeroable<$($impl_generics)*>()
+ where $($($whr)*)?
+ {
+ $(assert_zeroable::<$field_ty>();)*
+ }
+ };
+ };
+}
diff --git a/rust/kernel/ioctl.rs b/rust/kernel/ioctl.rs
index c49e1a8d3fd0..cfa7d080b531 100644
--- a/rust/kernel/ioctl.rs
+++ b/rust/kernel/ioctl.rs
@@ -1,8 +1,8 @@
// SPDX-License-Identifier: GPL-2.0
-//! ioctl() number definitions
+//! `ioctl()` number definitions.
//!
-//! C header: [`include/asm-generic/ioctl.h`](../../../../include/asm-generic/ioctl.h)
+//! C header: [`include/asm-generic/ioctl.h`](srctree/include/asm-generic/ioctl.h)
#![allow(non_snake_case)]
@@ -28,13 +28,13 @@ pub const fn _IO(ty: u32, nr: u32) -> u32 {
_IOC(uapi::_IOC_NONE, ty, nr, 0)
}
-/// Build an ioctl number for an read-only ioctl.
+/// Build an ioctl number for a read-only ioctl.
#[inline(always)]
pub const fn _IOR<T>(ty: u32, nr: u32) -> u32 {
_IOC(uapi::_IOC_READ, ty, nr, core::mem::size_of::<T>())
}
-/// Build an ioctl number for an write-only ioctl.
+/// Build an ioctl number for a write-only ioctl.
#[inline(always)]
pub const fn _IOW<T>(ty: u32, nr: u32) -> u32 {
_IOC(uapi::_IOC_WRITE, ty, nr, core::mem::size_of::<T>())
diff --git a/rust/kernel/kunit.rs b/rust/kernel/kunit.rs
new file mode 100644
index 000000000000..0ba77276ae7e
--- /dev/null
+++ b/rust/kernel/kunit.rs
@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! KUnit-based macros for Rust unit tests.
+//!
+//! C header: [`include/kunit/test.h`](srctree/include/kunit/test.h)
+//!
+//! Reference: <https://docs.kernel.org/dev-tools/kunit/index.html>
+
+use core::{ffi::c_void, fmt};
+
+/// Prints a KUnit error-level message.
+///
+/// Public but hidden since it should only be used from KUnit generated code.
+#[doc(hidden)]
+pub fn err(args: fmt::Arguments<'_>) {
+ // SAFETY: The format string is null-terminated and the `%pA` specifier matches the argument we
+ // are passing.
+ #[cfg(CONFIG_PRINTK)]
+ unsafe {
+ bindings::_printk(
+ b"\x013%pA\0".as_ptr() as _,
+ &args as *const _ as *const c_void,
+ );
+ }
+}
+
+/// Prints a KUnit info-level message.
+///
+/// Public but hidden since it should only be used from KUnit generated code.
+#[doc(hidden)]
+pub fn info(args: fmt::Arguments<'_>) {
+ // SAFETY: The format string is null-terminated and the `%pA` specifier matches the argument we
+ // are passing.
+ #[cfg(CONFIG_PRINTK)]
+ unsafe {
+ bindings::_printk(
+ b"\x016%pA\0".as_ptr() as _,
+ &args as *const _ as *const c_void,
+ );
+ }
+}
+
+/// Asserts that a boolean expression is `true` at runtime.
+///
+/// Public but hidden since it should only be used from generated tests.
+///
+/// Unlike the one in `core`, this one does not panic; instead, it is mapped to the KUnit
+/// facilities. See [`assert!`] for more details.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! kunit_assert {
+ ($name:literal, $file:literal, $diff:expr, $condition:expr $(,)?) => {
+ 'out: {
+ // Do nothing if the condition is `true`.
+ if $condition {
+ break 'out;
+ }
+
+ static FILE: &'static $crate::str::CStr = $crate::c_str!($file);
+ static LINE: i32 = core::line!() as i32 - $diff;
+ static CONDITION: &'static $crate::str::CStr = $crate::c_str!(stringify!($condition));
+
+ // SAFETY: FFI call without safety requirements.
+ let kunit_test = unsafe { $crate::bindings::kunit_get_current_test() };
+ if kunit_test.is_null() {
+ // The assertion failed but this task is not running a KUnit test, so we cannot call
+ // KUnit, but at least print an error to the kernel log. This may happen if this
+ // macro is called from an spawned thread in a test (see
+ // `scripts/rustdoc_test_gen.rs`) or if some non-test code calls this macro by
+ // mistake (it is hidden to prevent that).
+ //
+ // This mimics KUnit's failed assertion format.
+ $crate::kunit::err(format_args!(
+ " # {}: ASSERTION FAILED at {FILE}:{LINE}\n",
+ $name
+ ));
+ $crate::kunit::err(format_args!(
+ " Expected {CONDITION} to be true, but is false\n"
+ ));
+ $crate::kunit::err(format_args!(
+ " Failure not reported to KUnit since this is a non-KUnit task\n"
+ ));
+ break 'out;
+ }
+
+ #[repr(transparent)]
+ struct Location($crate::bindings::kunit_loc);
+
+ #[repr(transparent)]
+ struct UnaryAssert($crate::bindings::kunit_unary_assert);
+
+ // SAFETY: There is only a static instance and in that one the pointer field points to
+ // an immutable C string.
+ unsafe impl Sync for Location {}
+
+ // SAFETY: There is only a static instance and in that one the pointer field points to
+ // an immutable C string.
+ unsafe impl Sync for UnaryAssert {}
+
+ static LOCATION: Location = Location($crate::bindings::kunit_loc {
+ file: FILE.as_char_ptr(),
+ line: LINE,
+ });
+ static ASSERTION: UnaryAssert = UnaryAssert($crate::bindings::kunit_unary_assert {
+ assert: $crate::bindings::kunit_assert {},
+ condition: CONDITION.as_char_ptr(),
+ expected_true: true,
+ });
+
+ // SAFETY:
+ // - FFI call.
+ // - The `kunit_test` pointer is valid because we got it from
+ // `kunit_get_current_test()` and it was not null. This means we are in a KUnit
+ // test, and that the pointer can be passed to KUnit functions and assertions.
+ // - The string pointers (`file` and `condition` above) point to null-terminated
+ // strings since they are `CStr`s.
+ // - The function pointer (`format`) points to the proper function.
+ // - The pointers passed will remain valid since they point to `static`s.
+ // - The format string is allowed to be null.
+ // - There are, however, problems with this: first of all, this will end up stopping
+ // the thread, without running destructors. While that is problematic in itself,
+ // it is considered UB to have what is effectively a forced foreign unwind
+ // with `extern "C"` ABI. One could observe the stack that is now gone from
+ // another thread. We should avoid pinning stack variables to prevent library UB,
+ // too. For the moment, given that test failures are reported immediately before the
+ // next test runs, that test failures should be fixed and that KUnit is explicitly
+ // documented as not suitable for production environments, we feel it is reasonable.
+ unsafe {
+ $crate::bindings::__kunit_do_failed_assertion(
+ kunit_test,
+ core::ptr::addr_of!(LOCATION.0),
+ $crate::bindings::kunit_assert_type_KUNIT_ASSERTION,
+ core::ptr::addr_of!(ASSERTION.0.assert),
+ Some($crate::bindings::kunit_unary_assert_format),
+ core::ptr::null(),
+ );
+ }
+
+ // SAFETY: FFI call; the `test` pointer is valid because this hidden macro should only
+ // be called by the generated documentation tests which forward the test pointer given
+ // by KUnit.
+ unsafe {
+ $crate::bindings::__kunit_abort(kunit_test);
+ }
+ }
+ };
+}
+
+/// Asserts that two expressions are equal to each other (using [`PartialEq`]).
+///
+/// Public but hidden since it should only be used from generated tests.
+///
+/// Unlike the one in `core`, this one does not panic; instead, it is mapped to the KUnit
+/// facilities. See [`assert!`] for more details.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! kunit_assert_eq {
+ ($name:literal, $file:literal, $diff:expr, $left:expr, $right:expr $(,)?) => {{
+ // For the moment, we just forward to the expression assert because, for binary asserts,
+ // KUnit supports only a few types (e.g. integers).
+ $crate::kunit_assert!($name, $file, $diff, $left == $right);
+ }};
+}
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 85b261209977..6858e2f8a3ed 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -16,6 +16,7 @@
#![feature(coerce_unsized)]
#![feature(dispatch_from_dyn)]
#![feature(new_uninit)]
+#![feature(offset_of)]
#![feature(receiver_trait)]
#![feature(unsize)]
@@ -34,6 +35,10 @@ mod build_assert;
pub mod error;
pub mod init;
pub mod ioctl;
+#[cfg(CONFIG_KUNIT)]
+pub mod kunit;
+#[cfg(CONFIG_NET)]
+pub mod net;
pub mod prelude;
pub mod print;
mod static_assert;
@@ -42,7 +47,9 @@ pub mod std_vendor;
pub mod str;
pub mod sync;
pub mod task;
+pub mod time;
pub mod types;
+pub mod workqueue;
#[doc(hidden)]
pub use bindings;
@@ -58,7 +65,7 @@ const __LOG_PREFIX: &[u8] = b"rust_kernel\0";
/// The top level entrypoint to implementing a kernel module.
///
/// For any teardown or cleanup operations, your type may implement [`Drop`].
-pub trait Module: Sized + Sync {
+pub trait Module: Sized + Sync + Send {
/// Called at module initialization time.
///
/// Use this method to perform whatever setup or registration your module
@@ -70,7 +77,7 @@ pub trait Module: Sized + Sync {
/// Equivalent to `THIS_MODULE` in the C API.
///
-/// C header: `include/linux/export.h`
+/// C header: [`include/linux/export.h`](srctree/include/linux/export.h)
pub struct ThisModule(*mut bindings::module);
// SAFETY: `THIS_MODULE` may be used from all threads within a module.
@@ -93,7 +100,36 @@ fn panic(info: &core::panic::PanicInfo<'_>) -> ! {
pr_emerg!("{}\n", info);
// SAFETY: FFI call.
unsafe { bindings::BUG() };
- // Bindgen currently does not recognize `__noreturn` so `BUG` returns `()`
- // instead of `!`. See <https://github.com/rust-lang/rust-bindgen/issues/2094>.
- loop {}
+}
+
+/// Produces a pointer to an object from a pointer to one of its fields.
+///
+/// # Safety
+///
+/// The pointer passed to this macro, and the pointer returned by this macro, must both be in
+/// bounds of the same allocation.
+///
+/// # Examples
+///
+/// ```
+/// # use kernel::container_of;
+/// struct Test {
+/// a: u64,
+/// b: u32,
+/// }
+///
+/// let test = Test { a: 10, b: 20 };
+/// let b_ptr = &test.b;
+/// // SAFETY: The pointer points at the `b` field of a `Test`, so the resulting pointer will be
+/// // in-bounds of the same allocation as `b_ptr`.
+/// let test_alias = unsafe { container_of!(b_ptr, Test, b) };
+/// assert!(core::ptr::eq(&test, test_alias));
+/// ```
+#[macro_export]
+macro_rules! container_of {
+ ($ptr:expr, $type:ty, $($f:tt)*) => {{
+ let ptr = $ptr as *const _ as *const u8;
+ let offset: usize = ::core::mem::offset_of!($type, $($f)*);
+ ptr.sub(offset) as *const $type
+ }}
}
diff --git a/rust/kernel/net.rs b/rust/kernel/net.rs
new file mode 100644
index 000000000000..fe415cb369d3
--- /dev/null
+++ b/rust/kernel/net.rs
@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Networking.
+
+#[cfg(CONFIG_RUST_PHYLIB_ABSTRACTIONS)]
+pub mod phy;
diff --git a/rust/kernel/net/phy.rs b/rust/kernel/net/phy.rs
new file mode 100644
index 000000000000..265d0e1c1371
--- /dev/null
+++ b/rust/kernel/net/phy.rs
@@ -0,0 +1,905 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2023 FUJITA Tomonori <fujita.tomonori@gmail.com>
+
+//! Network PHY device.
+//!
+//! C headers: [`include/linux/phy.h`](srctree/include/linux/phy.h).
+
+use crate::{bindings, error::*, prelude::*, str::CStr, types::Opaque};
+
+use core::marker::PhantomData;
+
+/// PHY state machine states.
+///
+/// Corresponds to the kernel's [`enum phy_state`].
+///
+/// Some of PHY drivers access to the state of PHY's software state machine.
+///
+/// [`enum phy_state`]: srctree/include/linux/phy.h
+#[derive(PartialEq, Eq)]
+pub enum DeviceState {
+ /// PHY device and driver are not ready for anything.
+ Down,
+ /// PHY is ready to send and receive packets.
+ Ready,
+ /// PHY is up, but no polling or interrupts are done.
+ Halted,
+ /// PHY is up, but is in an error state.
+ Error,
+ /// PHY and attached device are ready to do work.
+ Up,
+ /// PHY is currently running.
+ Running,
+ /// PHY is up, but not currently plugged in.
+ NoLink,
+ /// PHY is performing a cable test.
+ CableTest,
+}
+
+/// A mode of Ethernet communication.
+///
+/// PHY drivers get duplex information from hardware and update the current state.
+pub enum DuplexMode {
+ /// PHY is in full-duplex mode.
+ Full,
+ /// PHY is in half-duplex mode.
+ Half,
+ /// PHY is in unknown duplex mode.
+ Unknown,
+}
+
+/// An instance of a PHY device.
+///
+/// Wraps the kernel's [`struct phy_device`].
+///
+/// A [`Device`] instance is created when a callback in [`Driver`] is executed. A PHY driver
+/// executes [`Driver`]'s methods during the callback.
+///
+/// # Invariants
+///
+/// Referencing a `phy_device` using this struct asserts that you are in
+/// a context where all methods defined on this struct are safe to call.
+///
+/// [`struct phy_device`]: srctree/include/linux/phy.h
+// During the calls to most functions in [`Driver`], the C side (`PHYLIB`) holds a lock that is
+// unique for every instance of [`Device`]. `PHYLIB` uses a different serialization technique for
+// [`Driver::resume`] and [`Driver::suspend`]: `PHYLIB` updates `phy_device`'s state with
+// the lock held, thus guaranteeing that [`Driver::resume`] has exclusive access to the instance.
+// [`Driver::resume`] and [`Driver::suspend`] also are called where only one thread can access
+// to the instance.
+#[repr(transparent)]
+pub struct Device(Opaque<bindings::phy_device>);
+
+impl Device {
+ /// Creates a new [`Device`] instance from a raw pointer.
+ ///
+ /// # Safety
+ ///
+ /// For the duration of 'a, the pointer must point at a valid `phy_device`,
+ /// and the caller must be in a context where all methods defined on this struct
+ /// are safe to call.
+ unsafe fn from_raw<'a>(ptr: *mut bindings::phy_device) -> &'a mut Self {
+ // CAST: `Self` is a `repr(transparent)` wrapper around `bindings::phy_device`.
+ let ptr = ptr.cast::<Self>();
+ // SAFETY: by the function requirements the pointer is valid and we have unique access for
+ // the duration of `'a`.
+ unsafe { &mut *ptr }
+ }
+
+ /// Gets the id of the PHY.
+ pub fn phy_id(&self) -> u32 {
+ let phydev = self.0.get();
+ // SAFETY: The struct invariant ensures that we may access
+ // this field without additional synchronization.
+ unsafe { (*phydev).phy_id }
+ }
+
+ /// Gets the state of PHY state machine states.
