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authorLinus Torvalds <torvalds@linux-foundation.org>2025-05-28 09:46:39 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2025-05-28 09:46:39 -0700
commitb08494a8f7416e5f09907318c5460ad6f6e2a548 (patch)
treef7c5615c5a5f02e9cb9033883938788e223a6960 /rust/kernel
parenta61e26038143727d9b0f1bc01b0370f77f2ad7e4 (diff)
parentf8bb3ed3197966fb60bedcbdc126d2bd5bc0a77f (diff)
Merge tag 'drm-next-2025-05-28' of https://gitlab.freedesktop.org/drm/kernel
Pull drm updates from Dave Airlie: "As part of building up nova-core/nova-drm pieces we've brought in some rust abstractions through this tree, aux bus being the main one, with devres changes also in the driver-core tree. Along with the drm core abstractions and enough nova-core/nova-drm to use them. This is still all stub work under construction, to build the nova driver upstream. The other big NVIDIA related one is nouveau adds support for Hopper/Blackwell GPUs, this required a new GSP firmware update to 570.144, and a bunch of rework in order to support multiple fw interfaces. There is also the introduction of an asahi uapi header file as a precursor to getting the real driver in later, but to unblock userspace mesa packages while the driver is trapped behind rust enablement. Otherwise it's the usual mixture of stuff all over, amdgpu, i915/xe, and msm being the main ones, and some changes to vsprintf. new drivers: - bring in the asahi uapi header standalone - nova-drm: stub driver rust dependencies (for nova-core): - auxiliary - bus abstractions - driver registration - sample driver - devres changes from driver-core - revocable changes core: - add Apple fourcc modifiers - add virtio capset definitions - extend EXPORT_SYNC_FILE for timeline syncobjs - convert to devm_platform_ioremap_resource - refactor shmem helper page pinning - DP powerup/down link helpers - extended %p4cc in vsprintf.c to support fourcc prints - change vsprintf %p4cn to %p4chR, remove %p4cn - Add drm_file_err function - IN_FORMATS_ASYNC property - move sitronix from tiny to their own subdir rust: - add drm core infrastructure rust abstractions (device/driver, ioctl, file, gem) dma-buf: - adjust sg handling to not cache map on attach - allow setting dma-device for import - Add a helper to sort and deduplicate dma_fence arrays docs: - updated drm scheduler docs - fbdev todo update - fb rendering - actual brightness ttm: - fix delayed destroy resv object bridge: - add kunit tests - convert tc358775 to atomic - convert drivers to devm_drm_bridge_alloc - convert rk3066_hdmi to bridge driver scheduler: - add kunit tests panel: - refcount panels to improve lifetime handling - Powertip PH128800T004-ZZA01 - NLT NL13676BC25-03F, Tianma TM070JDHG34-00 - Himax HX8279/HX8279-D DDIC - Visionox G2647FB105 - Sitronix ST7571 - ZOTAC rotation quirk vkms: - allow attaching more displays i915: - xe3lpd display updates - vrr refactor - intel_display struct conversions - xe2hpd memory type identification - add link rate/count to i915_display_info - cleanup VGA plane handling - refactor HDCP GSC - fix SLPC wait boosting reference counting - add 20ms delay to engine reset - fix fence release on early probe errors xe: - SRIOV updates - BMG PCI ID update - support separate firmware for each GT - SVM fix, prelim SVM multi-device work - export fan speed - temp disable d3cold on BMG - backup VRAM in PM notifier instead of suspend/freeze - update xe_ttm_access_memory to use GPU for non-visible access - fix guc_info debugfs for VFs - use copy_from_user instead of __copy_from_user - append PCIe gen5 limitations to xe_firmware document amdgpu: - DSC cleanup - DC Scaling updates - Fused I2C-over-AUX updates - DMUB updates - Use drm_file_err in amdgpu - Enforce isolation updates - Use new dma_fence helpers - USERQ fixes - Documentation updates - SR-IOV updates - RAS updates - PSP 12 cleanups - GC 9.5 updates - SMU 13.x updates - VCN / JPEG SR-IOV updates amdkfd: - Update error messages for SDMA - Userptr updates - XNACK