* [PATCH 1/4] rust: types: add `Opaque::zeroed`
2025-03-12 0:19 [PATCH 0/4] Auxiliary bus Rust abstractions Danilo Krummrich
@ 2025-03-12 0:19 ` Danilo Krummrich
2025-03-12 0:19 ` [PATCH 2/4] rust: auxiliary: add auxiliary driver abstractions Danilo Krummrich
` (3 subsequent siblings)
4 siblings, 0 replies; 7+ messages in thread
From: Danilo Krummrich @ 2025-03-12 0:19 UTC (permalink / raw)
To: gregkh, rafael, ojeda, alex.gaynor, boqun.feng, gary, bjorn3_gh,
benno.lossin, a.hindborg, aliceryhl, tmgross, airlied, acourbot,
jhubbard
Cc: linux-kernel, rust-for-linux, Danilo Krummrich
Analogous to `Opaque::uninit` add `Opaque::zeroed`, which sets the
corresponding memory to zero. In contrast to `Opaque::uninit`, the
corresponding value, depending on its type, may be initialized.
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
rust/kernel/types.rs | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
index 2bbaab83b9d6..f5e7fed903a7 100644
--- a/rust/kernel/types.rs
+++ b/rust/kernel/types.rs
@@ -326,6 +326,14 @@ pub const fn uninit() -> Self {
}
}
+ /// Creates a new zeroed opaque value.
+ pub const fn zeroed() -> Self {
+ Self {
+ value: UnsafeCell::new(MaybeUninit::zeroed()),
+ _pin: PhantomPinned,
+ }
+ }
+
/// Create an opaque pin-initializer from the given pin-initializer.
pub fn pin_init(slot: impl PinInit<T>) -> impl PinInit<Self> {
Self::ffi_init(|ptr: *mut T| {
--
2.48.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 2/4] rust: auxiliary: add auxiliary driver abstractions
2025-03-12 0:19 [PATCH 0/4] Auxiliary bus Rust abstractions Danilo Krummrich
2025-03-12 0:19 ` [PATCH 1/4] rust: types: add `Opaque::zeroed` Danilo Krummrich
@ 2025-03-12 0:19 ` Danilo Krummrich
2025-03-12 0:19 ` [PATCH 3/4] rust: auxiliary: add auxiliary registration Danilo Krummrich
` (2 subsequent siblings)
4 siblings, 0 replies; 7+ messages in thread
From: Danilo Krummrich @ 2025-03-12 0:19 UTC (permalink / raw)
To: gregkh, rafael, ojeda, alex.gaynor, boqun.feng, gary, bjorn3_gh,
benno.lossin, a.hindborg, aliceryhl, tmgross, airlied, acourbot,
jhubbard
Cc: linux-kernel, rust-for-linux, Danilo Krummrich
Implement the basic auxiliary abstractions required to implement a
driver matching an auxiliary device.
The design and implementation is analogous to PCI and platform and is
based on the generic device / driver abstractions.
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
MAINTAINERS | 1 +
rust/bindings/bindings_helper.h | 1 +
rust/helpers/auxiliary.c | 23 ++++
rust/helpers/helpers.c | 1 +
rust/kernel/auxiliary.rs | 233 ++++++++++++++++++++++++++++++++
rust/kernel/lib.rs | 2 +
6 files changed, 261 insertions(+)
create mode 100644 rust/helpers/auxiliary.c
create mode 100644 rust/kernel/auxiliary.rs
diff --git a/MAINTAINERS b/MAINTAINERS
index f5c7022937a7..0a737b28cdfa 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7114,6 +7114,7 @@ F: include/linux/kobj*
F: include/linux/property.h
F: include/linux/sysfs.h
F: lib/kobj*
+F: rust/kernel/auxiliary.rs
F: rust/kernel/device.rs
F: rust/kernel/device_id.rs
F: rust/kernel/devres.rs
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index f46cf3bb7069..83026b6e53b2 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -7,6 +7,7 @@
*/
#include <kunit/test.h>
+#include <linux/auxiliary_bus.h>
#include <linux/blk-mq.h>
#include <linux/blk_types.h>
#include <linux/blkdev.h>
diff --git a/rust/helpers/auxiliary.c b/rust/helpers/auxiliary.c
new file mode 100644
index 000000000000..0db3860d774e
--- /dev/null
+++ b/rust/helpers/auxiliary.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/auxiliary_bus.h>
+
+void rust_helper_auxiliary_set_drvdata(struct auxiliary_device *adev, void *data)
+{
+ auxiliary_set_drvdata(adev, data);
+}
+
+void *rust_helper_auxiliary_get_drvdata(struct auxiliary_device *adev)
+{
+ return auxiliary_get_drvdata(adev);
+}
+
+void rust_helper_auxiliary_device_uninit(struct auxiliary_device *adev)
+{
+ return auxiliary_device_uninit(adev);
+}
+
+void rust_helper_auxiliary_device_delete(struct auxiliary_device *adev)
+{
+ return auxiliary_device_delete(adev);
+}
diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c
index 0640b7e115be..d744af85e3b2 100644
--- a/rust/helpers/helpers.c
+++ b/rust/helpers/helpers.c
@@ -7,6 +7,7 @@
* Sorted alphabetically.