+ pub fn state(&self) -> DeviceState {
+ let phydev = self.0.get();
+ // SAFETY: The struct invariant ensures that we may access
+ // this field without additional synchronization.
+ let state = unsafe { (*phydev).state };
+ // TODO: this conversion code will be replaced with automatically generated code by bindgen
+ // when it becomes possible.
+ match state {
+ bindings::phy_state_PHY_DOWN => DeviceState::Down,
+ bindings::phy_state_PHY_READY => DeviceState::Ready,
+ bindings::phy_state_PHY_HALTED => DeviceState::Halted,
+ bindings::phy_state_PHY_ERROR => DeviceState::Error,
+ bindings::phy_state_PHY_UP => DeviceState::Up,
+ bindings::phy_state_PHY_RUNNING => DeviceState::Running,
+ bindings::phy_state_PHY_NOLINK => DeviceState::NoLink,
+ bindings::phy_state_PHY_CABLETEST => DeviceState::CableTest,
+ _ => DeviceState::Error,
+ }
+ }
+
+ /// Gets the current link state.
+ ///
+ /// It returns true if the link is up.
+ pub fn is_link_up(&self) -> bool {
+ const LINK_IS_UP: u64 = 1;
+ // TODO: the code to access to the bit field will be replaced with automatically
+ // generated code by bindgen when it becomes possible.
+ // SAFETY: The struct invariant ensures that we may access
+ // this field without additional synchronization.
+ let bit_field = unsafe { &(*self.0.get())._bitfield_1 };
+ bit_field.get(14, 1) == LINK_IS_UP
+ }
+
+ /// Gets the current auto-negotiation configuration.
+ ///
+ /// It returns true if auto-negotiation is enabled.
+ pub fn is_autoneg_enabled(&self) -> bool {
+ // TODO: the code to access to the bit field will be replaced with automatically
+ // generated code by bindgen when it becomes possible.
+ // SAFETY: The struct invariant ensures that we may access
+ // this field without additional synchronization.
+ let bit_field = unsafe { &(*self.0.get())._bitfield_1 };
+ bit_field.get(13, 1) == bindings::AUTONEG_ENABLE as u64
+ }
+
+ /// Gets the current auto-negotiation state.
+ ///
+ /// It returns true if auto-negotiation is completed.
+ pub fn is_autoneg_completed(&self) -> bool {
+ const AUTONEG_COMPLETED: u64 = 1;
+ // TODO: the code to access to the bit field will be replaced with automatically
+ // generated code by bindgen when it becomes possible.
+ // SAFETY: The struct invariant ensures that we may access
+ // this field without additional synchronization.
+ let bit_field = unsafe { &(*self.0.get())._bitfield_1 };
+ bit_field.get(15, 1) == AUTONEG_COMPLETED
+ }
+
+ /// Sets the speed of the PHY.
+ pub fn set_speed(&mut self, speed: u32) {
+ let phydev = self.0.get();
+ // SAFETY: The struct invariant ensures that we may access
+ // this field without additional synchronization.
+ unsafe { (*phydev).speed = speed as i32 };
+ }
+
+ /// Sets duplex mode.
+ pub fn set_duplex(&mut self, mode: DuplexMode) {
+ let phydev = self.0.get();
+ let v = match mode {
+ DuplexMode::Full => bindings::DUPLEX_FULL as i32,
+ DuplexMode::Half => bindings::DUPLEX_HALF as i32,
+ DuplexMode::Unknown => bindings::DUPLEX_UNKNOWN as i32,
+ };
+ // SAFETY: The struct invariant ensures that we may access
+ // this field without additional synchronization.
+ unsafe { (*phydev).duplex = v };
+ }
+
+ /// Reads a given C22 PHY register.
+ // This function reads a hardware register and updates the stats so takes `&mut self`.
+ pub fn read(&mut self, regnum: u16) -> Result<u16> {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So it's just an FFI call, open code of `phy_read()` with a valid `phy_device` pointer
+ // `phydev`.
+ let ret = unsafe {
+ bindings::mdiobus_read((*phydev).mdio.bus, (*phydev).mdio.addr, regnum.into())
+ };
+ if ret < 0 {
+ Err(Error::from_errno(ret))
+ } else {
+ Ok(ret as u16)
+ }
+ }
+
+ /// Writes a given C22 PHY register.
+ pub fn write(&mut self, regnum: u16, val: u16) -> Result {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So it's just an FFI call, open code of `phy_write()` with a valid `phy_device` pointer
+ // `phydev`.
+ to_result(unsafe {
+ bindings::mdiobus_write((*phydev).mdio.bus, (*phydev).mdio.addr, regnum.into(), val)
+ })
+ }
+
+ /// Reads a paged register.
+ pub fn read_paged(&mut self, page: u16, regnum: u16) -> Result<u16> {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So it's just an FFI call.
+ let ret = unsafe { bindings::phy_read_paged(phydev, page.into(), regnum.into()) };
+ if ret < 0 {
+ Err(Error::from_errno(ret))
+ } else {
+ Ok(ret as u16)
+ }
+ }
+
+ /// Resolves the advertisements into PHY settings.
+ pub fn resolve_aneg_linkmode(&mut self) {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So it's just an FFI call.
+ unsafe { bindings::phy_resolve_aneg_linkmode(phydev) };
+ }
+
+ /// Executes software reset the PHY via `BMCR_RESET` bit.
+ pub fn genphy_soft_reset(&mut self) -> Result {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So it's just an FFI call.
+ to_result(unsafe { bindings::genphy_soft_reset(phydev) })
+ }
+
+ /// Initializes the PHY.
+ pub fn init_hw(&mut self) -> Result {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So it's just an FFI call.
+ to_result(unsafe { bindings::phy_init_hw(phydev) })
+ }
+
+ /// Starts auto-negotiation.
+ pub fn start_aneg(&mut self) -> Result {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So it's just an FFI call.
+ to_result(unsafe { bindings::_phy_start_aneg(phydev) })
+ }
+
+ /// Resumes the PHY via `BMCR_PDOWN` bit.
+ pub fn genphy_resume(&mut self) -> Result {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So it's just an FFI call.
+ to_result(unsafe { bindings::genphy_resume(phydev) })
+ }
+
+ /// Suspends the PHY via `BMCR_PDOWN` bit.
+ pub fn genphy_suspend(&mut self) -> Result {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So it's just an FFI call.
+ to_result(unsafe { bindings::genphy_suspend(phydev) })
+ }
+
+ /// Checks the link status and updates current link state.
+ pub fn genphy_read_status(&mut self) -> Result<u16> {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So it's just an FFI call.
+ let ret = unsafe { bindings::genphy_read_status(phydev) };
+ if ret < 0 {
+ Err(Error::from_errno(ret))
+ } else {
+ Ok(ret as u16)
+ }
+ }
+
+ /// Updates the link status.
+ pub fn genphy_update_link(&mut self) -> Result {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So it's just an FFI call.
+ to_result(unsafe { bindings::genphy_update_link(phydev) })
+ }
+
+ /// Reads link partner ability.
+ pub fn genphy_read_lpa(&mut self) -> Result {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So it's just an FFI call.
+ to_result(unsafe { bindings::genphy_read_lpa(phydev) })
+ }
+
+ /// Reads PHY abilities.
+ pub fn genphy_read_abilities(&mut self) -> Result {
+ let phydev = self.0.get();
+ // SAFETY: `phydev` is pointing to a valid object by the type invariant of `Self`.
+ // So it's just an FFI call.
+ to_result(unsafe { bindings::genphy_read_abilities(phydev) })
+ }
+}
+
+/// Defines certain other features this PHY supports (like interrupts).
+///
+/// These flag values are used in [`Driver::FLAGS`].
+pub mod flags {
+ /// PHY is internal.
+ pub const IS_INTERNAL: u32 = bindings::PHY_IS_INTERNAL;
+ /// PHY needs to be reset after the refclk is enabled.
+ pub const RST_AFTER_CLK_EN: u32 = bindings::PHY_RST_AFTER_CLK_EN;
+ /// Polling is used to detect PHY status changes.
+ pub const POLL_CABLE_TEST: u32 = bindings::PHY_POLL_CABLE_TEST;
+ /// Don't suspend.
+ pub const ALWAYS_CALL_SUSPEND: u32 = bindings::PHY_ALWAYS_CALL_SUSPEND;
+}
+
+/// An adapter for the registration of a PHY driver.
+struct Adapter<T: Driver> {
+ _p: PhantomData<T>,
+}
+
+impl<T: Driver> Adapter<T> {
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn soft_reset_callback(
+ phydev: *mut bindings::phy_device,
+ ) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: This callback is called only in contexts
+ // where we hold `phy_device->lock`, so the accessors on
+ // `Device` are okay to call.
+ let dev = unsafe { Device::from_raw(phydev) };
+ T::soft_reset(dev)?;
+ Ok(0)
+ })
+ }
+
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn get_features_callback(
+ phydev: *mut bindings::phy_device,
+ ) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: This callback is called only in contexts
+ // where we hold `phy_device->lock`, so the accessors on
+ // `Device` are okay to call.
+ let dev = unsafe { Device::from_raw(phydev) };
+ T::get_features(dev)?;
+ Ok(0)
+ })
+ }
+
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn suspend_callback(phydev: *mut bindings::phy_device) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: The C core code ensures that the accessors on
+ // `Device` are okay to call even though `phy_device->lock`
+ // might not be held.
+ let dev = unsafe { Device::from_raw(phydev) };
+ T::suspend(dev)?;
+ Ok(0)
+ })
+ }
+
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn resume_callback(phydev: *mut bindings::phy_device) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: The C core code ensures that the accessors on
+ // `Device` are okay to call even though `phy_device->lock`
+ // might not be held.
+ let dev = unsafe { Device::from_raw(phydev) };
+ T::resume(dev)?;
+ Ok(0)
+ })
+ }
+
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn config_aneg_callback(
+ phydev: *mut bindings::phy_device,
+ ) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: This callback is called only in contexts
+ // where we hold `phy_device->lock`, so the accessors on
+ // `Device` are okay to call.
+ let dev = unsafe { Device::from_raw(phydev) };
+ T::config_aneg(dev)?;
+ Ok(0)
+ })
+ }
+
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn read_status_callback(
+ phydev: *mut bindings::phy_device,
+ ) -> core::ffi::c_int {
+ from_result(|| {
+ // SAFETY: This callback is called only in contexts
+ // where we hold `phy_device->lock`, so the accessors on
+ // `Device` are okay to call.
+ let dev = unsafe { Device::from_raw(phydev) };
+ T::read_status(dev)?;
+ Ok(0)
+ })
+ }
+
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn match_phy_device_callback(
+ phydev: *mut bindings::phy_device,
+ ) -> core::ffi::c_int {
+ // SAFETY: This callback is called only in contexts
+ // where we hold `phy_device->lock`, so the accessors on
+ // `Device` are okay to call.
+ let dev = unsafe { Device::from_raw(phydev) };
+ T::match_phy_device(dev) as i32
+ }
+
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn read_mmd_callback(
+ phydev: *mut bindings::phy_device,
+ devnum: i32,
+ regnum: u16,
+ ) -> i32 {
+ from_result(|| {
+ // SAFETY: This callback is called only in contexts
+ // where we hold `phy_device->lock`, so the accessors on
+ // `Device` are okay to call.
+ let dev = unsafe { Device::from_raw(phydev) };
+ // CAST: the C side verifies devnum < 32.
+ let ret = T::read_mmd(dev, devnum as u8, regnum)?;
+ Ok(ret.into())
+ })
+ }
+
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn write_mmd_callback(
+ phydev: *mut bindings::phy_device,
+ devnum: i32,
+ regnum: u16,
+ val: u16,
+ ) -> i32 {
+ from_result(|| {
+ // SAFETY: This callback is called only in contexts
+ // where we hold `phy_device->lock`, so the accessors on
+ // `Device` are okay to call.
+ let dev = unsafe { Device::from_raw(phydev) };
+ T::write_mmd(dev, devnum as u8, regnum, val)?;
+ Ok(0)
+ })
+ }
+
+ /// # Safety
+ ///
+ /// `phydev` must be passed by the corresponding callback in `phy_driver`.
+ unsafe extern "C" fn link_change_notify_callback(phydev: *mut bindings::phy_device) {
+ // SAFETY: This callback is called only in contexts
+ // where we hold `phy_device->lock`, so the accessors on
+ // `Device` are okay to call.
+ let dev = unsafe { Device::from_raw(phydev) };
+ T::link_change_notify(dev);
+ }
+}
+
+/// Driver structure for a particular PHY type.
+///
+/// Wraps the kernel's [`struct phy_driver`].
+/// This is used to register a driver for a particular PHY type with the kernel.
+///
+/// # Invariants
+///
+/// `self.0` is always in a valid state.
+///
+/// [`struct phy_driver`]: srctree/include/linux/phy.h
+#[repr(transparent)]
+pub struct DriverVTable(Opaque<bindings::phy_driver>);
+
+// SAFETY: `DriverVTable` doesn't expose any &self method to access internal data, so it's safe to
+// share `&DriverVTable` across execution context boundries.
+unsafe impl Sync for DriverVTable {}
+
+/// Creates a [`DriverVTable`] instance from [`Driver`].
+///
+/// This is used by [`module_phy_driver`] macro to create a static array of `phy_driver`.
+///
+/// [`module_phy_driver`]: crate::module_phy_driver
+pub const fn create_phy_driver<T: Driver>() -> DriverVTable {
+ // INVARIANT: All the fields of `struct phy_driver` are initialized properly.
+ DriverVTable(Opaque::new(bindings::phy_driver {
+ name: T::NAME.as_char_ptr().cast_mut(),
+ flags: T::FLAGS,
+ phy_id: T::PHY_DEVICE_ID.id,
+ phy_id_mask: T::PHY_DEVICE_ID.mask_as_int(),
+ soft_reset: if T::HAS_SOFT_RESET {
+ Some(Adapter::<T>::soft_reset_callback)
+ } else {
+ None
+ },
+ get_features: if T::HAS_GET_FEATURES {
+ Some(Adapter::<T>::get_features_callback)
+ } else {
+ None
+ },
+ match_phy_device: if T::HAS_MATCH_PHY_DEVICE {
+ Some(Adapter::<T>::match_phy_device_callback)
+ } else {
+ None
+ },
+ suspend: if T::HAS_SUSPEND {
+ Some(Adapter::<T>::suspend_callback)
+ } else {
+ None
+ },
+ resume: if T::HAS_RESUME {
+ Some(Adapter::<T>::resume_callback)
+ } else {
+ None
+ },
+ config_aneg: if T::HAS_CONFIG_ANEG {
+ Some(Adapter::<T>::config_aneg_callback)
+ } else {
+ None
+ },
+ read_status: if T::HAS_READ_STATUS {
+ Some(Adapter::<T>::read_status_callback)
+ } else {
+ None
+ },
+ read_mmd: if T::HAS_READ_MMD {
+ Some(Adapter::<T>::read_mmd_callback)
+ } else {
+ None
+ },
+ write_mmd: if T::HAS_WRITE_MMD {
+ Some(Adapter::<T>::write_mmd_callback)
+ } else {
+ None
+ },
+ link_change_notify: if T::HAS_LINK_CHANGE_NOTIFY {
+ Some(Adapter::<T>::link_change_notify_callback)
+ } else {
+ None
+ },
+ // SAFETY: The rest is zeroed out to initialize `struct phy_driver`,
+ // sets `Option<&F>` to be `None`.