fixes radeon: - CIK doorbell cleanup nouveau: - add support for NVIDIA r570 GSP firmware - enable Hopper/Blackwell support nova-core: - fix task list - register definition infrastructure - move firmware into own rust module - register auxiliary device for nova-drm nova-drm: - initial driver skeleton msm: - GPU: - ACD (adaptive clock distribution) for X1-85 - drop fictional address_space_size - improve GMU HFI response time out robustness - fix crash when throttling during boot - DPU: - use single CTL path for flushing on DPU 5.x+ - improve SSPP allocation code for better sharing - Enabled SmartDMA on SM8150, SC8180X, SC8280XP, SM8550 - Added SAR2130P support - Disabled DSC support on MSM8937, MSM8917, MSM8953, SDM660 - DP: - switch to new audio helpers - better LTTPR handling - DSI: - Added support for SA8775P - Added SAR2130P support - HDMI: - Switched to use new helpers for ACR data - Fixed old standing issue of HPD not working in some cases amdxdna: - add dma-buf support - allow empty command submits renesas: - add dma-buf support - add zpos, alpha, blend support panthor: - fail properly for NO_MMAP bos - add SET_LABEL ioctl - debugfs BO dumping support imagination: - update DT bindings - support TI AM68 GPU hibmc: - improve interrupt handling and HPD support virtio: - add panic handler support rockchip: - add RK3588 support - add DP AUX bus panel support ivpu: - add heartbeat based hangcheck mediatek: - prepares support for MT8195/99 HDMIv2/DDCv2 anx7625: - improve HPD tegra: - speed up firmware loading * tag 'drm-next-2025-05-28' of https://gitlab.freedesktop.org/drm/kernel: (1627 commits) drm/nouveau/tegra: Fix error pointer vs NULL return in nvkm_device_tegra_resource_addr() drm/xe: Default auto_link_downgrade status to false drm/xe/guc: Make creation of SLPC debugfs files conditional drm/i915/display: Add check for alloc_ordered_workqueue() and alloc_workqueue() drm/i915/dp_mst: Work around Thunderbolt sink disconnect after SINK_COUNT_ESI read drm/i915/ptl: Use everywhere the correct DDI port clock select mask drm/nouveau/kms: add support for GB20x drm/dp: add option to disable zero sized address only transactions. drm/nouveau: add support for GB20x drm/nouveau/gsp: add hal for fifo.chan.doorbell_handle drm/nouveau: add support for GB10x drm/nouveau/gf100-: track chan progress with non-WFI semaphore release drm/nouveau/nv50-: separate CHANNEL_GPFIFO handling out from CHANNEL_DMA drm/nouveau: add helper functions for allocating pinned/cpu-mapped bos drm/nouveau: add support for GH100 drm/nouveau: improve handling of 64-bit BARs drm/nouveau/gv100-: switch to volta semaphore methods drm/nouveau/gsp: support deeper page tables in COPY_SERVER_RESERVED_PDES drm/nouveau/gsp: init client VMMs with NV0080_CTRL_DMA_SET_PAGE_DIRECTORY drm/nouveau/gsp: fetch level shift and PDE from BAR2 VMM ...
Diffstat (limited to 'rust/kernel')
-rw-r--r--rust/kernel/auxiliary.rs360
-rw-r--r--rust/kernel/device.rs109
-rw-r--r--rust/kernel/devres.rs56
-rw-r--r--rust/kernel/dma.rs14
-rw-r--r--rust/kernel/drm/device.rs200
-rw-r--r--rust/kernel/drm/driver.rs166
-rw-r--r--rust/kernel/drm/file.rs99
-rw-r--r--rust/kernel/drm/gem/mod.rs328
-rw-r--r--rust/kernel/drm/ioctl.rs162
-rw-r--r--rust/kernel/drm/mod.rs19
-rw-r--r--rust/kernel/lib.rs4
-rw-r--r--rust/kernel/pci.rs55
-rw-r--r--rust/kernel/platform.rs54
-rw-r--r--rust/kernel/revocable.rs28
-rw-r--r--rust/kernel/types.rs8
15 files changed, 1595 insertions, 67 deletions
diff --git a/rust/kernel/auxiliary.rs b/rust/kernel/auxiliary.rs
new file mode 100644
index 000000000000..5c072960dee0
--- /dev/null
+++ b/rust/kernel/auxiliary.rs
@@ -0,0 +1,360 @@
+// 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::{ForeignOwnable, Opaque},
+ ThisModule,
+};
+use core::{
+ marker::PhantomData,
+ ptr::{addr_of_mut, NonNull},
+};
+
+/// 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,
+ ) -> kernel::ffi::c_int {
+ // SAFETY: The auxiliary bus only ever calls the probe callback with a valid pointer to a
+ // `struct auxiliary_device`.