*/
+#include "auxiliary.c"
#include "blk.c"
#include "bug.c"
#include "build_assert.c"
diff --git a/rust/kernel/auxiliary.rs b/rust/kernel/auxiliary.rs
new file mode 100644
index 000000000000..3bdd690990aa
--- /dev/null
+++ b/rust/kernel/auxiliary.rs
@@ -0,0 +1,233 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Abstractions for the auxiliary bus.
+//!
+//! C header: [`include/linux/auxiliary_bus.h`](srctree/include/linux/auxiliary_bus.h)
+
+use crate::{
+ bindings, container_of, device,
+ device_id::RawDeviceId,
+ driver,
+ error::{to_result, Result},
+ prelude::*,
+ str::CStr,
+ types::{ARef, ForeignOwnable, Opaque},
+ ThisModule,
+};
+use core::ptr::addr_of_mut;
+
+/// An adapter for the registration of auxiliary drivers.
+pub struct Adapter<T: Driver>(T);
+
+// SAFETY: A call to `unregister` for a given instance of `RegType` is guaranteed to be valid if
+// a preceding call to `register` has been successful.
+unsafe impl<T: Driver + 'static> driver::RegistrationOps for Adapter<T> {
+ type RegType = bindings::auxiliary_driver;
+
+ unsafe fn register(
+ adrv: &Opaque<Self::RegType>,
+ name: &'static CStr,
+ module: &'static ThisModule,
+ ) -> Result {
+ // SAFETY: It's safe to set the fields of `struct auxiliary_driver` on initialization.
+ unsafe {
+ (*adrv.get()).name = name.as_char_ptr();
+ (*adrv.get()).probe = Some(Self::probe_callback);
+ (*adrv.get()).remove = Some(Self::remove_callback);
+ (*adrv.get()).id_table = T::ID_TABLE.as_ptr();
+ }
+
+ // SAFETY: `adrv` is guaranteed to be a valid `RegType`.
+ to_result(unsafe {
+ bindings::__auxiliary_driver_register(adrv.get(), module.0, name.as_char_ptr())
+ })
+ }
+
+ unsafe fn unregister(adrv: &Opaque<Self::RegType>) {
+ // SAFETY: `adrv` is guaranteed to be a valid `RegType`.
+ unsafe { bindings::auxiliary_driver_unregister(adrv.get()) }
+ }
+}
+
+impl<T: Driver + 'static> Adapter<T> {
+ extern "C" fn probe_callback(
+ adev: *mut bindings::auxiliary_device,
+ id: *const bindings::auxiliary_device_id,
+ ) -> core::ffi::c_int {
+ // SAFETY: The auxiliary bus only ever calls the probe callback with a valid pointer to a
+ // `struct auxiliary_device`.
+ let dev = unsafe { device::Device::get_device(addr_of_mut!((*adev).dev)) };
+ // SAFETY: `dev` is guaranteed to be embedded in a valid `struct auxiliary_device` by the
+ // call above.