+ ..unsafe { core::mem::MaybeUninit::<bindings::phy_driver>::zeroed().assume_init() }
+ }))
+}
+
+/// Driver implementation for a particular PHY type.
+///
+/// This trait is used to create a [`DriverVTable`].
+#[vtable]
+pub trait Driver {
+ /// Defines certain other features this PHY supports.
+ /// It is a combination of the flags in the [`flags`] module.
+ const FLAGS: u32 = 0;
+
+ /// The friendly name of this PHY type.
+ const NAME: &'static CStr;
+
+ /// This driver only works for PHYs with IDs which match this field.
+ /// The default id and mask are zero.
+ const PHY_DEVICE_ID: DeviceId = DeviceId::new_with_custom_mask(0, 0);
+
+ /// Issues a PHY software reset.
+ fn soft_reset(_dev: &mut Device) -> Result {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Probes the hardware to determine what abilities it has.
+ fn get_features(_dev: &mut Device) -> Result {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Returns true if this is a suitable driver for the given phydev.
+ /// If not implemented, matching is based on [`Driver::PHY_DEVICE_ID`].
+ fn match_phy_device(_dev: &Device) -> bool {
+ false
+ }
+
+ /// Configures the advertisement and resets auto-negotiation
+ /// if auto-negotiation is enabled.
+ fn config_aneg(_dev: &mut Device) -> Result {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Determines the negotiated speed and duplex.
+ fn read_status(_dev: &mut Device) -> Result<u16> {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Suspends the hardware, saving state if needed.
+ fn suspend(_dev: &mut Device) -> Result {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Resumes the hardware, restoring state if needed.
+ fn resume(_dev: &mut Device) -> Result {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Overrides the default MMD read function for reading a MMD register.
+ fn read_mmd(_dev: &mut Device, _devnum: u8, _regnum: u16) -> Result<u16> {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Overrides the default MMD write function for writing a MMD register.
+ fn write_mmd(_dev: &mut Device, _devnum: u8, _regnum: u16, _val: u16) -> Result {
+ kernel::build_error(VTABLE_DEFAULT_ERROR)
+ }
+
+ /// Callback for notification of link change.
+ fn link_change_notify(_dev: &mut Device) {}
+}
+
+/// Registration structure for PHY drivers.
+///
+/// Registers [`DriverVTable`] instances with the kernel. They will be unregistered when dropped.
+///
+/// # Invariants
+///
+/// The `drivers` slice are currently registered to the kernel via `phy_drivers_register`.
+pub struct Registration {
+ drivers: Pin<&'static mut [DriverVTable]>,
+}
+
+// SAFETY: The only action allowed in a `Registration` instance is dropping it, which is safe to do
+// from any thread because `phy_drivers_unregister` can be called from any thread context.
+unsafe impl Send for Registration {}
+
+impl Registration {
+ /// Registers a PHY driver.
+ pub fn register(
+ module: &'static crate::ThisModule,
+ drivers: Pin<&'static mut [DriverVTable]>,
+ ) -> Result<Self> {
+ if drivers.is_empty() {
+ return Err(code::EINVAL);
+ }
+ // SAFETY: The type invariants of [`DriverVTable`] ensure that all elements of
+ // the `drivers` slice are initialized properly. `drivers` will not be moved.
+ // So it's just an FFI call.
+ to_result(unsafe {
+ bindings::phy_drivers_register(drivers[0].0.get(), drivers.len().try_into()?, module.0)
+ })?;
+ // INVARIANT: The `drivers` slice is successfully registered to the kernel via `phy_drivers_register`.
+ Ok(Registration { drivers })
+ }
+}
+
+impl Drop for Registration {
+ fn drop(&mut self) {
+ // SAFETY: The type invariants guarantee that `self.drivers` is valid.
+ // So it's just an FFI call.
+ unsafe {
+ bindings::phy_drivers_unregister(self.drivers[0].0.get(), self.drivers.len() as i32)
+ };
+ }
+}
+
+/// An identifier for PHY devices on an MDIO/MII bus.
+///
+/// Represents the kernel's `struct mdio_device_id`. This is used to find an appropriate
+/// PHY driver.
+pub struct DeviceId {
+ id: u32,
+ mask: DeviceMask,
+}
+
+impl DeviceId {
+ /// Creates a new instance with the exact match mask.
+ pub const fn new_with_exact_mask(id: u32) -> Self {
+ DeviceId {
+ id,
+ mask: DeviceMask::Exact,
+ }
+ }
+
+ /// Creates a new instance with the model match mask.
+ pub const fn new_with_model_mask(id: u32) -> Self {
+ DeviceId {
+ id,
+ mask: DeviceMask::Model,
+ }
+ }
+
+ /// Creates a new instance with the vendor match mask.
+ pub const fn new_with_vendor_mask(id: u32) -> Self {
+ DeviceId {
+ id,
+ mask: DeviceMask::Vendor,
+ }
+ }
+
+ /// Creates a new instance with a custom match mask.
+ pub const fn new_with_custom_mask(id: u32, mask: u32) -> Self {
+ DeviceId {
+ id,
+ mask: DeviceMask::Custom(mask),
+ }
+ }
+
+ /// Creates a new instance from [`Driver`].
+ pub const fn new_with_driver<T: Driver>() -> Self {
+ T::PHY_DEVICE_ID
+ }
+
+ /// Get a `mask` as u32.
+ pub const fn mask_as_int(&self) -> u32 {
+ self.mask.as_int()
+ }
+
+ // macro use only
+ #[doc(hidden)]
+ pub const fn mdio_device_id(&self) -> bindings::mdio_device_id {
+ bindings::mdio_device_id {
+ phy_id: self.id,
+ phy_id_mask: self.mask.as_int(),
+ }
+ }
+}
+
+enum DeviceMask {
+ Exact,
+ Model,
+ Vendor,
+ Custom(u32),
+}
+
+impl DeviceMask {
+ const MASK_EXACT: u32 = !0;
+ const MASK_MODEL: u32 = !0 << 4;
+ const MASK_VENDOR: u32 = !0 << 10;
+
+ const fn as_int(&self) -> u32 {
+ match self {
+ DeviceMask::Exact => Self::MASK_EXACT,
+ DeviceMask::Model => Self::MASK_MODEL,
+ DeviceMask::Vendor => Self::MASK_VENDOR,
+ DeviceMask::Custom(mask) => *mask,
+ }
+ }
+}
+
+/// Declares a kernel module for PHYs drivers.
+///
+/// This creates a static array of kernel's `struct phy_driver` and registers it.
+/// This also corresponds to the kernel's `MODULE_DEVICE_TABLE` macro, which embeds the information
+/// for module loading into the module binary file. Every driver needs an entry in `device_table`.
+///
+/// # Examples
+///
+/// ```
+/// # mod module_phy_driver_sample {
+/// use kernel::c_str;
+/// use kernel::net::phy::{self, DeviceId};
+/// use kernel::prelude::*;
+///
+/// kernel::module_phy_driver! {
+/// drivers: [PhySample],
+/// device_table: [
+/// DeviceId::new_with_driver::<PhySample>()
+/// ],
+/// name: "rust_sample_phy",
+/// author: "Rust for Linux Contributors",
+/// description: "Rust sample PHYs driver",
+/// license: "GPL",
+/// }
+///
+/// struct PhySample;
+///
+/// #[vtable]
+/// impl phy::Driver for PhySample {
+/// const NAME: &'static CStr = c_str!("PhySample");
+/// const PHY_DEVICE_ID: phy::DeviceId = phy::DeviceId::new_with_exact_mask(0x00000001);
+/// }
+/// # }
+/// ```
+///
+/// This expands to the following code:
+///
+/// ```ignore
+/// use kernel::c_str;
+/// use kernel::net::phy::{self, DeviceId};
+/// use kernel::prelude::*;
+///
+/// struct Module {
+/// _reg: ::kernel::net::phy::Registration,
+/// }
+///
+/// module! {
+/// type: Module,
+/// name: "rust_sample_phy",
+/// author: "Rust for Linux Contributors",
+/// description: "Rust sample PHYs driver",
+/// license: "GPL",
+/// }
+///
+/// struct PhySample;
+///
+/// #[vtable]
+/// impl phy::Driver for PhySample {
+/// const NAME: &'static CStr = c_str!("PhySample");
+/// const PHY_DEVICE_ID: phy::DeviceId = phy::DeviceId::new_with_exact_mask(0x00000001);
+/// }
+///
+/// const _: () = {
+/// static mut DRIVERS: [::kernel::net::phy::DriverVTable; 1] =
+/// [::kernel::net::phy::create_phy_driver::<PhySample>()];
+///
+/// impl ::kernel::Module for Module {
+/// fn init(module: &'static ThisModule) -> Result<Self> {
+/// let drivers = unsafe { &mut DRIVERS };
+/// let mut reg = ::kernel::net::phy::Registration::register(
+/// module,
+/// ::core::pin::Pin::static_mut(drivers),
+/// )?;
+/// Ok(Module { _reg: reg })
+/// }
+/// }
+/// };
+///
+/// #[cfg(MODULE)]
+/// #[no_mangle]
+/// static __mod_mdio__phydev_device_table: [::kernel::bindings::mdio_device_id; 2] = [
+/// ::kernel::bindings::mdio_device_id {
+/// phy_id: 0x00000001,
+/// phy_id_mask: 0xffffffff,
+/// },
+/// ::kernel::bindings::mdio_device_id {
+/// phy_id: 0,
+/// phy_id_mask: 0,
+/// },
+/// ];
+/// ```
+#[macro_export]
+macro_rules! module_phy_driver {
+ (@replace_expr $_t:tt $sub:expr) => {$sub};
+
+ (@count_devices $($x:expr),*) => {
+ 0usize $(+ $crate::module_phy_driver!(@replace_expr $x 1usize))*
+ };
+
+ (@device_table [$($dev:expr),+]) => {
+ // SAFETY: C will not read off the end of this constant since the last element is zero.
+ #[cfg(MODULE)]
+ #[no_mangle]
+ static __mod_mdio__phydev_device_table: [$crate::bindings::mdio_device_id;
+ $crate::module_phy_driver!(@count_devices $($dev),+) + 1] = [
+ $($dev.mdio_device_id()),+,
+ $crate::bindings::mdio_device_id {
+ phy_id: 0,
+ phy_id_mask: 0
+ }
+ ];
+ };
+
+ (drivers: [$($driver:ident),+ $(,)?], device_table: [$($dev:expr),+ $(,)?], $($f:tt)*) => {
+ struct Module {
+ _reg: $crate::net::phy::Registration,
+ }
+
+ $crate::prelude::module! {
+ type: Module,
+ $($f)*
+ }
+
+ const _: () = {
+ static mut DRIVERS: [$crate::net::phy::DriverVTable;
+ $crate::module_phy_driver!(@count_devices $($driver),+)] =
+ [$($crate::net::phy::create_phy_driver::<$driver>()),+];
+
+ impl $crate::Module for Module {
+ fn init(module: &'static ThisModule) -> Result<Self> {
+ // SAFETY: The anonymous constant guarantees that nobody else can access
+ // the `DRIVERS` static. The array is used only in the C side.
+ let drivers = unsafe { &mut DRIVERS };
+ let mut reg = $crate::net::phy::Registration::register(
+ module,
+ ::core::pin::Pin::static_mut(drivers),
+ )?;
+ Ok(Module { _reg: reg })
+ }
+ }
+ };
+
+ $crate::module_phy_driver!(@device_table [$($dev),+]);
+ }
+}
diff --git a/rust/kernel/prelude.rs b/rust/kernel/prelude.rs
index c28587d68ebc..ae21600970b3 100644
--- a/rust/kernel/prelude.rs
+++ b/rust/kernel/prelude.rs
@@ -18,7 +18,7 @@ pub use core::pin::Pin;
pub use alloc::{boxed::Box, vec::Vec};
#[doc(no_inline)]
-pub use macros::{module, pin_data, pinned_drop, vtable};
+pub use macros::{module, pin_data, pinned_drop, vtable, Zeroable};
pub use super::build_assert;
diff --git a/rust/kernel/print.rs b/rust/kernel/print.rs
index 8009184bf6d7..9b13aca832c2 100644
--- a/rust/kernel/print.rs
+++ b/rust/kernel/print.rs
@@ -2,7 +2,7 @@
//! Printing facilities.
//!
-//! C header: [`include/linux/printk.h`](../../../../include/linux/printk.h)
+//! C header: [`include/linux/printk.h`](srctree/include/linux/printk.h)
//!
//! Reference: <https://www.kernel.org/doc/html/latest/core-api/printk-basics.html>
@@ -48,7 +48,7 @@ pub mod format_strings {
/// The format string is always the same for a given level, i.e. for a
/// given `prefix`, which are the kernel's `KERN_*` constants.
///
- /// [`_printk`]: ../../../../include/linux/printk.h
+ /// [`_printk`]: srctree/include/linux/printk.h
const fn generate(is_cont: bool, prefix: &[u8; 3]) -> [u8; LENGTH] {
// Ensure the `KERN_*` macros are what we expect.
assert!(prefix[0] == b'\x01');
@@ -97,7 +97,7 @@ pub mod format_strings {
/// The format string must be one of the ones in [`format_strings`], and
/// the module name must be null-terminated.
///
-/// [`_printk`]: ../../../../include/linux/_printk.h
+/// [`_printk`]: srctree/include/linux/_printk.h
#[doc(hidden)]
#[cfg_attr(not(CONFIG_PRINTK), allow(unused_variables))]
pub unsafe fn call_printk(
@@ -120,7 +120,7 @@ pub unsafe fn call_printk(
///
/// Public but hidden since it should only be used from public macros.
///
-/// [`_printk`]: ../../../../include/linux/printk.h
+/// [`_printk`]: srctree/include/linux/printk.h
#[doc(hidden)]
#[cfg_attr(not(CONFIG_PRINTK), allow(unused_variables))]
pub fn call_printk_cont(args: fmt::Arguments<'_>) {
@@ -399,6 +399,7 @@ macro_rules! pr_debug (
/// Mimics the interface of [`std::print!`]. See [`core::fmt`] and
/// `alloc::format!` for information about the formatting syntax.
///
+/// [`pr_info!`]: crate::pr_info!
/// [`pr_cont`]: https://www.kernel.org/doc/html/latest/core-api/printk-basics.html#c.pr_cont
/// [`std::print!`]: https://doc.rust-lang.org/std/macro.print.html
///
diff --git a/rust/kernel/str.rs b/rust/kernel/str.rs
index c9dd3bf59e34..925ced8fdc61 100644
--- a/rust/kernel/str.rs
+++ b/rust/kernel/str.rs
@@ -13,9 +13,102 @@ use crate::{
};
/// Byte string without UTF-8 validity guarantee.
-///
-/// `BStr` is simply an alias to `[u8]`, but has a more evident semantical meaning.
-pub type BStr = [u8];
+#[repr(transparent)]
+pub struct BStr([u8]);
+
+impl BStr {
+ /// Returns the length of this string.
+ #[inline]
+ pub const fn len(&self) -> usize {
+ self.0.len()
+ }
+
+ /// Returns `true` if the string is empty.
+ #[inline]
+ pub const fn is_empty(&self) -> bool {
+ self.len() == 0
+ }
+
+ /// Creates a [`BStr`] from a `[u8]`.
+ #[inline]
+ pub const fn from_bytes(bytes: &[u8]) -> &Self {
+ // SAFETY: `BStr` is transparent to `[u8]`.