+ //
+ // INVARIANT: `adev` is valid for the duration of `probe_callback()`.
+ let adev = unsafe { &*adev.cast::<Device<device::Core>>() };
+
+ // 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(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`.
+ drop(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 an auxiliary device is matches a corresponding driver.
+ fn probe(dev: &Device<device::Core>, id_info: &Self::IdInfo) -> Result<Pin<KBox<Self>>>;
+}
+
+/// The auxiliary device representation.
+///
+/// This structure represents the Rust abstraction for a C `struct auxiliary_device`. The
+/// implementation abstracts the usage of an already existing C `struct auxiliary_device` within
+/// Rust code that we get passed from the C side.
+///
+/// # Invariants
+///
+/// A [`Device`] instance represents a valid `struct auxiliary_device` created by the C portion of
+/// the kernel.
+#[repr(transparent)]
+pub struct Device<Ctx: device::DeviceContext = device::Normal>(
+ Opaque<bindings::auxiliary_device>,
+ PhantomData<Ctx>,
+);
+
+impl<Ctx: device::DeviceContext> Device<Ctx> {
+ fn as_raw(&self) -> *mut bindings::auxiliary_device {
+ self.0.get()
+ }
+
+ /// 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 }
+ }
+
+ /// Returns a reference to the parent [`device::Device`], if any.
+ pub fn parent(&self) -> Option<&device::Device> {
+ let ptr: *const Self = self;
+ // CAST: `Device<Ctx: DeviceContext>` types are transparent to each other.
+ let ptr: *const Device = ptr.cast();
+ // SAFETY: `ptr` was derived from `&self`.
+ let this = unsafe { &*ptr };
+
+ this.as_ref().parent()
+ }
+}
+
+impl Device {
+ 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()) };
+ }
+}
+
+// SAFETY: `Device` is a transparent wrapper of a type that doesn't depend on `Device`'s generic
+// argument.
+kernel::impl_device_context_deref!(unsafe { Device });
+kernel::impl_device_context_into_aref!(Device);
+
+// SAFETY: Instances of `Device` are always reference-counted.
+unsafe impl crate::types::AlwaysRefCounted for Device {
+ fn inc_ref(&self) {
+ // SAFETY: The existence of a shared reference guarantees that the refcount is non-zero.
+ unsafe { bindings::get_device(self.as_ref().as_raw()) };
+ }
+
+ unsafe fn dec_ref(obj: NonNull<Self>) {
+ // CAST: `Self` a transparent wrapper of `bindings::auxiliary_device`.
+ let adev: *mut bindings::auxiliary_device = obj.cast().as_ptr();
+
+ // SAFETY: By the type invariant of `Self`, `adev` is a pointer to a valid
+ // `struct auxiliary_device`.
+ let dev = unsafe { addr_of_mut!((*adev).dev) };
+
+ // SAFETY: The safety requirements guarantee that the refcount is non-zero.
+ unsafe { bindings::put_device(dev) }
+ }
+}
+
+impl<Ctx: device::DeviceContext> AsRef<device::Device<Ctx>> for Device<Ctx> {
+ fn as_ref(&self) -> &device::Device<Ctx> {
+ // SAFETY: By the type invariant of `Self`, `self.as_raw()` is a pointer to a valid
+ // `struct auxiliary_device`.
+ let dev = unsafe { addr_of_mut!((*self.as_raw()).dev) };
+
+ // SAFETY: `dev` points to a valid `struct device`.