+ let mut adev = unsafe { Device::from_dev(dev) };
+
+ // SAFETY: `DeviceId` is a `#[repr(transparent)` wrapper of `struct auxiliary_device_id` and
+ // does not add additional invariants, so it's safe to transmute.
+ let id = unsafe { &*id.cast::<DeviceId>() };
+ let info = T::ID_TABLE.info(id.index());
+
+ match T::probe(&mut adev, info) {
+ Ok(data) => {
+ // Let the `struct auxiliary_device` own a reference of the driver's private data.
+ // SAFETY: By the type invariant `adev.as_raw` returns a valid pointer to a
+ // `struct auxiliary_device`.
+ unsafe { bindings::auxiliary_set_drvdata(adev.as_raw(), data.into_foreign()) };
+ }
+ Err(err) => return Error::to_errno(err),
+ }
+
+ 0
+ }
+
+ extern "C" fn remove_callback(adev: *mut bindings::auxiliary_device) {
+ // SAFETY: The auxiliary bus only ever calls the remove callback with a valid pointer to a
+ // `struct auxiliary_device`.
+ let ptr = unsafe { bindings::auxiliary_get_drvdata(adev) };
+
+ // SAFETY: `remove_callback` is only ever called after a successful call to
+ // `probe_callback`, hence it's guaranteed that `ptr` points to a valid and initialized
+ // `KBox<T>` pointer created through `KBox::into_foreign`.
+ let _ = unsafe { KBox::<T>::from_foreign(ptr) };
+ }
+}
+
+/// Declares a kernel module that exposes a single auxiliary driver.
+#[macro_export]
+macro_rules! module_auxiliary_driver {
+ ($($f:tt)*) => {
+ $crate::module_driver!(<T>, $crate::auxiliary::Adapter<T>, { $($f)* });
+ };
+}
+
+/// Abstraction for `bindings::auxiliary_device_id`.
+#[repr(transparent)]
+#[derive(Clone, Copy)]
+pub struct DeviceId(bindings::auxiliary_device_id);
+
+impl DeviceId {
+ /// Create a new [`DeviceId`] from name.
+ pub const fn new(modname: &'static CStr, name: &'static CStr) -> Self {
+ let name = name.as_bytes_with_nul();
+ let modname = modname.as_bytes_with_nul();
+
+ // TODO: Replace with `bindings::auxiliary_device_id::default()` once stabilized for
+ // `const`.
+ //
+ // SAFETY: FFI type is valid to be zero-initialized.
+ let mut id: bindings::auxiliary_device_id = unsafe { core::mem::zeroed() };
+
+ let mut i = 0;
+ while i < modname.len() {
+ id.name[i] = modname[i];
+ i += 1;
+ }
+
+ // Reuse the space of the NULL terminator.
+ id.name[i - 1] = b'.';
+
+ let mut j = 0;
+ while j < name.len() {
+ id.name[i] = name[j];
+ i += 1;
+ j += 1;
+ }
+
+ Self(id)
+ }
+}
+
+// SAFETY:
+// * `DeviceId` is a `#[repr(transparent)` wrapper of `auxiliary_device_id` and does not add
+// additional invariants, so it's safe to transmute to `RawType`.
+// * `DRIVER_DATA_OFFSET` is the offset to the `driver_data` field.
+unsafe impl RawDeviceId for DeviceId {
+ type RawType = bindings::auxiliary_device_id;
+
+ const DRIVER_DATA_OFFSET: usize =
+ core::mem::offset_of!(bindings::auxiliary_device_id, driver_data);
+
+ fn index(&self) -> usize {
+ self.0.driver_data
+ }
+}
+
+/// IdTable type for auxiliary drivers.
+pub type IdTable<T> = &'static dyn kernel::device_id::IdTable<DeviceId, T>;
+
+/// Create a auxiliary `IdTable` with its alias for modpost.