+ unsafe { &*(bytes as *const [u8] as *const BStr) }
+ }
+}
+
+impl fmt::Display for BStr {
+ /// Formats printable ASCII characters, escaping the rest.
+ ///
+ /// ```
+ /// # use kernel::{fmt, b_str, str::{BStr, CString}};
+ /// let ascii = b_str!("Hello, BStr!");
+ /// let s = CString::try_from_fmt(fmt!("{}", ascii)).unwrap();
+ /// assert_eq!(s.as_bytes(), "Hello, BStr!".as_bytes());
+ ///
+ /// let non_ascii = b_str!("🦀");
+ /// let s = CString::try_from_fmt(fmt!("{}", non_ascii)).unwrap();
+ /// assert_eq!(s.as_bytes(), "\\xf0\\x9f\\xa6\\x80".as_bytes());
+ /// ```
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ for &b in &self.0 {
+ match b {
+ // Common escape codes.
+ b'\t' => f.write_str("\\t")?,
+ b'\n' => f.write_str("\\n")?,
+ b'\r' => f.write_str("\\r")?,
+ // Printable characters.
+ 0x20..=0x7e => f.write_char(b as char)?,
+ _ => write!(f, "\\x{:02x}", b)?,
+ }
+ }
+ Ok(())
+ }
+}
+
+impl fmt::Debug for BStr {
+ /// Formats printable ASCII characters with a double quote on either end,
+ /// escaping the rest.
+ ///
+ /// ```
+ /// # use kernel::{fmt, b_str, str::{BStr, CString}};
+ /// // Embedded double quotes are escaped.
+ /// let ascii = b_str!("Hello, \"BStr\"!");
+ /// let s = CString::try_from_fmt(fmt!("{:?}", ascii)).unwrap();
+ /// assert_eq!(s.as_bytes(), "\"Hello, \\\"BStr\\\"!\"".as_bytes());
+ ///
+ /// let non_ascii = b_str!("😺");
+ /// let s = CString::try_from_fmt(fmt!("{:?}", non_ascii)).unwrap();
+ /// assert_eq!(s.as_bytes(), "\"\\xf0\\x9f\\x98\\xba\"".as_bytes());
+ /// ```
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ f.write_char('"')?;
+ for &b in &self.0 {
+ match b {
+ // Common escape codes.
+ b'\t' => f.write_str("\\t")?,
+ b'\n' => f.write_str("\\n")?,
+ b'\r' => f.write_str("\\r")?,
+ // String escape characters.
+ b'\"' => f.write_str("\\\"")?,
+ b'\\' => f.write_str("\\\\")?,
+ // Printable characters.
+ 0x20..=0x7e => f.write_char(b as char)?,
+ _ => write!(f, "\\x{:02x}", b)?,
+ }
+ }
+ f.write_char('"')
+ }
+}
+
+impl Deref for BStr {
+ type Target = [u8];
+
+ #[inline]
+ fn deref(&self) -> &Self::Target {
+ &self.0
+ }
+}
/// Creates a new [`BStr`] from a string literal.
///
@@ -33,7 +126,7 @@ pub type BStr = [u8];
macro_rules! b_str {
($str:literal) => {{
const S: &'static str = $str;
- const C: &'static $crate::str::BStr = S.as_bytes();
+ const C: &'static $crate::str::BStr = $crate::str::BStr::from_bytes(S.as_bytes());
C
}};
}
@@ -149,13 +242,13 @@ impl CStr {
self.0.as_ptr() as _
}
- /// Convert the string to a byte slice without the trailing 0 byte.
+ /// Convert the string to a byte slice without the trailing `NUL` byte.
#[inline]
pub fn as_bytes(&self) -> &[u8] {
&self.0[..self.len()]
}
- /// Convert the string to a byte slice containing the trailing 0 byte.
+ /// Convert the string to a byte slice containing the trailing `NUL` byte.
#[inline]
pub const fn as_bytes_with_nul(&self) -> &[u8] {
&self.0
@@ -191,9 +284,9 @@ impl CStr {
/// ```
/// # use kernel::c_str;
/// # use kernel::str::CStr;
+ /// let bar = c_str!("ツ");
/// // SAFETY: String literals are guaranteed to be valid UTF-8
/// // by the Rust compiler.
- /// let bar = c_str!("ツ");
/// assert_eq!(unsafe { bar.as_str_unchecked() }, "ツ");
/// ```
#[inline]
@@ -213,6 +306,7 @@ impl fmt::Display for CStr {
///
/// ```
/// # use kernel::c_str;
+ /// # use kernel::fmt;
/// # use kernel::str::CStr;
/// # use kernel::str::CString;
/// let penguin = c_str!("🐧");
@@ -241,6 +335,7 @@ impl fmt::Debug for CStr {
///
/// ```
/// # use kernel::c_str;
+ /// # use kernel::fmt;
/// # use kernel::str::CStr;
/// # use kernel::str::CString;
/// let penguin = c_str!("🐧");
@@ -269,7 +364,7 @@ impl fmt::Debug for CStr {
impl AsRef<BStr> for CStr {
#[inline]
fn as_ref(&self) -> &BStr {
- self.as_bytes()
+ BStr::from_bytes(self.as_bytes())
}
}
@@ -278,7 +373,7 @@ impl Deref for CStr {
#[inline]
fn deref(&self) -> &Self::Target {
- self.as_bytes()
+ self.as_ref()
}
}
@@ -325,7 +420,7 @@ where
#[inline]
fn index(&self, index: Idx) -> &Self::Output {
- &self.as_bytes()[index]
+ &self.as_ref()[index]
}
}
@@ -355,6 +450,21 @@ macro_rules! c_str {
#[cfg(test)]
mod tests {
use super::*;
+ use alloc::format;
+
+ const ALL_ASCII_CHARS: &'static str =
+ "\\x01\\x02\\x03\\x04\\x05\\x06\\x07\\x08\\x09\\x0a\\x0b\\x0c\\x0d\\x0e\\x0f\
+ \\x10\\x11\\x12\\x13\\x14\\x15\\x16\\x17\\x18\\x19\\x1a\\x1b\\x1c\\x1d\\x1e\\x1f \
+ !\"#$%&'()*+,-./0123456789:;<=>?@\
+ ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\\x7f\
+ \\x80\\x81\\x82\\x83\\x84\\x85\\x86\\x87\\x88\\x89\\x8a\\x8b\\x8c\\x8d\\x8e\\x8f\
+ \\x90\\x91\\x92\\x93\\x94\\x95\\x96\\x97\\x98\\x99\\x9a\\x9b\\x9c\\x9d\\x9e\\x9f\
+ \\xa0\\xa1\\xa2\\xa3\\xa4\\xa5\\xa6\\xa7\\xa8\\xa9\\xaa\\xab\\xac\\xad\\xae\\xaf\
+ \\xb0\\xb1\\xb2\\xb3\\xb4\\xb5\\xb6\\xb7\\xb8\\xb9\\xba\\xbb\\xbc\\xbd\\xbe\\xbf\
+ \\xc0\\xc1\\xc2\\xc3\\xc4\\xc5\\xc6\\xc7\\xc8\\xc9\\xca\\xcb\\xcc\\xcd\\xce\\xcf\
+ \\xd0\\xd1\\xd2\\xd3\\xd4\\xd5\\xd6\\xd7\\xd8\\xd9\\xda\\xdb\\xdc\\xdd\\xde\\xdf\
+ \\xe0\\xe1\\xe2\\xe3\\xe4\\xe5\\xe6\\xe7\\xe8\\xe9\\xea\\xeb\\xec\\xed\\xee\\xef\
+ \\xf0\\xf1\\xf2\\xf3\\xf4\\xf5\\xf6\\xf7\\xf8\\xf9\\xfa\\xfb\\xfc\\xfd\\xfe\\xff";
#[test]
fn test_cstr_to_str() {
@@ -379,6 +489,69 @@ mod tests {
let unchecked_str = unsafe { checked_cstr.as_str_unchecked() };
assert_eq!(unchecked_str, "🐧");
}
+
+ #[test]
+ fn test_cstr_display() {
+ let hello_world = CStr::from_bytes_with_nul(b"hello, world!\0").unwrap();
+ assert_eq!(format!("{}", hello_world), "hello, world!");
+ let non_printables = CStr::from_bytes_with_nul(b"\x01\x09\x0a\0").unwrap();
+ assert_eq!(format!("{}", non_printables), "\\x01\\x09\\x0a");
+ let non_ascii = CStr::from_bytes_with_nul(b"d\xe9j\xe0 vu\0").unwrap();
+ assert_eq!(format!("{}", non_ascii), "d\\xe9j\\xe0 vu");
+ let good_bytes = CStr::from_bytes_with_nul(b"\xf0\x9f\xa6\x80\0").unwrap();
+ assert_eq!(format!("{}", good_bytes), "\\xf0\\x9f\\xa6\\x80");
+ }
+
+ #[test]
+ fn test_cstr_display_all_bytes() {
+ let mut bytes: [u8; 256] = [0; 256];
+ // fill `bytes` with [1..=255] + [0]
+ for i in u8::MIN..=u8::MAX {
+ bytes[i as usize] = i.wrapping_add(1);
+ }
+ let cstr = CStr::from_bytes_with_nul(&bytes).unwrap();
+ assert_eq!(format!("{}", cstr), ALL_ASCII_CHARS);
+ }
+
+ #[test]
+ fn test_cstr_debug() {
+ let hello_world = CStr::from_bytes_with_nul(b"hello, world!\0").unwrap();
+ assert_eq!(format!("{:?}", hello_world), "\"hello, world!\"");
+ let non_printables = CStr::from_bytes_with_nul(b"\x01\x09\x0a\0").unwrap();
+ assert_eq!(format!("{:?}", non_printables), "\"\\x01\\x09\\x0a\"");
+ let non_ascii = CStr::from_bytes_with_nul(b"d\xe9j\xe0 vu\0").unwrap();
+ assert_eq!(format!("{:?}", non_ascii), "\"d\\xe9j\\xe0 vu\"");
+ let good_bytes = CStr::from_bytes_with_nul(b"\xf0\x9f\xa6\x80\0").unwrap();
+ assert_eq!(format!("{:?}", good_bytes), "\"\\xf0\\x9f\\xa6\\x80\"");
+ }
+
+ #[test]
+ fn test_bstr_display() {
+ let hello_world = BStr::from_bytes(b"hello, world!");
+ assert_eq!(format!("{}", hello_world), "hello, world!");
+ let escapes = BStr::from_bytes(b"_\t_\n_\r_\\_\'_\"_");
+ assert_eq!(format!("{}", escapes), "_\\t_\\n_\\r_\\_'_\"_");
+ let others = BStr::from_bytes(b"\x01");
+ assert_eq!(format!("{}", others), "\\x01");
+ let non_ascii = BStr::from_bytes(b"d\xe9j\xe0 vu");
+ assert_eq!(format!("{}", non_ascii), "d\\xe9j\\xe0 vu");
+ let good_bytes = BStr::from_bytes(b"\xf0\x9f\xa6\x80");
+ assert_eq!(format!("{}", good_bytes), "\\xf0\\x9f\\xa6\\x80");
+ }
+
+ #[test]
+ fn test_bstr_debug() {
+ let hello_world = BStr::from_bytes(b"hello, world!");
+ assert_eq!(format!("{:?}", hello_world), "\"hello, world!\"");
+ let escapes = BStr::from_bytes(b"_\t_\n_\r_\\_\'_\"_");
+ assert_eq!(format!("{:?}", escapes), "\"_\\t_\\n_\\r_\\\\_'_\\\"_\"");
+ let others = BStr::from_bytes(b"\x01");
+ assert_eq!(format!("{:?}", others), "\"\\x01\"");
+ let non_ascii = BStr::from_bytes(b"d\xe9j\xe0 vu");
+ assert_eq!(format!("{:?}", non_ascii), "\"d\\xe9j\\xe0 vu\"");
+ let good_bytes = BStr::from_bytes(b"\xf0\x9f\xa6\x80");
+ assert_eq!(format!("{:?}", good_bytes), "\"\\xf0\\x9f\\xa6\\x80\"");
+ }
}
/// Allows formatting of [`fmt::Arguments`] into a raw buffer.
@@ -447,7 +620,7 @@ impl RawFormatter {
self.pos as _
}
- /// Return the number of bytes written to the formatter.
+ /// Returns the number of bytes written to the formatter.
pub(crate) fn bytes_written(&self) -> usize {
self.pos - self.beg
}
@@ -529,7 +702,7 @@ impl fmt::Write for Formatter {
/// # Examples
///
/// ```
-/// use kernel::str::CString;
+/// use kernel::{str::CString, fmt};
///
/// let s = CString::try_from_fmt(fmt!("{}{}{}", "abc", 10, 20)).unwrap();
/// assert_eq!(s.as_bytes_with_nul(), "abc1020\0".as_bytes());
@@ -606,6 +779,12 @@ impl<'a> TryFrom<&'a CStr> for CString {
}
}
+impl fmt::Debug for CString {
+ fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+ fmt::Debug::fmt(&**self, f)
+ }
+}
+
/// A convenience alias for [`core::format_args`].
#[macro_export]
macro_rules! fmt {
diff --git a/rust/kernel/sync.rs b/rust/kernel/sync.rs
index d219ee518eff..c983f63fd56e 100644
--- a/rust/kernel/sync.rs
+++ b/rust/kernel/sync.rs
@@ -13,8 +13,9 @@ pub mod lock;
mod locked_by;
pub use arc::{Arc, ArcBorrow, UniqueArc};
-pub use condvar::CondVar;
-pub use lock::{mutex::Mutex, spinlock::SpinLock};
+pub use condvar::{new_condvar, CondVar, CondVarTimeoutResult};
+pub use lock::mutex::{new_mutex, Mutex};
+pub use lock::spinlock::{new_spinlock, SpinLock};
pub use locked_by::LockedBy;
/// Represents a lockdep class. It's a wrapper around C's `lock_class_key`.
diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs
index 172f563976a9..7d4c4bf58388 100644
--- a/rust/kernel/sync/arc.rs
+++ b/rust/kernel/sync/arc.rs
@@ -24,7 +24,7 @@ use crate::{
};
use alloc::boxed::Box;
use core::{
- alloc::AllocError,
+ alloc::{AllocError, Layout},
fmt,
marker::{PhantomData, Unsize},
mem::{ManuallyDrop, MaybeUninit},
@@ -56,7 +56,7 @@ mod std_vendor;
/// b: u32,
/// }
///
-/// // Create a ref-counted instance of `Example`.
+/// // Create a refcounted instance of `Example`.
/// let obj = Arc::try_new(Example { a: 10, b: 20 })?;
///
/// // Get a new pointer to `obj` and increment the refcount.
@@ -73,6 +73,7 @@ mod std_vendor;
/// assert_eq!(cloned.b, 20);
///
/// // The refcount drops to zero when `cloned` goes out of scope, and the memory is freed.
+/// # Ok::<(), Error>(())
/// ```
///
/// Using `Arc<T>` as the type of `self`:
@@ -98,6 +99,7 @@ mod std_vendor;
/// let obj = Arc::try_new(Example { a: 10, b: 20 })?;
/// obj.use_reference();
/// obj.take_over();
+/// # Ok::<(), Error>(())
/// ```
///
/// Coercion from `Arc<Example>` to `Arc<dyn MyTrait>`:
@@ -121,6 +123,7 @@ mod std_vendor;
///
/// // `coerced` has type `Arc<dyn MyTrait>`.