+ unsafe { device::Device::as_ref(dev) }
+ }
+}
+
+// SAFETY: A `Device` is always reference-counted and can be released from any thread.
+unsafe impl Send for Device {}
+
+// SAFETY: `Device` can be shared among threads because all methods of `Device`
+// (i.e. `Device<Normal>) are thread safe.
+unsafe impl Sync for Device {}
+
+/// 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()) };
+ }
+}
+
+// SAFETY: A `Registration` of a `struct auxiliary_device` can be released from any thread.
+unsafe impl Send for Registration {}
+
+// SAFETY: `Registration` does not expose any methods or fields that need synchronization.
+unsafe impl Sync for Registration {}
diff --git a/rust/kernel/device.rs b/rust/kernel/device.rs
index 21b343a1dc4d..f08583fa39c9 100644
--- a/rust/kernel/device.rs
+++ b/rust/kernel/device.rs
@@ -9,7 +9,7 @@ use crate::{
str::CStr,
types::{ARef, Opaque},
};
-use core::{fmt, ptr};
+use core::{fmt, marker::PhantomData, ptr};
#[cfg(CONFIG_PRINTK)]
use crate::c_str;
@@ -42,7 +42,7 @@ use crate::c_str;
/// `bindings::device::release` is valid to be called from any thread, hence `ARef<Device>` can be
/// dropped from any thread.
#[repr(transparent)]
-pub struct Device(Opaque<bindings::device>);
+pub struct Device<Ctx: DeviceContext = Normal>(Opaque<bindings::device>, PhantomData<Ctx>);
impl Device {
/// Creates a new reference-counted abstraction instance of an existing `struct device` pointer.
@@ -59,12 +59,33 @@ impl Device {
// SAFETY: By the safety requirements ptr is valid
unsafe { Self::as_ref(ptr) }.into()
}
+}
+impl<Ctx: DeviceContext> Device<Ctx> {
/// Obtain the raw `struct device *`.
pub(crate) fn as_raw(&self) -> *mut bindings::device {
self.0.get()
}
+ /// Returns a reference to the parent device, if any.
+ #[cfg_attr(not(CONFIG_AUXILIARY_BUS), expect(dead_code))]
+ pub(crate) fn parent(&self) -> Option<&Self> {
+ // SAFETY:
+ // - By the type invariant `self.as_raw()` is always valid.
+ // - The parent device is only ever set at device creation.
+ let parent = unsafe { (*self.as_raw()).parent };
+
+ if parent.is_null() {
+ None
+ } else {
+ // SAFETY:
+ // - Since `parent` is not NULL, it must be a valid pointer to a `struct device`.
+ // - `parent` is valid for the lifetime of `self`, since a `struct device` holds a
+ // reference count of its parent.
+ Some(unsafe { Self::as_ref(parent) })
+ }
+ }
+
/// Convert a raw C `struct device` pointer to a `&'a Device`.
///
/// # Safety
@@ -189,6 +210,11 @@ impl Device {
}
}
+// SAFETY: `Device` is a transparent wrapper of a type that doesn't depend on `Device`'s generic
+// argument.
+kernel::impl_device_context_deref!(unsafe { Device });
+kernel::impl_device_context_into_aref!(Device);
+
// SAFETY: Instances of `Device` are always reference-counted.
unsafe impl crate::types::AlwaysRefCounted for Device {
fn inc_ref(&self) {
@@ -225,16 +251,95 @@ pub struct Normal;
/// any of the bus callbacks, such as `probe()`.
pub struct Core;
+/// The [`Bound`] context is the context of a bus specific device reference when it is guaranteed to
+/// be bound for the duration of its lifetime.
+pub struct Bound;
+
mod private {
pub trait Sealed {}
+ impl Sealed for super::Bound {}
impl Sealed for super::Core {}
impl Sealed for super::Normal {}
}
+impl DeviceContext for Bound {}
impl DeviceContext for Core {}
impl DeviceContext for Normal {}
+/// # Safety
+///
+/// The type given as `$device` must be a transparent wrapper of a type that doesn't depend on the
+/// generic argument of `$device`.