+#[macro_export]
+macro_rules! auxiliary_device_table {
+ ($table_name:ident, $module_table_name:ident, $id_info_type: ty, $table_data: expr) => {
+ const $table_name: $crate::device_id::IdArray<
+ $crate::auxiliary::DeviceId,
+ $id_info_type,
+ { $table_data.len() },
+ > = $crate::device_id::IdArray::new($table_data);
+
+ $crate::module_device_table!("auxiliary", $module_table_name, $table_name);
+ };
+}
+
+/// The auxiliary driver trait.
+///
+/// Drivers must implement this trait in order to get an auxiliary driver registered.
+pub trait Driver {
+ /// The type holding information about each device id supported by the driver.
+ ///
+ /// TODO: Use associated_type_defaults once stabilized:
+ ///
+ /// type IdInfo: 'static = ();
+ type IdInfo: 'static;
+
+ /// The table of device ids supported by the driver.
+ const ID_TABLE: IdTable<Self::IdInfo>;
+
+ /// Auxiliary driver probe.
+ ///
+ /// Called when a new auxiliary device is added or discovered. Implementers should attempt
+ /// to initialize the device here.
+ fn probe(dev: &mut Device, id_info: &Self::IdInfo) -> Result<Pin<KBox<Self>>>;
+}
+
+/// The auxiliary device representation.
+///
+/// An auxiliary device is based on an always reference counted [`device::Device`] instance. Cloning
+/// an auxiliary device, hence, also increments the base device' reference count.
+///
+/// # Invariants
+///
+/// [`Device`] holds a valid reference of `ARef<device::Device>` whose underlying `struct device` is
+/// a member of a `struct auxiliary_device`.
+#[derive(Clone)]
+pub struct Device(ARef<device::Device>);
+
+impl Device {
+ /// Create an auxiliary [`Device`] instance from an existing [`device::Device`].
+ ///
+ /// # Safety
+ ///
+ /// `dev` must be an `ARef<device::Device>` whose underlying `bindings::device` is a member of
+ /// a `bindings::auxiliary_device`.
+ unsafe fn from_dev(dev: ARef<device::Device>) -> Self {
+ Self(dev)
+ }
+
+ fn as_raw(&self) -> *mut bindings::auxiliary_device {
+ // SAFETY: By the type invariant `self.0.as_raw` is a pointer to the `struct device`
+ // embedded in `struct auxiliary_device`.
+ unsafe { container_of!(self.0.as_raw(), bindings::auxiliary_device, dev).cast_mut() }
+ }
+
+ /// Returns the auxiliary device' id.
+ pub fn id(&self) -> u32 {
+ // SAFETY: By the type invariant `self.as_raw()` is a valid pointer to a
+ // `struct auxiliary_device`.
+ unsafe { (*self.as_raw()).id }
+ }
+}
+
+impl AsRef<device::Device> for Device {
+ fn as_ref(&self) -> &device::Device {
+ &self.0
+ }
+}
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index 398242f92a96..d9a2ca9d1f20 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -36,6 +36,8 @@
pub use ffi;
pub mod alloc;
+#[cfg(CONFIG_AUXILIARY_BUS)]
+pub mod auxiliary;
#[cfg(CONFIG_BLOCK)]
pub mod block;
#[doc(hidden)]
--
2.48.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 3/4] rust: auxiliary: add auxiliary registration
2025-03-12 0:19 [PATCH 0/4] Auxiliary bus Rust abstractions Danilo Krummrich
2025-03-12 0:19 ` [PATCH 1/4] rust: types: add `Opaque::zeroed` Danilo Krummrich
2025-03-12 0:19 ` [PATCH 2/4] rust: auxiliary: add auxiliary driver abstractions Danilo Krummrich
@ 2025-03-12 0:19 ` Danilo Krummrich
2025-03-12 0:19 ` [PATCH 4/4] samples: rust: add Rust auxiliary driver sample Danilo Krummrich
2025-03-12 7:14 ` [PATCH 0/4] Auxiliary bus Rust abstractions Greg KH
4 siblings, 0 replies; 7+ messages in thread
From: Danilo Krummrich @ 2025-03-12 0:19 UTC (permalink / raw)
To: gregkh, rafael, ojeda, alex.gaynor, boqun.feng, gary, bjorn3_gh,
benno.lossin, a.hindborg, aliceryhl, tmgross, airlied, acourbot,
jhubbard
Cc: linux-kernel, rust-for-linux, Danilo Krummrich
Implement the `auxiliary::Registration` type, which provides an API to
create and register new auxiliary devices in the system.