/// let coerced: Arc<dyn MyTrait> = obj;
+/// # Ok::<(), Error>(())
/// ```
pub struct Arc<T: ?Sized> {
ptr: NonNull<ArcInner<T>>,
@@ -212,6 +215,46 @@ impl<T: ?Sized> Arc<T> {
}
}
+ /// Convert the [`Arc`] into a raw pointer.
+ ///
+ /// The raw pointer has ownership of the refcount that this Arc object owned.
+ pub fn into_raw(self) -> *const T {
+ let ptr = self.ptr.as_ptr();
+ core::mem::forget(self);
+ // SAFETY: The pointer is valid.
+ unsafe { core::ptr::addr_of!((*ptr).data) }
+ }
+
+ /// Recreates an [`Arc`] instance previously deconstructed via [`Arc::into_raw`].
+ ///
+ /// # Safety
+ ///
+ /// `ptr` must have been returned by a previous call to [`Arc::into_raw`]. Additionally, it
+ /// must not be called more than once for each previous call to [`Arc::into_raw`].
+ pub unsafe fn from_raw(ptr: *const T) -> Self {
+ let refcount_layout = Layout::new::<bindings::refcount_t>();
+ // SAFETY: The caller guarantees that the pointer is valid.
+ let val_layout = Layout::for_value(unsafe { &*ptr });
+ // SAFETY: We're computing the layout of a real struct that existed when compiling this
+ // binary, so its layout is not so large that it can trigger arithmetic overflow.
+ let val_offset = unsafe { refcount_layout.extend(val_layout).unwrap_unchecked().1 };
+
+ // Pointer casts leave the metadata unchanged. This is okay because the metadata of `T` and
+ // `ArcInner<T>` is the same since `ArcInner` is a struct with `T` as its last field.
+ //
+ // This is documented at:
+ // <https://doc.rust-lang.org/std/ptr/trait.Pointee.html>.
+ let ptr = ptr as *const ArcInner<T>;
+
+ // SAFETY: The pointer is in-bounds of an allocation both before and after offsetting the
+ // pointer, since it originates from a previous call to `Arc::into_raw` and is still valid.
+ let ptr = unsafe { ptr.byte_sub(val_offset) };
+
+ // SAFETY: By the safety requirements we know that `ptr` came from `Arc::into_raw`, so the
+ // reference count held then will be owned by the new `Arc` object.
+ unsafe { Self::from_inner(NonNull::new_unchecked(ptr.cast_mut())) }
+ }
+
/// Returns an [`ArcBorrow`] from the given [`Arc`].
///
/// This is useful when the argument of a function call is an [`ArcBorrow`] (e.g., in a method
@@ -299,7 +342,7 @@ impl<T: ?Sized> Drop for Arc<T> {
// The count reached zero, we must free the memory.
//
// SAFETY: The pointer was initialised from the result of `Box::leak`.
- unsafe { Box::from_raw(self.ptr.as_ptr()) };
+ unsafe { drop(Box::from_raw(self.ptr.as_ptr())) };
}
}
}
@@ -320,12 +363,12 @@ impl<T: ?Sized> From<Pin<UniqueArc<T>>> for Arc<T> {
/// A borrowed reference to an [`Arc`] instance.
///
/// For cases when one doesn't ever need to increment the refcount on the allocation, it is simpler
-/// to use just `&T`, which we can trivially get from an `Arc<T>` instance.
+/// to use just `&T`, which we can trivially get from an [`Arc<T>`] instance.
///
/// However, when one may need to increment the refcount, it is preferable to use an `ArcBorrow<T>`
/// over `&Arc<T>` because the latter results in a double-indirection: a pointer (shared reference)
-/// to a pointer (`Arc<T>`) to the object (`T`). An [`ArcBorrow`] eliminates this double
-/// indirection while still allowing one to increment the refcount and getting an `Arc<T>` when/if
+/// to a pointer ([`Arc<T>`]) to the object (`T`). An [`ArcBorrow`] eliminates this double
+/// indirection while still allowing one to increment the refcount and getting an [`Arc<T>`] when/if
/// needed.
///
/// # Invariants
@@ -336,7 +379,7 @@ impl<T: ?Sized> From<Pin<UniqueArc<T>>> for Arc<T> {
/// # Example
///
/// ```
-/// use crate::sync::{Arc, ArcBorrow};
+/// use kernel::sync::{Arc, ArcBorrow};
///
/// struct Example;
///
@@ -349,12 +392,13 @@ impl<T: ?Sized> From<Pin<UniqueArc<T>>> for Arc<T> {
///
/// // Assert that both `obj` and `cloned` point to the same underlying object.
/// assert!(core::ptr::eq(&*obj, &*cloned));
+/// # Ok::<(), Error>(())
/// ```
///
/// Using `ArcBorrow<T>` as the type of `self`:
///
/// ```
-/// use crate::sync::{Arc, ArcBorrow};
+/// use kernel::sync::{Arc, ArcBorrow};
///
/// struct Example {
/// a: u32,
@@ -369,6 +413,7 @@ impl<T: ?Sized> From<Pin<UniqueArc<T>>> for Arc<T> {
///
/// let obj = Arc::try_new(Example { a: 10, b: 20 })?;
/// obj.as_arc_borrow().use_reference();
+/// # Ok::<(), Error>(())
/// ```
pub struct ArcBorrow<'a, T: ?Sized + 'a> {
inner: NonNull<ArcInner<T>>,
@@ -463,7 +508,7 @@ impl<T: ?Sized> Deref for ArcBorrow<'_, T> {
/// # test().unwrap();
/// ```
///
-/// In the following example we first allocate memory for a ref-counted `Example` but we don't
+/// In the following example we first allocate memory for a refcounted `Example` but we don't
/// initialise it on allocation. We do initialise it later with a call to [`UniqueArc::write`],
/// followed by a conversion to `Arc<Example>`. This is particularly useful when allocation happens
/// in one context (e.g., sleepable) and initialisation in another (e.g., atomic):
@@ -513,7 +558,7 @@ impl<T> UniqueArc<T> {
/// Tries to allocate a new [`UniqueArc`] instance.
pub fn try_new(value: T) -> Result<Self, AllocError> {
Ok(Self {
- // INVARIANT: The newly-created object has a ref-count of 1.
+ // INVARIANT: The newly-created object has a refcount of 1.
inner: Arc::try_new(value)?,
})
}
@@ -527,7 +572,7 @@ impl<T> UniqueArc<T> {
data <- init::uninit::<T, AllocError>(),
}? AllocError))?;
Ok(UniqueArc {
- // INVARIANT: The newly-created object has a ref-count of 1.
+ // INVARIANT: The newly-created object has a refcount of 1.
// SAFETY: The pointer from the `Box` is valid.
inner: unsafe { Arc::from_inner(Box::leak(inner).into()) },
})
diff --git a/rust/kernel/sync/condvar.rs b/rust/kernel/sync/condvar.rs
index ed353399c4e5..0c3671caffeb 100644
--- a/rust/kernel/sync/condvar.rs
+++ b/rust/kernel/sync/condvar.rs
@@ -6,8 +6,18 @@
//! variable.
use super::{lock::Backend, lock::Guard, LockClassKey};
-use crate::{bindings, init::PinInit, pin_init, str::CStr, types::Opaque};
+use crate::{
+ bindings,
+ init::PinInit,
+ pin_init,
+ str::CStr,
+ task::{MAX_SCHEDULE_TIMEOUT, TASK_INTERRUPTIBLE, TASK_NORMAL, TASK_UNINTERRUPTIBLE},
+ time::Jiffies,
+ types::Opaque,
+};
+use core::ffi::{c_int, c_long};
use core::marker::PhantomPinned;
+use core::ptr;
use macros::pin_data;
/// Creates a [`CondVar`] initialiser with the given name and a newly-created lock class.
@@ -17,6 +27,7 @@ macro_rules! new_condvar {
$crate::sync::CondVar::new($crate::optional_name!($($name)?), $crate::static_lock_class!())
};
}
+pub use new_condvar;
/// A conditional variable.
///
@@ -34,8 +45,7 @@ macro_rules! new_condvar {
/// The following is an example of using a condvar with a mutex:
///
/// ```
-/// use kernel::sync::{CondVar, Mutex};
-/// use kernel::{new_condvar, new_mutex};
+/// use kernel::sync::{new_condvar, new_mutex, CondVar, Mutex};
///
/// #[pin_data]
/// pub struct Example {
@@ -50,7 +60,7 @@ macro_rules! new_condvar {
/// fn wait_for_value(e: &Example, v: u32) {
/// let mut guard = e.value.lock();
/// while *guard != v {
-/// e.value_changed.wait_uninterruptible(&mut guard);
+/// e.value_changed.wait(&mut guard);
/// }
/// }
///
@@ -69,14 +79,16 @@ macro_rules! new_condvar {
/// }
/// ```
///
-/// [`struct wait_queue_head`]: ../../../include/linux/wait.h
+/// [`struct wait_queue_head`]: srctree/include/linux/wait.h
#[pin_data]
pub struct CondVar {
#[pin]
- pub(crate) wait_list: Opaque<bindings::wait_queue_head>,
+ pub(crate) wait_queue_head: Opaque<bindings::wait_queue_head>,
/// A condvar needs to be pinned because it contains a [`struct list_head`] that is
/// self-referential, so it cannot be safely moved once it is initialised.
+ ///
+ /// [`struct list_head`]: srctree/include/linux/types.h
#[pin]
_pin: PhantomPinned,
}
@@ -91,77 +103,114 @@ unsafe impl Sync for CondVar {}
impl CondVar {
/// Constructs a new condvar initialiser.
- #[allow(clippy::new_ret_no_self)]
pub fn new(name: &'static CStr, key: &'static LockClassKey) -> impl PinInit<Self> {
pin_init!(Self {
_pin: PhantomPinned,
// SAFETY: `slot` is valid while the closure is called and both `name` and `key` have
// static lifetimes so they live indefinitely.
- wait_list <- Opaque::ffi_init(|slot| unsafe {
+ wait_queue_head <- Opaque::ffi_init(|slot| unsafe {
bindings::__init_waitqueue_head(slot, name.as_char_ptr(), key.as_ptr())
}),
})
}
- fn wait_internal<T: ?Sized, B: Backend>(&self, wait_state: u32, guard: &mut Guard<'_, T, B>) {
+ fn wait_internal<T: ?Sized, B: Backend>(
+ &self,
+ wait_state: c_int,
+ guard: &mut Guard<'_, T, B>,
+ timeout_in_jiffies: c_long,
+ ) -> c_long {
let wait = Opaque::<bindings::wait_queue_entry>::uninit();
// SAFETY: `wait` points to valid memory.
unsafe { bindings::init_wait(wait.get()) };
- // SAFETY: Both `wait` and `wait_list` point to valid memory.
+ // SAFETY: Both `wait` and `wait_queue_head` point to valid memory.
unsafe {
- bindings::prepare_to_wait_exclusive(self.wait_list.get(), wait.get(), wait_state as _)
+ bindings::prepare_to_wait_exclusive(self.wait_queue_head.get(), wait.get(), wait_state)
};
- // SAFETY: No arguments, switches to another thread.
- guard.do_unlocked(|| unsafe { bindings::schedule() });
+ // SAFETY: Switches to another thread. The timeout can be any number.
+ let ret = guard.do_unlocked(|| unsafe { bindings::schedule_timeout(timeout_in_jiffies) });
+
+ // SAFETY: Both `wait` and `wait_queue_head` point to valid memory.
+ unsafe { bindings::finish_wait(self.wait_queue_head.get(), wait.get()) };
- // SAFETY: Both `wait` and `wait_list` point to valid memory.
- unsafe { bindings::finish_wait(self.wait_list.get(), wait.get()) };
+ ret
}
- /// Releases the lock and waits for a notification in interruptible mode.
+ /// Releases the lock and waits for a notification in uninterruptible mode.
///
/// Atomically releases the given lock (whose ownership is proven by the guard) and puts the
/// thread to sleep, reacquiring the lock on wake up. It wakes up when notified by
- /// [`CondVar::notify_one`] or [`CondVar::notify_all`], or when the thread receives a signal.
- /// It may also wake up spuriously.
+ /// [`CondVar::notify_one`] or [`CondVar::notify_all`]. Note that it may also wake up
+ /// spuriously.
+ pub fn wait<T: ?Sized, B: Backend>(&self, guard: &mut Guard<'_, T, B>) {
+ self.wait_internal(TASK_UNINTERRUPTIBLE, guard, MAX_SCHEDULE_TIMEOUT);
+ }
+
+ /// Releases the lock and waits for a notification in interruptible mode.
+ ///
+ /// Similar to [`CondVar::wait`], except that the wait is interruptible. That is, the thread may
+ /// wake up due to signals. It may also wake up spuriously.
///
/// Returns whether there is a signal pending.
- #[must_use = "wait returns if a signal is pending, so the caller must check the return value"]
- pub fn wait<T: ?Sized, B: Backend>(&self, guard: &mut Guard<'_, T, B>) -> bool {
- self.wait_internal(bindings::TASK_INTERRUPTIBLE, guard);
+ #[must_use = "wait_interruptible returns if a signal is pending, so the caller must check the return value"]
+ pub fn wait_interruptible<T: ?Sized, B: Backend>(&self, guard: &mut Guard<'_, T, B>) -> bool {
+ self.wait_internal(TASK_INTERRUPTIBLE, guard, MAX_SCHEDULE_TIMEOUT);
crate::current!().signal_pending()
}
- /// Releases the lock and waits for a notification in uninterruptible mode.
+ /// Releases the lock and waits for a notification in interruptible mode.
///
- /// Similar to [`CondVar::wait`], except that the wait is not interruptible. That is, the
- /// thread won't wake up due to signals. It may, however, wake up supirously.
- pub fn wait_uninterruptible<T: ?Sized, B: Backend>(&self, guard: &mut Guard<'_, T, B>) {
- self.wait_internal(bindings::TASK_UNINTERRUPTIBLE, guard)
+ /// Atomically releases the given lock (whose ownership is proven by the guard) and puts the
+ /// thread to sleep. It wakes up when notified by [`CondVar::notify_one`] or
+ /// [`CondVar::notify_all`], or when a timeout occurs, or when the thread receives a signal.
+ #[must_use = "wait_interruptible_timeout returns if a signal is pending, so the caller must check the return value"]
+ pub fn wait_interruptible_timeout<T: ?Sized, B: Backend>(
+ &self,
+ guard: &mut Guard<'_, T, B>,
+ jiffies: Jiffies,
+ ) -> CondVarTimeoutResult {
+ let jiffies = jiffies.try_into().unwrap_or(MAX_SCHEDULE_TIMEOUT);
+ let res = self.wait_internal(TASK_INTERRUPTIBLE, guard, jiffies);
+
+ match (res as Jiffies, crate::current!().signal_pending()) {
+ (jiffies, true) => CondVarTimeoutResult::Signal { jiffies },
+ (0, false) => CondVarTimeoutResult::Timeout,
+ (jiffies, false) => CondVarTimeoutResult::Woken { jiffies },
+ }
}
- /// Calls the kernel function to notify the appropriate number of threads with the given flags.
- fn notify(&self, count: i32, flags: u32) {
- // SAFETY: `wait_list` points to valid memory.
+ /// Calls the kernel function to notify the appropriate number of threads.