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __impl_device_context_deref {
+ (unsafe { $device:ident, $src:ty => $dst:ty }) => {
+ impl ::core::ops::Deref for $device<$src> {
+ type Target = $device<$dst>;
+
+ fn deref(&self) -> &Self::Target {
+ let ptr: *const Self = self;
+
+ // CAST: `$device<$src>` and `$device<$dst>` transparently wrap the same type by the
+ // safety requirement of the macro.
+ let ptr = ptr.cast::<Self::Target>();
+
+ // SAFETY: `ptr` was derived from `&self`.
+ unsafe { &*ptr }
+ }
+ }
+ };
+}
+
+/// Implement [`core::ops::Deref`] traits for allowed [`DeviceContext`] conversions of a (bus
+/// specific) device.
+///
+/// # Safety
+///
+/// The type given as `$device` must be a transparent wrapper of a type that doesn't depend on the
+/// generic argument of `$device`.
+#[macro_export]
+macro_rules! impl_device_context_deref {
+ (unsafe { $device:ident }) => {
+ // SAFETY: This macro has the exact same safety requirement as
+ // `__impl_device_context_deref!`.
+ ::kernel::__impl_device_context_deref!(unsafe {
+ $device,
+ $crate::device::Core => $crate::device::Bound
+ });
+
+ // SAFETY: This macro has the exact same safety requirement as
+ // `__impl_device_context_deref!`.
+ ::kernel::__impl_device_context_deref!(unsafe {
+ $device,
+ $crate::device::Bound => $crate::device::Normal
+ });
+ };
+}
+
+#[doc(hidden)]
+#[macro_export]
+macro_rules! __impl_device_context_into_aref {
+ ($src:ty, $device:tt) => {
+ impl ::core::convert::From<&$device<$src>> for $crate::types::ARef<$device> {
+ fn from(dev: &$device<$src>) -> Self {
+ (&**dev).into()
+ }
+ }
+ };
+}
+
+/// Implement [`core::convert::From`], such that all `&Device<Ctx>` can be converted to an
+/// `ARef<Device>`.
+#[macro_export]
+macro_rules! impl_device_context_into_aref {
+ ($device:tt) => {
+ ::kernel::__impl_device_context_into_aref!($crate::device::Core, $device);
+ ::kernel::__impl_device_context_into_aref!($crate::device::Bound, $device);
+ };
+}
+
#[doc(hidden)]
#[macro_export]
macro_rules! dev_printk {
diff --git a/rust/kernel/devres.rs b/rust/kernel/devres.rs
index ddb1ce4a78d9..0f79a2ec9474 100644
--- a/rust/kernel/devres.rs
+++ b/rust/kernel/devres.rs
@@ -8,7 +8,7 @@
use crate::{
alloc::Flags,
bindings,
- device::Device,
+ device::{Bound, Device},
error::{Error, Result},
ffi::c_void,
prelude::*,
@@ -45,7 +45,7 @@ struct DevresInner<T> {
/// # Example
///
/// ```no_run
-/// # use kernel::{bindings, c_str, device::Device, devres::Devres, io::{Io, IoRaw}};
+/// # use kernel::{bindings, c_str, device::{Bound, Device}, devres::Devres, io::{Io, IoRaw}};
/// # use core::ops::Deref;
///
/// // See also [`pci::Bar`] for a real example.
@@ -83,13 +83,10 @@ struct DevresInner<T> {
/// unsafe { Io::from_raw(&self.0) }
/// }
/// }
-/// # fn no_run() -> Result<(), Error> {
-/// # // SAFETY: Invalid usage; just for the example to get an `ARef<Device>` instance.
-/// # let dev = unsafe { Device::get_device(core::ptr::null_mut()) };
-///
+/// # fn no_run(dev: &Device<Bound>) -> Result<(), Error> {
/// // SAFETY: Invalid usage for example purposes.