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
rust/kernel/auxiliary.rs | 80 +++++++++++++++++++++++++++++++++++++++-
1 file changed, 79 insertions(+), 1 deletion(-)
diff --git a/rust/kernel/auxiliary.rs b/rust/kernel/auxiliary.rs
index 3bdd690990aa..275dffc64a02 100644
--- a/rust/kernel/auxiliary.rs
+++ b/rust/kernel/auxiliary.rs
@@ -14,7 +14,7 @@
types::{ARef, ForeignOwnable, Opaque},
ThisModule,
};
-use core::ptr::addr_of_mut;
+use core::ptr::{addr_of_mut, NonNull};
/// An adapter for the registration of auxiliary drivers.
pub struct Adapter<T: Driver>(T);
@@ -224,6 +224,16 @@ pub fn id(&self) -> u32 {
// `struct auxiliary_device`.
unsafe { (*self.as_raw()).id }
}
+
+ extern "C" fn release(dev: *mut bindings::device) {
+ // SAFETY: By the type invariant `self.0.as_raw` is a pointer to the `struct device`
+ // embedded in `struct auxiliary_device`.
+ let adev = unsafe { container_of!(dev, bindings::auxiliary_device, dev) }.cast_mut();
+
+ // SAFETY: `adev` points to the memory that has been allocated in `Registration::new`, via
+ // `KBox::new(Opaque::<bindings::auxiliary_device>::zeroed(), GFP_KERNEL)`.
+ let _ = unsafe { KBox::<Opaque<bindings::auxiliary_device>>::from_raw(adev.cast()) };
+ }
}
impl AsRef<device::Device> for Device {
@@ -231,3 +241,71 @@ fn as_ref(&self) -> &device::Device {
&self.0
}
}
+
+/// The registration of an auxiliary device.
+///
+/// This type represents the registration of a [`struct auxiliary_device`]. When an instance of this
+/// type is dropped, its respective auxiliary device will be unregistered from the system.
+///
+/// # Invariants
+///
+/// `self.0` always holds a valid pointer to an initialized and registered
+/// [`struct auxiliary_device`].
+pub struct Registration(NonNull<bindings::auxiliary_device>);
+
+impl Registration {
+ /// Create and register a new auxiliary device.
+ pub fn new(parent: &device::Device, name: &CStr, id: u32, modname: &CStr) -> Result<Self> {
+ let boxed = KBox::new(Opaque::<bindings::auxiliary_device>::zeroed(), GFP_KERNEL)?;
+ let adev = boxed.get();
+
+ // SAFETY: It's safe to set the fields of `struct auxiliary_device` on initialization.
+ unsafe {
+ (*adev).dev.parent = parent.as_raw();
+ (*adev).dev.release = Some(Device::release);
+ (*adev).name = name.as_char_ptr();
+ (*adev).id = id;
+ }
+
+ // SAFETY: `adev` is guaranteed to be a valid pointer to a `struct auxiliary_device`,
+ // which has not been initialized yet.
+ unsafe { bindings::auxiliary_device_init(adev) };
+
+ // Now that `adev` is initialized, leak the `Box`; the corresponding memory will be freed
+ // by `Device::release` when the last reference to the `struct auxiliary_device` is dropped.
+ let _ = KBox::into_raw(boxed);
+
+ // SAFETY:
+ // - `adev` is guaranteed to be a valid pointer to a `struct auxiliary_device`, which has
+ // been initialialized,
+ // - `modname.as_char_ptr()` is a NULL terminated string.
+ let ret = unsafe { bindings::__auxiliary_device_add(adev, modname.as_char_ptr()) };
+ if ret != 0 {
+ // SAFETY: `adev` is guaranteed to be a valid pointer to a `struct auxiliary_device`,
+ // which has been initialialized.
+ unsafe { bindings::auxiliary_device_uninit(adev) };
+
+ return Err(Error::from_errno(ret));
+ }
+
+ // SAFETY: `adev` is guaranteed to be non-null, since the `KBox` was allocated successfully.