+ fn notify(&self, count: c_int) {
+ // SAFETY: `wait_queue_head` points to valid memory.
unsafe {
bindings::__wake_up(
- self.wait_list.get(),
- bindings::TASK_NORMAL,
+ self.wait_queue_head.get(),
+ TASK_NORMAL,
count,
- flags as _,
+ ptr::null_mut(),
)
};
}
+ /// Calls the kernel function to notify one thread synchronously.
+ ///
+ /// This method behaves like `notify_one`, except that it hints to the scheduler that the
+ /// current thread is about to go to sleep, so it should schedule the target thread on the same
+ /// CPU.
+ pub fn notify_sync(&self) {
+ // SAFETY: `wait_queue_head` points to valid memory.
+ unsafe { bindings::__wake_up_sync(self.wait_queue_head.get(), TASK_NORMAL) };
+ }
+
/// Wakes a single waiter up, if any.
///
/// This is not 'sticky' in the sense that if no thread is waiting, the notification is lost
/// completely (as opposed to automatically waking up the next waiter).
pub fn notify_one(&self) {
- self.notify(1, 0);
+ self.notify(1);
}
/// Wakes all waiters up, if any.
@@ -169,6 +218,22 @@ impl CondVar {
/// This is not 'sticky' in the sense that if no thread is waiting, the notification is lost
/// completely (as opposed to automatically waking up the next waiter).
pub fn notify_all(&self) {
- self.notify(0, 0);
+ self.notify(0);
}
}
+
+/// The return type of `wait_timeout`.
+pub enum CondVarTimeoutResult {
+ /// The timeout was reached.
+ Timeout,
+ /// Somebody woke us up.
+ Woken {
+ /// Remaining sleep duration.
+ jiffies: Jiffies,
+ },
+ /// A signal occurred.
+ Signal {
+ /// Remaining sleep duration.
+ jiffies: Jiffies,
+ },
+}
diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs
index a2216325632d..5b5c8efe427a 100644
--- a/rust/kernel/sync/lock.rs
+++ b/rust/kernel/sync/lock.rs
@@ -21,14 +21,21 @@ pub mod spinlock;
/// # Safety
///
/// - Implementers must ensure that only one thread/CPU may access the protected data once the lock
-/// is owned, that is, between calls to `lock` and `unlock`.
-/// - Implementers must also ensure that `relock` uses the same locking method as the original
-/// lock operation.
+/// is owned, that is, between calls to [`lock`] and [`unlock`].
+/// - Implementers must also ensure that [`relock`] uses the same locking method as the original
+/// lock operation.
+///
+/// [`lock`]: Backend::lock
+/// [`unlock`]: Backend::unlock
+/// [`relock`]: Backend::relock
pub unsafe trait Backend {
/// The state required by the lock.
type State;
- /// The state required to be kept between lock and unlock.
+ /// The state required to be kept between [`lock`] and [`unlock`].
+ ///
+ /// [`lock`]: Backend::lock
+ /// [`unlock`]: Backend::unlock
type GuardState;
/// Initialises the lock.
@@ -72,8 +79,8 @@ pub unsafe trait Backend {
/// A mutual exclusion primitive.
///
-/// Exposes one of the kernel locking primitives. Which one is exposed depends on the lock backend
-/// specified as the generic parameter `B`.
+/// Exposes one of the kernel locking primitives. Which one is exposed depends on the lock
+/// [`Backend`] specified as the generic parameter `B`.
#[pin_data]
pub struct Lock<T: ?Sized, B: Backend> {
/// The kernel lock object.
@@ -99,7 +106,6 @@ unsafe impl<T: ?Sized + Send, B: Backend> Sync for Lock<T, B> {}
impl<T, B: Backend> Lock<T, B> {
/// Constructs a new lock initialiser.
- #[allow(clippy::new_ret_no_self)]
pub fn new(t: T, name: &'static CStr, key: &'static LockClassKey) -> impl PinInit<Self> {
pin_init!(Self {
data: UnsafeCell::new(t),
@@ -126,7 +132,7 @@ impl<T: ?Sized, B: Backend> Lock<T, B> {
/// A lock guard.
///
-/// Allows mutual exclusion primitives that implement the `Backend` trait to automatically unlock
+/// Allows mutual exclusion primitives that implement the [`Backend`] trait to automatically unlock
/// when a guard goes out of scope. It also provides a safe and convenient way to access the data
/// protected by the lock.
#[must_use = "the lock unlocks immediately when the guard is unused"]
@@ -140,7 +146,7 @@ pub struct Guard<'a, T: ?Sized, B: Backend> {
unsafe impl<T: Sync + ?Sized, B: Backend> Sync for Guard<'_, T, B> {}
impl<T: ?Sized, B: Backend> Guard<'_, T, B> {
- pub(crate) fn do_unlocked(&mut self, cb: impl FnOnce()) {
+ pub(crate) fn do_unlocked<U>(&mut self, cb: impl FnOnce() -> U) -> U {
// SAFETY: The caller owns the lock, so it is safe to unlock it.
unsafe { B::unlock(self.lock.state.get(), &self.state) };
@@ -148,7 +154,7 @@ impl<T: ?Sized, B: Backend> Guard<'_, T, B> {
let _relock =
ScopeGuard::new(|| unsafe { B::relock(self.lock.state.get(), &mut self.state) });
- cb();
+ cb()
}
}
diff --git a/rust/kernel/sync/lock/mutex.rs b/rust/kernel/sync/lock/mutex.rs
index 923472f04af4..ef4c4634d294 100644
--- a/rust/kernel/sync/lock/mutex.rs
+++ b/rust/kernel/sync/lock/mutex.rs
@@ -17,6 +17,7 @@ macro_rules! new_mutex {
$inner, $crate::optional_name!($($name)?), $crate::static_lock_class!())
};
}
+pub use new_mutex;
/// A mutual exclusion primitive.
///
@@ -35,7 +36,7 @@ macro_rules! new_mutex {
/// contains an inner struct (`Inner`) that is protected by a mutex.
///
/// ```
-/// use kernel::{init::InPlaceInit, init::PinInit, new_mutex, pin_init, sync::Mutex};
+/// use kernel::sync::{new_mutex, Mutex};
///
/// struct Inner {
/// a: u32,
@@ -63,6 +64,7 @@ macro_rules! new_mutex {
/// assert_eq!(e.c, 10);
/// assert_eq!(e.d.lock().a, 20);
/// assert_eq!(e.d.lock().b, 30);
+/// # Ok::<(), Error>(())
/// ```
///
/// The following example shows how to use interior mutability to modify the contents of a struct
@@ -83,7 +85,7 @@ macro_rules! new_mutex {
/// }
/// ```
///
-/// [`struct mutex`]: ../../../../include/linux/mutex.h
+/// [`struct mutex`]: srctree/include/linux/mutex.h
pub type Mutex<T> = super::Lock<T, MutexBackend>;
/// A kernel `struct mutex` lock backend.
diff --git a/rust/kernel/sync/lock/spinlock.rs b/rust/kernel/sync/lock/spinlock.rs
index 979b56464a4e..0b22c635634f 100644
--- a/rust/kernel/sync/lock/spinlock.rs
+++ b/rust/kernel/sync/lock/spinlock.rs
@@ -17,6 +17,7 @@ macro_rules! new_spinlock {
$inner, $crate::optional_name!($($name)?), $crate::static_lock_class!())
};
}
+pub use new_spinlock;
/// A spinlock.
///
@@ -33,7 +34,7 @@ macro_rules! new_spinlock {
/// contains an inner struct (`Inner`) that is protected by a spinlock.
///
/// ```
-/// use kernel::{init::InPlaceInit, init::PinInit, new_spinlock, pin_init, sync::SpinLock};
+/// use kernel::sync::{new_spinlock, SpinLock};
///
/// struct Inner {
/// a: u32,
@@ -61,6 +62,7 @@ macro_rules! new_spinlock {
/// assert_eq!(e.c, 10);
/// assert_eq!(e.d.lock().a, 20);
/// assert_eq!(e.d.lock().b, 30);
+/// # Ok::<(), Error>(())
/// ```
///
/// The following example shows how to use interior mutability to modify the contents of a struct
@@ -81,7 +83,7 @@ macro_rules! new_spinlock {
/// }
/// ```
///
-/// [`spinlock_t`]: ../../../../include/linux/spinlock.h
+/// [`spinlock_t`]: srctree/include/linux/spinlock.h
pub type SpinLock<T> = super::Lock<T, SpinLockBackend>;
/// A kernel `spinlock_t` lock backend.
@@ -111,7 +113,7 @@ unsafe impl super::Backend for SpinLockBackend {
unsafe fn unlock(ptr: *mut Self::State, _guard_state: &Self::GuardState) {
// SAFETY: The safety requirements of this function ensure that `ptr` is valid and that the
- // caller is the owner of the mutex.
+ // caller is the owner of the spinlock.
unsafe { bindings::spin_unlock(ptr) }
}
}
diff --git a/rust/kernel/sync/locked_by.rs b/rust/kernel/sync/locked_by.rs
index b17ee5cd98f3..babc731bd5f6 100644
--- a/rust/kernel/sync/locked_by.rs
+++ b/rust/kernel/sync/locked_by.rs
@@ -9,14 +9,17 @@ use core::{cell::UnsafeCell, mem::size_of, ptr};
/// Allows access to some data to be serialised by a lock that does not wrap it.
///
/// In most cases, data protected by a lock is wrapped by the appropriate lock type, e.g.,
-/// [`super::Mutex`] or [`super::SpinLock`]. [`LockedBy`] is meant for cases when this is not
-/// possible. For example, if a container has a lock and some data in the contained elements needs
+/// [`Mutex`] or [`SpinLock`]. [`LockedBy`] is meant for cases when this is not possible.
+/// For example, if a container has a lock and some data in the contained elements needs
/// to be protected by the same lock.
///
/// [`LockedBy`] wraps the data in lieu of another locking primitive, and only allows access to it
/// when the caller shows evidence that the 'external' lock is locked. It panics if the evidence
/// refers to the wrong instance of the lock.
///
+/// [`Mutex`]: super::Mutex
+/// [`SpinLock`]: super::SpinLock
+///
/// # Examples
///
/// The following is an example for illustrative purposes: `InnerDirectory::bytes_used` is an
diff --git a/rust/kernel/task.rs b/rust/kernel/task.rs
index 7eda15e5f1b3..ca6e7e31d71c 100644
--- a/rust/kernel/task.rs
+++ b/rust/kernel/task.rs
@@ -2,10 +2,26 @@
//! Tasks (threads and processes).
//!
-//! C header: [`include/linux/sched.h`](../../../../include/linux/sched.h).
+//! C header: [`include/linux/sched.h`](srctree/include/linux/sched.h).
use crate::{bindings, types::Opaque};
-use core::{marker::PhantomData, ops::Deref, ptr};
+use core::{
+ ffi::{c_int, c_long, c_uint},
+ marker::PhantomData,
+ ops::Deref,
+ ptr,
+};
+
+/// A sentinel value used for infinite timeouts.
+pub const MAX_SCHEDULE_TIMEOUT: c_long = c_long::MAX;
+
+/// Bitmask for tasks that are sleeping in an interruptible state.
+pub const TASK_INTERRUPTIBLE: c_int = bindings::TASK_INTERRUPTIBLE as c_int;
+/// Bitmask for tasks that are sleeping in an uninterruptible state.
+pub const TASK_UNINTERRUPTIBLE: c_int = bindings::TASK_UNINTERRUPTIBLE as c_int;
+/// Convenience constant for waking up tasks regardless of whether they are in interruptible or
+/// uninterruptible sleep.
+pub const TASK_NORMAL: c_uint = bindings::TASK_NORMAL as c_uint;
/// Returns the currently running task.
#[macro_export]
@@ -23,7 +39,7 @@ macro_rules! current {
///
/// All instances are valid tasks created by the C portion of the kernel.
///
-/// Instances of this type are always ref-counted, that is, a call to `get_task_struct` ensures
+/// Instances of this type are always refcounted, that is, a call to `get_task_struct` ensures
/// that the allocation remains valid at least until the matching call to `put_task_struct`.
///
/// # Examples
@@ -82,7 +98,7 @@ impl Task {
/// Returns a task reference for the currently executing task/thread.
///
/// The recommended way to get the current task/thread is to use the
- /// [`current`](crate::current) macro because it is safe.
+ /// [`current`] macro because it is safe.
///
/// # Safety
///
@@ -116,7 +132,7 @@ impl Task {
/// Returns the group leader of the given task.
pub fn group_leader(&self) -> &Task {
// SAFETY: By the type invariant, we know that `self.0` is a valid task. Valid tasks always
- // have a valid group_leader.
+ // have a valid `group_leader`.
let ptr = unsafe { *ptr::addr_of!((*self.0.get()).group_leader) };
// SAFETY: The lifetime of the returned task reference is tied to the lifetime of `self`,
@@ -147,7 +163,7 @@ impl Task {
}
}
-// SAFETY: The type invariants guarantee that `Task` is always ref-counted.
+// SAFETY: The type invariants guarantee that `Task` is always refcounted.
unsafe impl crate::types::AlwaysRefCounted for Task {
fn inc_ref(&self) {
// SAFETY: The existence of a shared reference means that the refcount is nonzero.
diff --git a/rust/kernel/time.rs b/rust/kernel/time.rs
new file mode 100644
index 000000000000..25a896eed468
--- /dev/null
+++ b/rust/kernel/time.rs
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Time related primitives.
+//!
+//! This module contains the kernel APIs related to time and timers that
+//! have been ported or wrapped for usage by Rust code in the kernel.
+
+/// The time unit of Linux kernel. One jiffy equals (1/HZ) second.
+pub type Jiffies = core::ffi::c_ulong;
+
+/// The millisecond time unit.
+pub type Msecs = core::ffi::c_uint;
+
+/// Converts milliseconds to jiffies.
+#[inline]
+pub fn msecs_to_jiffies(msecs: Msecs) -> Jiffies {
+ // SAFETY: The `__msecs_to_jiffies` function is always safe to call no
+ // matter what the argument is.
+ unsafe { bindings::__msecs_to_jiffies(msecs) }
+}
diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
index d479f8da8f38..aa77bad9bce4 100644
--- a/rust/kernel/types.rs
+++ b/rust/kernel/types.rs
@@ -6,7 +6,7 @@ use crate::init::{self, PinInit};
use alloc::boxed::Box;
use core::{
cell::UnsafeCell,
- marker::PhantomData,
+ marker::{PhantomData, PhantomPinned},
mem::MaybeUninit,
ops::{Deref, DerefMut},
ptr::NonNull,
@@ -46,6 +46,25 @@ pub trait ForeignOwnable: Sized {
/// Additionally, all instances (if any) of values returned by [`ForeignOwnable::borrow`] for
/// this object must have been dropped.
unsafe fn from_foreign(ptr: *const core::ffi::c_void) -> Self;
+
+ /// Tries to convert a foreign-owned object back to a Rust-owned one.
+ ///
+ /// A convenience wrapper over [`ForeignOwnable::from_foreign`] that returns [`None`] if `ptr`
+ /// is null.
+ ///
+ /// # Safety
+ ///
+ /// `ptr` must either be null or satisfy the safety requirements for
+ /// [`ForeignOwnable::from_foreign`].
+ unsafe fn try_from_foreign(ptr: *const core::ffi::c_void) -> Option<Self> {
+ if ptr.is_null() {
+ None
+ } else {
+ // SAFETY: Since `ptr` is not null here, then `ptr` satisfies the safety requirements
+ // of `from_foreign` given the safety requirements of this function.
