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rust: driver: remove duplicate ID table

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Previously, `IdArray` contains both device ID table and info table so we
keep a separate copy for MODULE_DEVICE_TABLE for hotplug (which needs to be
just the device ID table). With the info being changed to be carried via
pointers, `IdArray` is now layout compatible with raw ID table and hence
there is no longer a need to keep the distinction.

Deduplicate the code, and remove the redundant copy for hotplug purpose by
just giving the `IdArray` instance a proper symbol name.

While at it, also update the macro to use `::core::line!()` instead of just
`line!()`.

Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://patch.msgid.link/20260629-id_info-v2-10-56fccbe9c5ef@garyguo.net
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
This commit is contained in:
Gary Guo
2026-06-29 13:39:44 +01:00
committed by Danilo Krummrich
parent 2c5d17cdc4
commit 17fcdecb14
1 changed files with 28 additions and 50 deletions
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78
rust/kernel/device_id.rs
View File

@@ -86,29 +86,24 @@ unsafe fn info_unchecked_opt<U>(&self) -> Option<&'static U> {
}
}
/// A zero-terminated device id array.
/// A zero-terminated device id array, followed by context data.
#[repr(C)]
pub struct RawIdArray<T: RawDeviceId, const N: usize> {
pub struct IdArray<T: RawDeviceId, U: 'static, const N: usize> {
// This is `MaybeUninit<T::RawType>` so any bytes inside it can carry provenance in CTFE.
// If this were `T::RawType`, integer fields would not be able to contain pointers.
ids: [MaybeUninit<T::RawType>; N],
sentinel: MaybeUninit<T::RawType>,
}
impl<T: RawDeviceId, const N: usize> RawIdArray<T, N> {
#[doc(hidden)]
pub const fn size(&self) -> usize {
core::mem::size_of::<Self>()
}
}
/// A zero-terminated device id array, followed by context data.
#[repr(C)]
pub struct IdArray<T: RawDeviceId, U: 'static, const N: usize> {
raw_ids: RawIdArray<T, N>,
phantom: PhantomData<&'static U>,
}
// SAFETY: device ID is plain data plus a `&'static U` and can thus be sent between threads safely
// if `&U` can.
unsafe impl<T: RawDeviceId, U: Sync + 'static, const N: usize> Send for IdArray<T, U, N> {}
// SAFETY: device ID is plain data plus a `&'static U` and can thus be shared between threads safely
// if `&U` can.
unsafe impl<T: RawDeviceId, U: Sync + 'static, const N: usize> Sync for IdArray<T, U, N> {}
impl<T: RawDeviceId + RawDeviceIdIndex, U: 'static, const N: usize> IdArray<T, U, N> {
/// Creates a new instance of the array.
///
@@ -137,22 +132,13 @@ impl<T: RawDeviceId + RawDeviceIdIndex, U: 'static, const N: usize> IdArray<T, U
core::mem::forget(ids);
Self {
raw_ids: RawIdArray {
ids: raw_ids,
sentinel: MaybeUninit::zeroed(),
},
ids: raw_ids,
sentinel: MaybeUninit::zeroed(),
phantom: PhantomData,
}
}
}
impl<T: RawDeviceId, U: 'static, const N: usize> IdArray<T, U, N> {
/// Reference to the contained [`RawIdArray`].
pub const fn raw_ids(&self) -> &RawIdArray<T, N> {
&self.raw_ids
}
}
impl<T: RawDeviceId, const N: usize> IdArray<T, (), N> {
/// Creates a new instance of the array without writing index values.
///
@@ -164,10 +150,8 @@ impl<T: RawDeviceId, const N: usize> IdArray<T, (), N> {
core::mem::forget(ids);
Self {
raw_ids: RawIdArray {
ids: raw_ids,
sentinel: MaybeUninit::zeroed(),
},
ids: raw_ids,
sentinel: MaybeUninit::zeroed(),
phantom: PhantomData,
}
}
@@ -200,13 +184,17 @@ macro_rules! module_device_table {
$table_name: ident, $id_info_type: ty,
[$(($id: expr, $info:expr $(,)?)),* $(,)?]
) => {
const $table_name: $crate::device_id::IdArray<
#[export_name =
concat!("__mod_device_table__", ::core::line!(),
"__kmod_", module_path!(),
"__", $table_type,
"__", stringify!($table_name))
]
static $table_name: $crate::device_id::IdArray<
$device_id_ty,
$id_info_type,
{ <[$device_id_ty]>::len(&[$($id,)*]) },
> = $crate::device_id::IdArray::new([$(($id, &$info),)*]);
$crate::module_device_table!($table_type, $table_name);
};
// Case for no ID info.
@@ -215,26 +203,16 @@ macro_rules! module_device_table {
$table_name: ident, @none,
[$($id: expr),* $(,)?]
) => {
const $table_name: $crate::device_id::IdArray<
#[export_name =
concat!("__mod_device_table__", ::core::line!(),
"__kmod_", module_path!(),
"__", $table_type,
"__", stringify!($table_name))
]
static $table_name: $crate::device_id::IdArray<
$device_id_ty,
(),
{ <[$device_id_ty]>::len(&[$($id,)*]) },
> = $crate::device_id::IdArray::new_without_index([$($id),*]);
$crate::module_device_table!($table_type, $table_name);
};
($table_type: literal, $table_name:ident) => {
const _: () = {
#[rustfmt::skip]
#[export_name =
concat!("__mod_device_table__", line!(),
"__kmod_", module_path!(),
"__", $table_type,
"__", stringify!($table_name))
]
static MOD_DEVICE_TABLE: [::core::mem::MaybeUninit<u8>; $table_name.raw_ids().size()] =
unsafe { ::core::mem::transmute_copy($table_name.raw_ids()) };
};
};
}