+ //
+ // INVARIANT: The device will remain registered until `auxiliary_device_delete()` is called,
+ // which happens in `Self::drop()`.
+ Ok(Self(unsafe { NonNull::new_unchecked(adev) }))
+ }
+}
+
+impl Drop for Registration {
+ fn drop(&mut self) {
+ // SAFETY: By the type invariant of `Self`, `self.0.as_ptr()` is a valid registered
+ // `struct auxiliary_device`.
+ unsafe { bindings::auxiliary_device_delete(self.0.as_ptr()) };
+
+ // This drops the reference we acquired through `auxiliary_device_init()`.
+ //
+ // SAFETY: By the type invariant of `Self`, `self.0.as_ptr()` is a valid registered
+ // `struct auxiliary_device`.
+ unsafe { bindings::auxiliary_device_uninit(self.0.as_ptr()) };
+ }
+}
--
2.48.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* [PATCH 4/4] samples: rust: add Rust auxiliary driver sample
2025-03-12 0:19 [PATCH 0/4] Auxiliary bus Rust abstractions Danilo Krummrich
` (2 preceding siblings ...)
2025-03-12 0:19 ` [PATCH 3/4] rust: auxiliary: add auxiliary registration Danilo Krummrich
@ 2025-03-12 0:19 ` Danilo Krummrich
2025-03-12 7:14 ` [PATCH 0/4] Auxiliary bus Rust abstractions Greg KH
4 siblings, 0 replies; 7+ messages in thread
From: Danilo Krummrich @ 2025-03-12 0:19 UTC (permalink / raw)
To: gregkh, rafael, ojeda, alex.gaynor, boqun.feng, gary, bjorn3_gh,
benno.lossin, a.hindborg, aliceryhl, tmgross, airlied, acourbot,
jhubbard
Cc: linux-kernel, rust-for-linux, Danilo Krummrich
Add a sample Rust auxiliary driver based on a PCI driver for QEMU's
"pci-testdev" device.
The PCI driver only registers an auxiliary device, in order to make the
corresponding auxiliary driver probe.
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
---
MAINTAINERS | 1 +
samples/rust/Kconfig | 10 +++
samples/rust/Makefile | 1 +
samples/rust/rust_driver_auxiliary.rs | 99 +++++++++++++++++++++++++++
4 files changed, 111 insertions(+)
create mode 100644 samples/rust/rust_driver_auxiliary.rs
diff --git a/MAINTAINERS b/MAINTAINERS
index 0a737b28cdfa..6ec20e4f715d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7121,6 +7121,7 @@ F: rust/kernel/devres.rs
F: rust/kernel/driver.rs
F: rust/kernel/faux.rs
F: rust/kernel/platform.rs
+F: samples/rust/rust_driver_auxiliary.rs
F: samples/rust/rust_driver_platform.rs
F: samples/rust/rust_driver_faux.rs
diff --git a/samples/rust/Kconfig b/samples/rust/Kconfig
index 3b6eae84b297..6679d1f1fd48 100644
--- a/samples/rust/Kconfig
+++ b/samples/rust/Kconfig
@@ -71,6 +71,16 @@ config SAMPLE_RUST_DRIVER_FAUX
If unsure, say N.
+config SAMPLE_RUST_DRIVER_AUXILIARY
+ tristate "Auxiliary Driver"
+ help
+ This option builds the Rust auxiliary driver sample.
+
+ To compile this as a module, choose M here:
+ the module will be called rust_driver_auxiliary.
+
+ If unsure, say N.