+ unsafe { Some(Self::from_foreign(ptr)) }
+ }
+ }
}
impl<T: 'static> ForeignOwnable for Box<T> {
@@ -90,8 +109,9 @@ impl ForeignOwnable for () {
///
/// In the example below, we have multiple exit paths and we want to log regardless of which one is
/// taken:
+///
/// ```
-/// # use kernel::ScopeGuard;
+/// # use kernel::types::ScopeGuard;
/// fn example1(arg: bool) {
/// let _log = ScopeGuard::new(|| pr_info!("example1 completed\n"));
///
@@ -108,8 +128,9 @@ impl ForeignOwnable for () {
///
/// In the example below, we want to log the same message on all early exits but a different one on
/// the main exit path:
+///
/// ```
-/// # use kernel::ScopeGuard;
+/// # use kernel::types::ScopeGuard;
/// fn example2(arg: bool) {
/// let log = ScopeGuard::new(|| pr_info!("example2 returned early\n"));
///
@@ -129,8 +150,9 @@ impl ForeignOwnable for () {
///
/// In the example below, we need a mutable object (the vector) to be accessible within the log
/// function, so we wrap it in the [`ScopeGuard`]:
+///
/// ```
-/// # use kernel::ScopeGuard;
+/// # use kernel::types::ScopeGuard;
/// fn example3(arg: bool) -> Result {
/// let mut vec =
/// ScopeGuard::new_with_data(Vec::new(), |v| pr_info!("vec had {} elements\n", v.len()));
@@ -206,17 +228,26 @@ impl<T, F: FnOnce(T)> Drop for ScopeGuard<T, F> {
///
/// This is meant to be used with FFI objects that are never interpreted by Rust code.
#[repr(transparent)]
-pub struct Opaque<T>(MaybeUninit<UnsafeCell<T>>);
+pub struct Opaque<T> {
+ value: UnsafeCell<MaybeUninit<T>>,
+ _pin: PhantomPinned,
+}
impl<T> Opaque<T> {
/// Creates a new opaque value.
pub const fn new(value: T) -> Self {
- Self(MaybeUninit::new(UnsafeCell::new(value)))
+ Self {
+ value: UnsafeCell::new(MaybeUninit::new(value)),
+ _pin: PhantomPinned,
+ }
}
/// Creates an uninitialised value.
pub const fn uninit() -> Self {
- Self(MaybeUninit::uninit())
+ Self {
+ value: UnsafeCell::new(MaybeUninit::uninit()),
+ _pin: PhantomPinned,
+ }
}
/// Creates a pin-initializer from the given initializer closure.
@@ -240,7 +271,7 @@ impl<T> Opaque<T> {
/// Returns a raw pointer to the opaque data.
pub fn get(&self) -> *mut T {
- UnsafeCell::raw_get(self.0.as_ptr())
+ UnsafeCell::get(&self.value).cast::<T>()
}
/// Gets the value behind `this`.
@@ -248,7 +279,7 @@ impl<T> Opaque<T> {
/// This function is useful to get access to the value without creating intermediate
/// references.
pub const fn raw_get(this: *const Self) -> *mut T {
- UnsafeCell::raw_get(this.cast::<UnsafeCell<T>>())
+ UnsafeCell::raw_get(this.cast::<UnsafeCell<MaybeUninit<T>>>()).cast::<T>()
}
}
diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs
new file mode 100644
index 000000000000..480cb292e7c2
--- /dev/null
+++ b/rust/kernel/workqueue.rs
@@ -0,0 +1,681 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Work queues.
+//!
+//! This file has two components: The raw work item API, and the safe work item API.
+//!
+//! One pattern that is used in both APIs is the `ID` const generic, which exists to allow a single
+//! type to define multiple `work_struct` fields. This is done by choosing an id for each field,
+//! and using that id to specify which field you wish to use. (The actual value doesn't matter, as
+//! long as you use different values for different fields of the same struct.) Since these IDs are
+//! generic, they are used only at compile-time, so they shouldn't exist in the final binary.
+//!
+//! # The raw API
+//!
+//! The raw API consists of the [`RawWorkItem`] trait, where the work item needs to provide an
+//! arbitrary function that knows how to enqueue the work item. It should usually not be used
+//! directly, but if you want to, you can use it without using the pieces from the safe API.
+//!
+//! # The safe API
+//!
+//! The safe API is used via the [`Work`] struct and [`WorkItem`] traits. Furthermore, it also
+//! includes a trait called [`WorkItemPointer`], which is usually not used directly by the user.
+//!
+//! * The [`Work`] struct is the Rust wrapper for the C `work_struct` type.
+//! * The [`WorkItem`] trait is implemented for structs that can be enqueued to a workqueue.
+//! * The [`WorkItemPointer`] trait is implemented for the pointer type that points at a something
+//! that implements [`WorkItem`].
+//!
+//! ## Example
+//!
+//! This example defines a struct that holds an integer and can be scheduled on the workqueue. When
+//! the struct is executed, it will print the integer. Since there is only one `work_struct` field,
+//! we do not need to specify ids for the fields.
+//!
+//! ```
+//! use kernel::prelude::*;
+//! use kernel::sync::Arc;
+//! use kernel::workqueue::{self, impl_has_work, new_work, Work, WorkItem};
+//!
+//! #[pin_data]
+//! struct MyStruct {
+//! value: i32,
+//! #[pin]
+//! work: Work<MyStruct>,
+//! }
+//!
+//! impl_has_work! {
+//! impl HasWork<Self> for MyStruct { self.work }
+//! }
+//!
+//! impl MyStruct {
+//! fn new(value: i32) -> Result<Arc<Self>> {
+//! Arc::pin_init(pin_init!(MyStruct {
+//! value,
+//! work <- new_work!("MyStruct::work"),
+//! }))
+//! }
+//! }
+//!
+//! impl WorkItem for MyStruct {
+//! type Pointer = Arc<MyStruct>;
+//!
+//! fn run(this: Arc<MyStruct>) {
+//! pr_info!("The value is: {}", this.value);
+//! }
+//! }
+//!
+//! /// This method will enqueue the struct for execution on the system workqueue, where its value
+//! /// will be printed.
+//! fn print_later(val: Arc<MyStruct>) {
+//! let _ = workqueue::system().enqueue(val);
+//! }
+//! ```
+//!
+//! The following example shows how multiple `work_struct` fields can be used:
+//!
+//! ```
+//! use kernel::prelude::*;
+//! use kernel::sync::Arc;
+//! use kernel::workqueue::{self, impl_has_work, new_work, Work, WorkItem};
+//!
+//! #[pin_data]
+//! struct MyStruct {
+//! value_1: i32,
+//! value_2: i32,
+//! #[pin]
+//! work_1: Work<MyStruct, 1>,
+//! #[pin]
+//! work_2: Work<MyStruct, 2>,
+//! }
+//!
+//! impl_has_work! {
+//! impl HasWork<Self, 1> for MyStruct { self.work_1 }
+//! impl HasWork<Self, 2> for MyStruct { self.work_2 }
+//! }
+//!
+//! impl MyStruct {
+//! fn new(value_1: i32, value_2: i32) -> Result<Arc<Self>> {
+//! Arc::pin_init(pin_init!(MyStruct {
+//! value_1,
+//! value_2,
+//! work_1 <- new_work!("MyStruct::work_1"),
+//! work_2 <- new_work!("MyStruct::work_2"),
+//! }))
+//! }
+//! }
+//!
+//! impl WorkItem<1> for MyStruct {
+//! type Pointer = Arc<MyStruct>;
+//!
+//! fn run(this: Arc<MyStruct>) {
+//! pr_info!("The value is: {}", this.value_1);
+//! }
+//! }
+//!
+//! impl WorkItem<2> for MyStruct {
+//! type Pointer = Arc<MyStruct>;
+//!
+//! fn run(this: Arc<MyStruct>) {
+//! pr_info!("The second value is: {}", this.value_2);
+//! }
+//! }
+//!
+//! fn print_1_later(val: Arc<MyStruct>) {
+//! let _ = workqueue::system().enqueue::<Arc<MyStruct>, 1>(val);
+//! }
+//!
+//! fn print_2_later(val: Arc<MyStruct>) {
+//! let _ = workqueue::system().enqueue::<Arc<MyStruct>, 2>(val);
+//! }
+//! ```
+//!
+//! C header: [`include/linux/workqueue.h`](srctree/include/linux/workqueue.h)
+
+use crate::{bindings, prelude::*, sync::Arc, sync::LockClassKey, types::Opaque};
+use alloc::alloc::AllocError;
+use alloc::boxed::Box;
+use core::marker::PhantomData;
+use core::pin::Pin;
+
+/// Creates a [`Work`] initialiser with the given name and a newly-created lock class.
+#[macro_export]
+macro_rules! new_work {
+ ($($name:literal)?) => {
+ $crate::workqueue::Work::new($crate::optional_name!($($name)?), $crate::static_lock_class!())
+ };
+}
+pub use new_work;
+
+/// A kernel work queue.
+///
+/// Wraps the kernel's C `struct workqueue_struct`.
+///
+/// It allows work items to be queued to run on thread pools managed by the kernel. Several are
+/// always available, for example, `system`, `system_highpri`, `system_long`, etc.
+#[repr(transparent)]
+pub struct Queue(Opaque<bindings::workqueue_struct>);
+
+// SAFETY: Accesses to workqueues used by [`Queue`] are thread-safe.
+unsafe impl Send for Queue {}
+// SAFETY: Accesses to workqueues used by [`Queue`] are thread-safe.
+unsafe impl Sync for Queue {}
+
+impl Queue {
+ /// Use the provided `struct workqueue_struct` with Rust.
+ ///
+ /// # Safety
+ ///
+ /// The caller must ensure that the provided raw pointer is not dangling, that it points at a
+ /// valid workqueue, and that it remains valid until the end of `'a`.
+ pub unsafe fn from_raw<'a>(ptr: *const bindings::workqueue_struct) -> &'a Queue {
+ // SAFETY: The `Queue` type is `#[repr(transparent)]`, so the pointer cast is valid. The
+ // caller promises that the pointer is not dangling.
+ unsafe { &*(ptr as *const Queue) }
+ }
+
+ /// Enqueues a work item.
+ ///
+ /// This may fail if the work item is already enqueued in a workqueue.
+ ///
+ /// The work item will be submitted using `WORK_CPU_UNBOUND`.
+ pub fn enqueue<W, const ID: u64>(&self, w: W) -> W::EnqueueOutput
+ where
+ W: RawWorkItem<ID> + Send + 'static,
+ {
+ let queue_ptr = self.0.get();
+
+ // SAFETY: We only return `false` if the `work_struct` is already in a workqueue. The other
+ // `__enqueue` requirements are not relevant since `W` is `Send` and static.
+ //
+ // The call to `bindings::queue_work_on` will dereference the provided raw pointer, which
+ // is ok because `__enqueue` guarantees that the pointer is valid for the duration of this
+ // closure.
+ //
+ // Furthermore, if the C workqueue code accesses the pointer after this call to
+ // `__enqueue`, then the work item was successfully enqueued, and `bindings::queue_work_on`
+ // will have returned true. In this case, `__enqueue` promises that the raw pointer will
+ // stay valid until we call the function pointer in the `work_struct`, so the access is ok.
+ unsafe {
+ w.__enqueue(move |work_ptr| {
+ bindings::queue_work_on(
+ bindings::wq_misc_consts_WORK_CPU_UNBOUND as _,
+ queue_ptr,
+ work_ptr,
+ )
+ })
+ }
+ }
+
+ /// Tries to spawn the given function or closure as a work item.
+ ///
+ /// This method can fail because it allocates memory to store the work item.
+ pub fn try_spawn<T: 'static + Send + FnOnce()>(&self, func: T) -> Result<(), AllocError> {
+ let init = pin_init!(ClosureWork {
+ work <- new_work!("Queue::try_spawn"),
+ func: Some(func),
+ });
+
+ self.enqueue(Box::pin_init(init).map_err(|_| AllocError)?);
+ Ok(())
+ }
+}
+
+/// A helper type used in [`try_spawn`].
+///
+/// [`try_spawn`]: Queue::try_spawn
+#[pin_data]
+struct ClosureWork<T> {
+ #[pin]
+ work: Work<ClosureWork<T>>,
+ func: Option<T>,
+}
+
+impl<T> ClosureWork<T> {
+ fn project(self: Pin<&mut Self>) -> &mut Option<T> {
+ // SAFETY: The `func` field is not structurally pinned.
+ unsafe { &mut self.get_unchecked_mut().func }
+ }
+}
+
+impl<T: FnOnce()> WorkItem for ClosureWork<T> {
+ type Pointer = Pin<Box<Self>>;
+
+ fn run(mut this: Pin<Box<Self>>) {
+ if let Some(func) = this.as_mut().project().take() {
+ (func)()
+ }
+ }
+}
+
+/// A raw work item.
+///
+/// This is the low-level trait that is designed for being as general as possible.
+///
+/// The `ID` parameter to this trait exists so that a single type can provide multiple
+/// implementations of this trait. For example, if a struct has multiple `work_struct` fields, then
+/// you will implement this trait once for each field, using a different id for each field. The
+/// actual value of the id is not important as long as you use different ids for different fields
+/// of the same struct. (Fields of different structs need not use different ids.)
+///
+/// Note that the id is used only to select the right method to call during compilation. It won't be
+/// part of the final executable.
+///
+/// # Safety
+///
+/// Implementers must ensure that any pointers passed to a `queue_work_on` closure by [`__enqueue`]
+/// remain valid for the duration specified in the guarantees section of the documentation for
+/// [`__enqueue`].
+///
+/// [`__enqueue`]: RawWorkItem::__enqueue
+pub unsafe trait RawWorkItem<const ID: u64> {
+ /// The return type of [`Queue::enqueue`].
+ type EnqueueOutput;
+
+ /// Enqueues this work item on a queue using the provided `queue_work_on` method.
+ ///
+ /// # Guarantees
+ ///
+ /// If this method calls the provided closure, then the raw pointer is guaranteed to point at a
+ /// valid `work_struct` for the duration of the call to the closure. If the closure returns
+ /// true, then it is further guaranteed that the pointer remains valid until someone calls the
+ /// function pointer stored in the `work_struct`.
+ ///
+ /// # Safety
+ ///
+ /// The provided closure may only return `false` if the `work_struct` is already in a workqueue.
+ ///
+ /// If the work item type is annotated with any lifetimes, then you must not call the function
+ /// pointer after any such lifetime expires. (Never calling the function pointer is okay.)
+ ///
+ /// If the work item type is not [`Send`], then the function pointer must be called on the same
+ /// thread as the call to `__enqueue`.
+ unsafe fn __enqueue<F>(self, queue_work_on: F) -> Self::EnqueueOutput
+ where
+ F: FnOnce(*mut bindings::work_struct) -> bool;
+}
+
+/// Defines the method that should be called directly when a work item is executed.
+///
+/// This trait is implemented by `Pin<Box<T>>` and [`Arc<T>`], and is mainly intended to be
+/// implemented for smart pointer types. For your own structs, you would implement [`WorkItem`]
+/// instead. The [`run`] method on this trait will usually just perform the appropriate
+/// `container_of` translation and then call into the [`run`][WorkItem::run] method from the
+/// [`WorkItem`] trait.
+///
+/// This trait is used when the `work_struct` field is defined using the [`Work`] helper.
+///
+/// # Safety
+///
+/// Implementers must ensure that [`__enqueue`] uses a `work_struct` initialized with the [`run`]
+/// method of this trait as the function pointer.
+///
+/// [`__enqueue`]: RawWorkItem::__enqueue
+/// [`run`]: WorkItemPointer::run
+pub unsafe trait WorkItemPointer<const ID: u64>: RawWorkItem<ID> {
+ /// Run this work item.
+ ///
+ /// # Safety
+ ///
+ /// The provided `work_struct` pointer must originate from a previous call to [`__enqueue`]
+ /// where the `queue_work_on` closure returned true, and the pointer must still be valid.
+ ///
+ /// [`__enqueue`]: RawWorkItem::__enqueue
+ unsafe extern "C" fn run(ptr: *mut bindings::work_struct);
+}
+
+/// Defines the method that should be called when this work item is executed.
+///
+/// This trait is used when the `work_struct` field is defined using the [`Work`] helper.
+pub trait WorkItem<const ID: u64 = 0> {
+ /// The pointer type that this struct is wrapped in. This will typically be `Arc<Self>` or
+ /// `Pin<Box<Self>>`.
+ type Pointer: WorkItemPointer<ID>;
+
+ /// The method that should be called when this work item is executed.
+ fn run(this: Self::Pointer);
+}
+
+/// Links for a work item.
+///
+/// This struct contains a function pointer to the [`run`] function from the [`WorkItemPointer`]
+/// trait, and defines the linked list pointers necessary to enqueue a work item in a workqueue.
+///
+/// Wraps the kernel's C `struct work_struct`.
+///
+/// This is a helper type used to associate a `work_struct` with the [`WorkItem`] that uses it.
+///
+/// [`run`]: WorkItemPointer::run
+#[repr(transparent)]
+pub struct Work<T: ?Sized, const ID: u64 = 0> {
+ work: Opaque<bindings::work_struct>,
+ _inner: PhantomData<T>,
+}
+
+// SAFETY: Kernel work items are usable from any thread.
+//
+// We do not need to constrain `T` since the work item does not actually contain a `T`.
+unsafe impl<T: ?Sized, const ID: u64> Send for Work<T, ID> {}
+// SAFETY: Kernel work items are usable from any thread.
+//
+// We do not need to constrain `T` since the work item does not actually contain a `T`.
+unsafe impl<T: ?Sized, const ID: u64> Sync for Work<T, ID> {}
+
+impl<T: ?Sized, const ID: u64> Work<T, ID> {
+ /// Creates a new instance of [`Work`].
+ #[inline]
+ #[allow(clippy::new_ret_no_self)]
+ pub fn new(name: &'static CStr, key: &'static LockClassKey) -> impl PinInit<Self>
+ where
+ T: WorkItem<ID>,
+ {
+ // SAFETY: The `WorkItemPointer` implementation promises that `run` can be used as the work
+ // item function.
+ unsafe {
+ kernel::init::pin_init_from_closure(move |slot| {
+ let slot = Self::raw_get(slot);
+ bindings::init_work_with_key(
+ slot,
+ Some(T::Pointer::run),
+ false,
+ name.as_char_ptr(),
+ key.as_ptr(),
+ );
+ Ok(())
+ })
+ }
+ }
+
+ /// Get a pointer to the inner `work_struct`.
+ ///
+ /// # Safety
+ ///
+ /// The provided pointer must not be dangling and must be properly aligned. (But the memory
+ /// need not be initialized.)
+ #[inline]
+ pub unsafe fn raw_get(ptr: *const Self) -> *mut bindings::work_struct {
+ // SAFETY: The caller promises that the pointer is aligned and not dangling.
+ //
+ // A pointer cast would also be ok due to `#[repr(transparent)]`. We use `addr_of!` so that
+ // the compiler does not complain that the `work` field is unused.
+ unsafe { Opaque::raw_get(core::ptr::addr_of!((*ptr).work)) }
+ }
+}
+
+/// Declares that a type has a [`Work<T, ID>`] field.
+///
+/// The intended way of using this trait is via the [`impl_has_work!`] macro. You can use the macro
+/// like this:
+///
+/// ```no_run
+/// use kernel::prelude::*;
+/// use kernel::workqueue::{impl_has_work, Work};
+///
+/// struct MyWorkItem {
+/// work_field: Work<MyWorkItem, 1>,
+/// }
+///
+/// impl_has_work! {
+/// impl HasWork<MyWorkItem, 1> for MyWorkItem { self.work_field }
+/// }
+/// ```
+///
+/// Note that since the [`Work`] type is annotated with an id, you can have several `work_struct`
+/// fields by using a different id for each one.
+///
+/// # Safety
+///
+/// The [`OFFSET`] constant must be the offset of a field in `Self` of type [`Work<T, ID>`]. The
+/// methods on this trait must have exactly the behavior that the definitions given below have.
+///
+/// [`impl_has_work!`]: crate::impl_has_work
+/// [`OFFSET`]: HasWork::OFFSET
+pub unsafe trait HasWork<T, const ID: u64 = 0> {
+ /// The offset of the [`Work<T, ID>`] field.
+ const OFFSET: usize;
+
+ /// Returns the offset of the [`Work<T, ID>`] field.
+ ///
+ /// This method exists because the [`OFFSET`] constant cannot be accessed if the type is not
+ /// [`Sized`].
+ ///
+ /// [`OFFSET`]: HasWork::OFFSET
+ #[inline]
+ fn get_work_offset(&self) -> usize {
+ Self::OFFSET
+ }
+
+ /// Returns a pointer to the [`Work<T, ID>`] field.
+ ///
+ /// # Safety
+ ///
+ /// The provided pointer must point at a valid struct of type `Self`.
+ #[inline]
+ unsafe fn raw_get_work(ptr: *mut Self) -> *mut Work<T, ID> {
+ // SAFETY: The caller promises that the pointer is valid.
+ unsafe { (ptr as *mut u8).add(Self::OFFSET) as *mut Work<T, ID> }
+ }
+
+ /// Returns a pointer to the struct containing the [`Work<T, ID>`] field.
+ ///
+ /// # Safety
+ ///
+ /// The pointer must point at a [`Work<T, ID>`] field in a struct of type `Self`.
+ #[inline]
+ unsafe fn work_container_of(ptr: *mut Work<T, ID>) -> *mut Self
+ where
+ Self: Sized,
+ {
+ // SAFETY: The caller promises that the pointer points at a field of the right type in the
+ // right kind of struct.
+ unsafe { (ptr as *mut u8).sub(Self::OFFSET) as *mut Self }
+ }
+}
+
+/// Used to safely implement the [`HasWork<T, ID>`] trait.
+///
+/// # Examples
+///
+/// ```
+/// use kernel::sync::Arc;
+/// use kernel::workqueue::{self, impl_has_work, Work};
+///
+/// struct MyStruct {
+/// work_field: Work<MyStruct, 17>,
+/// }
+///
+/// impl_has_work! {
+/// impl HasWork<MyStruct, 17> for MyStruct { self.work_field }
+/// }
+/// ```
+#[macro_export]
+macro_rules! impl_has_work {
+ ($(impl$(<$($implarg:ident),*>)?
+ HasWork<$work_type:ty $(, $id:tt)?>
+ for $self:ident $(<$($selfarg:ident),*>)?
+ { self.$field:ident }
+ )*) => {$(
+ // SAFETY: The implementation of `raw_get_work` only compiles if the field has the right
+ // type.
+ unsafe impl$(<$($implarg),*>)? $crate::workqueue::HasWork<$work_type $(, $id)?> for $self $(<$($selfarg),*>)? {
+ const OFFSET: usize = ::core::mem::offset_of!(Self, $field) as usize;
+
+ #[inline]
+ unsafe fn raw_get_work(ptr: *mut Self) -> *mut $crate::workqueue::Work<$work_type $(, $id)?> {
+ // SAFETY: The caller promises that the pointer is not dangling.
+ unsafe {
+ ::core::ptr::addr_of_mut!((*ptr).$field)
+ }
+ }
+ }
+ )*};
+}
+pub use impl_has_work;
+
+impl_has_work! {
+ impl<T> HasWork<Self> for ClosureWork<T> { self.work }
+}
+
+unsafe impl<T, const ID: u64> WorkItemPointer<ID> for Arc<T>
+where
+ T: WorkItem<ID, Pointer = Self>,
+ T: HasWork<T, ID>,
+{
+ unsafe extern "C" fn run(ptr: *mut bindings::work_struct) {
+ // SAFETY: The `__enqueue` method always uses a `work_struct` stored in a `Work<T, ID>`.
+ let ptr = ptr as *mut Work<T, ID>;
+ // SAFETY: This computes the pointer that `__enqueue` got from `Arc::into_raw`.
+ let ptr = unsafe { T::work_container_of(ptr) };
+ // SAFETY: This pointer comes from `Arc::into_raw` and we've been given back ownership.
+ let arc = unsafe { Arc::from_raw(ptr) };
+
+ T::run(arc)
+ }
+}
+
+unsafe impl<T, const ID: u64> RawWorkItem<ID> for Arc<T>
+where
+ T: WorkItem<ID, Pointer = Self>,
+ T: HasWork<T, ID>,
+{
+ type EnqueueOutput = Result<(), Self>;
+
+ unsafe fn __enqueue<F>(self, queue_work_on: F) -> Self::EnqueueOutput
+ where
+ F: FnOnce(*mut bindings::work_struct) -> bool,
+ {
+ // Casting between const and mut is not a problem as long as the pointer is a raw pointer.
+ let ptr = Arc::into_raw(self).cast_mut();
+
+ // SAFETY: Pointers into an `Arc` point at a valid value.
+ let work_ptr = unsafe { T::raw_get_work(ptr) };
+ // SAFETY: `raw_get_work` returns a pointer to a valid value.
+ let work_ptr = unsafe { Work::raw_get(work_ptr) };
+
+ if queue_work_on(work_ptr) {
+ Ok(())
+ } else {
+ // SAFETY: The work queue has not taken ownership of the pointer.
+ Err(unsafe { Arc::from_raw(ptr) })
+ }
+ }
+}
+
+unsafe impl<T, const ID: u64> WorkItemPointer<ID> for Pin<Box<T>>
+where
+ T: WorkItem<ID, Pointer = Self>,
+ T: HasWork<T, ID>,
+{
+ unsafe extern "C" fn run(ptr: *mut bindings::work_struct) {
+ // SAFETY: The `__enqueue` method always uses a `work_struct` stored in a `Work<T, ID>`.
+ let ptr = ptr as *mut Work<T, ID>;
+ // SAFETY: This computes the pointer that `__enqueue` got from `Arc::into_raw`.
+ let ptr = unsafe { T::work_container_of(ptr) };
+ // SAFETY: This pointer comes from `Arc::into_raw` and we've been given back ownership.
+ let boxed = unsafe { Box::from_raw(ptr) };
+ // SAFETY: The box was already pinned when it was enqueued.
+ let pinned = unsafe { Pin::new_unchecked(boxed) };
+
+ T::run(pinned)
+ }
+}
+
+unsafe impl<T, const ID: u64> RawWorkItem<ID> for Pin<Box<T>>
+where
+ T: WorkItem<ID, Pointer = Self>,
+ T: HasWork<T, ID>,
+{
+ type EnqueueOutput = ();
+
+ unsafe fn __enqueue<F>(self, queue_work_on: F) -> Self::EnqueueOutput
+ where
+ F: FnOnce(*mut bindings::work_struct) -> bool,
+ {
+ // SAFETY: We're not going to move `self` or any of its fields, so its okay to temporarily
+ // remove the `Pin` wrapper.
+ let boxed = unsafe { Pin::into_inner_unchecked(self) };
+ let ptr = Box::into_raw(boxed);
+
+ // SAFETY: Pointers into a `Box` point at a valid value.
+ let work_ptr = unsafe { T::raw_get_work(ptr) };
+ // SAFETY: `raw_get_work` returns a pointer to a valid value.
+ let work_ptr = unsafe { Work::raw_get(work_ptr) };
+
+ if !queue_work_on(work_ptr) {
+ // SAFETY: This method requires exclusive ownership of the box, so it cannot be in a
+ // workqueue.
+ unsafe { ::core::hint::unreachable_unchecked() }
+ }
+ }
+}
+
+/// Returns the system work queue (`system_wq`).
+///
+/// It is the one used by `schedule[_delayed]_work[_on]()`. Multi-CPU multi-threaded. There are
+/// users which expect relatively short queue flush time.
+///
+/// Callers shouldn't queue work items which can run for too long.
+pub fn system() -> &'static Queue {
+ // SAFETY: `system_wq` is a C global, always available.
+ unsafe { Queue::from_raw(bindings::system_wq) }
+}
+
+/// Returns the system high-priority work queue (`system_highpri_wq`).
+///
+/// It is similar to the one returned by [`system`] but for work items which require higher
+/// scheduling priority.
+pub fn system_highpri() -> &'static Queue {
+ // SAFETY: `system_highpri_wq` is a C global, always available.
+ unsafe { Queue::from_raw(bindings::system_highpri_wq) }
+}
+
+/// Returns the system work queue for potentially long-running work items (`system_long_wq`).
+///
+/// It is similar to the one returned by [`system`] but may host long running work items. Queue
+/// flushing might take relatively long.
+pub fn system_long() -> &'static Queue {
+ // SAFETY: `system_long_wq` is a C global, always available.
+ unsafe { Queue::from_raw(bindings::system_long_wq) }
+}
+
+/// Returns the system unbound work queue (`system_unbound_wq`).
+///
+/// Workers are not bound to any specific CPU, not concurrency managed, and all queued work items
+/// are executed immediately as long as `max_active` limit is not reached and resources are
+/// available.
+pub fn system_unbound() -> &'static Queue {
+ // SAFETY: `system_unbound_wq` is a C global, always available.
+ unsafe { Queue::from_raw(bindings::system_unbound_wq) }
+}
+
+/// Returns the system freezable work queue (`system_freezable_wq`).
+///
+/// It is equivalent to the one returned by [`system`] except that it's freezable.
+///
+/// A freezable workqueue participates in the freeze phase of the system suspend operations. Work
+/// items on the workqueue are drained and no new work item starts execution until thawed.
+pub fn system_freezable() -> &'static Queue {
+ // SAFETY: `system_freezable_wq` is a C global, always available.
+ unsafe { Queue::from_raw(bindings::system_freezable_wq) }
+}
+
+/// Returns the system power-efficient work queue (`system_power_efficient_wq`).
+///
+/// It is inclined towards saving power and is converted to "unbound" variants if the
+/// `workqueue.power_efficient` kernel parameter is specified; otherwise, it is similar to the one
+/// returned by [`system`].
+pub fn system_power_efficient() -> &'static Queue {
+ // SAFETY: `system_power_efficient_wq` is a C global, always available.
+ unsafe { Queue::from_raw(bindings::system_power_efficient_wq) }
+}
+
+/// Returns the system freezable power-efficient work queue (`system_freezable_power_efficient_wq`).
+///
+/// It is similar to the one returned by [`system_power_efficient`] except that is freezable.
+///
+/// A freezable workqueue participates in the freeze phase of the system suspend operations. Work
+/// items on the workqueue are drained and no new work item starts execution until thawed.
+pub fn system_freezable_power_efficient() -> &'static Queue {
+ // SAFETY: `system_freezable_power_efficient_wq` is a C global, always available.
+ unsafe { Queue::from_raw(bindings::system_freezable_power_efficient_wq) }
+}