+
config SAMPLE_RUST_HOSTPROGS
bool "Host programs"
help
diff --git a/samples/rust/Makefile b/samples/rust/Makefile
index 0dbc6d90f1ef..30a8809d0a15 100644
--- a/samples/rust/Makefile
+++ b/samples/rust/Makefile
@@ -7,6 +7,7 @@ obj-$(CONFIG_SAMPLE_RUST_PRINT) += rust_print.o
obj-$(CONFIG_SAMPLE_RUST_DRIVER_PCI) += rust_driver_pci.o
obj-$(CONFIG_SAMPLE_RUST_DRIVER_PLATFORM) += rust_driver_platform.o
obj-$(CONFIG_SAMPLE_RUST_DRIVER_FAUX) += rust_driver_faux.o
+obj-$(CONFIG_SAMPLE_RUST_DRIVER_AUXILIARY) += rust_driver_auxiliary.o
rust_print-y := rust_print_main.o rust_print_events.o
diff --git a/samples/rust/rust_driver_auxiliary.rs b/samples/rust/rust_driver_auxiliary.rs
new file mode 100644
index 000000000000..f9af7c07a2b7
--- /dev/null
+++ b/samples/rust/rust_driver_auxiliary.rs
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0
+
+//! Rust auxiliary driver sample (based on a PCI driver for QEMU's `pci-testdev`).
+//!
+//! To make this driver probe, QEMU must be run with `-device pci-testdev`.
+
+use kernel::{
+ auxiliary, bindings, c_str, driver, error::Error, init, pci, prelude::*, str::CStr,
+ InPlaceModule,
+};
+
+const MODULE_NAME: &CStr = <LocalModule as kernel::ModuleMetadata>::NAME;
+const AUXILIARY_NAME: &CStr = c_str!("auxiliary");
+
+struct AuxiliaryDriver;
+
+kernel::auxiliary_device_table!(
+ AUX_TABLE,
+ MODULE_AUX_TABLE,
+ <AuxiliaryDriver as auxiliary::Driver>::IdInfo,
+ [(auxiliary::DeviceId::new(MODULE_NAME, AUXILIARY_NAME), ())]
+);
+
+impl auxiliary::Driver for AuxiliaryDriver {
+ type IdInfo = ();
+
+ const ID_TABLE: auxiliary::IdTable<Self::IdInfo> = &AUX_TABLE;
+
+ fn probe(adev: &mut auxiliary::Device, _info: &Self::IdInfo) -> Result<Pin<KBox<Self>>> {
+ dev_info!(
+ adev.as_ref(),
+ "Probing auxiliary driver for auxiliary device with id={}\n",
+ adev.id()
+ );
+
+ let this = KBox::new(Self, GFP_KERNEL)?;
+
+ Ok(this.into())
+ }
+}
+
+struct PciDriver {
+ _reg: [auxiliary::Registration; 2],
+}
+
+kernel::pci_device_table!(
+ PCI_TABLE,
+ MODULE_PCI_TABLE,
+ <PciDriver as pci::Driver>::IdInfo,
+ [(
+ pci::DeviceId::from_id(bindings::PCI_VENDOR_ID_REDHAT, 0x5),
+ ()
+ )]
+);
+
+impl pci::Driver for PciDriver {
+ type IdInfo = ();
+
+ const ID_TABLE: pci::IdTable<Self::IdInfo> = &PCI_TABLE;
+
+ fn probe(pdev: &mut pci::Device, _info: &Self::IdInfo) -> Result<Pin<KBox<Self>>> {
+ let this = KBox::new(
+ Self {
+ _reg: [
+ auxiliary::Registration::new(pdev.as_ref(), AUXILIARY_NAME, 0, MODULE_NAME)?,
+ auxiliary::Registration::new(pdev.as_ref(), AUXILIARY_NAME, 1, MODULE_NAME)?,
+ ],
+ },
+ GFP_KERNEL,
+ )?;
+
+ Ok(this.into())
+ }
+}
+
+#[pin_data]
+struct SampleModule {
+ #[pin]
+ _pci_driver: driver::Registration<pci::Adapter<PciDriver>>,
+ #[pin]
+ _aux_driver: driver::Registration<auxiliary::Adapter<AuxiliaryDriver>>,
+}
+
+impl InPlaceModule for SampleModule {
+ fn init(module: &'static kernel::ThisModule) -> impl init::PinInit<Self, Error> {
+ try_pin_init!(Self {
+ _pci_driver <- driver::Registration::new(MODULE_NAME, module),
+ _aux_driver <- driver::Registration::new(MODULE_NAME, module),
+ })
+ }
+}
+
+module! {
+ type: SampleModule,
+ name: "rust_driver_auxiliary",
+ author: "Danilo Krummrich",
+ description: "Rust auxiliary driver",
+ license: "GPL v2",
+}
--
2.48.1
^ permalink raw reply related [flat|nested] 7+ messages in thread* Re: [PATCH 0/4] Auxiliary bus Rust abstractions
2025-03-12 0:19 [PATCH 0/4] Auxiliary bus Rust abstractions Danilo Krummrich
` (3 preceding siblings ...)
2025-03-12 0:19 ` [PATCH 4/4] samples: rust: add Rust auxiliary driver sample Danilo Krummrich
@ 2025-03-12 7:14 ` Greg KH
2025-03-12 20:09 ` Danilo Krummrich
4 siblings, 1 reply; 7+ messages in thread
From: Greg KH @ 2025-03-12 7:14 UTC (permalink / raw)
To: Danilo Krummrich
Cc: rafael, ojeda, alex.gaynor, boqun.feng, gary, bjorn3_gh,
benno.lossin, a.hindborg, aliceryhl, tmgross, airlied, acourbot,
jhubbard, linux-kernel, rust-for-linux
On Wed, Mar 12, 2025 at 01:19:06AM +0100, Danilo Krummrich wrote:
> This series adds Rust abstractions for the auxiliary bus.
>
> It implements the required abstractions to write auxiliary drivers and create
> auxiliary device registrations. A driver sample illustrates how the
> corresponding abstractions work.
>
> The auxiliary abstractions are required for the Nova driver project, in order to
> connect nova-core with the nova-drm driver.
Nice!
> This patch series depends on [1] (taken through the nova tree for v6.15); a
> branch containing the patches, including the dependency can be found in [2].
>
> [1] https://lore.kernel.org/rust-for-linux/20250306222336.23482-2-dakr@kernel.org/
> [2] https://web.git.kernel.org/pub/scm/linux/kernel/git/dakr/linux.git/log/?h=rust/auxiliary
Do you want this to wait until that lands in 6.15-rc1 or do you want to
take this now through the nova tree? Either is fine with me.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH 0/4] Auxiliary bus Rust abstractions
2025-03-12 7:14 ` [PATCH 0/4] Auxiliary bus Rust abstractions Greg KH
@ 2025-03-12 20:09 ` Danilo Krummrich
0 siblings, 0 replies; 7+ messages in thread
From: Danilo Krummrich @ 2025-03-12 20:09 UTC (permalink / raw)
To: Greg KH
Cc: rafael, ojeda, alex.gaynor, boqun.feng, gary, bjorn3_gh,
benno.lossin, a.hindborg, aliceryhl, tmgross, airlied, acourbot,
jhubbard, linux-kernel, rust-for-linux
On Wed, Mar 12, 2025 at 08:14:24AM +0100, Greg KH wrote:
> On Wed, Mar 12, 2025 at 01:19:06AM +0100, Danilo Krummrich wrote:
> > This series adds Rust abstractions for the auxiliary bus.
> >
> > It implements the required abstractions to write auxiliary drivers and create
> > auxiliary device registrations. A driver sample illustrates how the
> > corresponding abstractions work.
> >
> > The auxiliary abstractions are required for the Nova driver project, in order to
> > connect nova-core with the nova-drm driver.
>
> Nice!
>
> > This patch series depends on [1] (taken through the nova tree for v6.15); a
> > branch containing the patches, including the dependency can be found in [2].
> >
> > [1] https://lore.kernel.org/rust-for-linux/20250306222336.23482-2-dakr@kernel.org/
> > [2] https://web.git.kernel.org/pub/scm/linux/kernel/git/dakr/linux.git/log/?h=rust/auxiliary
>
> Do you want this to wait until that lands in 6.15-rc1 or do you want to
> take this now through the nova tree? Either is fine with me.
Thanks! Let's wait for things to land in Linus' tree and give people some time
to review.
I will also send a v2 soon, fixing up a soundness issue I'm also working on
a fix for platform and PCI.
^ permalink raw reply [flat|nested] 7+ messages in thread