/// let iomem = unsafe { IoMem::<{ core::mem::size_of::<u32>() }>::new(0xBAAAAAAD)? };
-/// let devres = Devres::new(&dev, iomem, GFP_KERNEL)?;
+/// let devres = Devres::new(dev, iomem, GFP_KERNEL)?;
///
/// let res = devres.try_access().ok_or(ENXIO)?;
/// res.write8(0x42, 0x0);
@@ -99,7 +96,7 @@ struct DevresInner<T> {
pub struct Devres<T>(Arc<DevresInner<T>>);
impl<T> DevresInner<T> {
- fn new(dev: &Device, data: T, flags: Flags) -> Result<Arc<DevresInner<T>>> {
+ fn new(dev: &Device<Bound>, data: T, flags: Flags) -> Result<Arc<DevresInner<T>>> {
let inner = Arc::pin_init(
pin_init!( DevresInner {
dev: dev.into(),
@@ -171,7 +168,7 @@ impl<T> DevresInner<T> {
impl<T> Devres<T> {
/// Creates a new [`Devres`] instance of the given `data`. The `data` encapsulated within the
/// returned `Devres` instance' `data` will be revoked once the device is detached.
- pub fn new(dev: &Device, data: T, flags: Flags) -> Result<Self> {
+ pub fn new(dev: &Device<Bound>, data: T, flags: Flags) -> Result<Self> {
let inner = DevresInner::new(dev, data, flags)?;
Ok(Devres(inner))
@@ -179,11 +176,50 @@ impl<T> Devres<T> {
/// Same as [`Devres::new`], but does not return a `Devres` instance. Instead the given `data`
/// is owned by devres and will be revoked / dropped, once the device is detached.
- pub fn new_foreign_owned(dev: &Device, data: T, flags: Flags) -> Result {
+ pub fn new_foreign_owned(dev: &Device<Bound>, data: T, flags: Flags) -> Result {
let _ = DevresInner::new(dev, data, flags)?;
Ok(())
}
+
+ /// Obtain `&'a T`, bypassing the [`Revocable`].
+ ///
+ /// This method allows to directly obtain a `&'a T`, bypassing the [`Revocable`], by presenting
+ /// a `&'a Device<Bound>` of the same [`Device`] this [`Devres`] instance has been created with.
+ ///
+ /// # Errors
+ ///
+ /// An error is returned if `dev` does not match the same [`Device`] this [`Devres`] instance
+ /// has been created with.
+ ///
+ /// # Example
+ ///
+ /// ```no_run
+ /// # #![cfg(CONFIG_PCI)]
+ /// # use kernel::{device::Core, devres::Devres, pci};
+ ///
+ /// fn from_core(dev: &pci::Device<Core>, devres: Devres<pci::Bar<0x4>>) -> Result {
+ /// let bar = devres.access(dev.as_ref())?;
+ ///
+ /// let _ = bar.read32(0x0);
+ ///
+ /// // might_sleep()
+ ///
+ /// bar.write32(0x42, 0x0);
+ ///
+ /// Ok(())
+ /// }
+ /// ```
+ pub fn access<'a>(&'a self, dev: &'a Device<Bound>) -> Result<&'a T> {
+ if self.0.dev.as_raw() != dev.as_raw() {
+ return Err(EINVAL);
+ }
+
+ // SAFETY: `dev` being the same device as the device this `Devres` has been created for
+ // proves that `self.0.data` hasn't been revoked and is guaranteed to not be revoked as
+ // long as `dev` lives; `dev` lives at least as long as `self`.
+ Ok(unsafe { self.deref().access() })
+ }
}
impl<T> Deref for Devres<T> {
diff --git a/rust/kernel/dma.rs b/rust/kernel/dma.rs
index 8cdc76043ee7..605e01e35715 100644
--- a/rust/kernel/dma.rs
+++ b/rust/kernel/dma.rs
@@ -6,7 +6,7 @@
use crate::{
bindings, build_assert,
- device::Device,
+ device::{Bound, Device},
error::code::*,
error::Result,
transmute::{AsBytes, FromBytes},
@@ -22,10 +22,10 @@ use crate::{
/// # Examples
///
/// ```
-/// use kernel::device::Device;
+/// # use kernel::device::{Bound, Device};
/// use kernel::dma::{attrs::*, CoherentAllocation};
///
-/// # fn test(dev: &Device) -> Result {
+/// # fn test(dev: &Device<Bound>) -> Result {
/// let attribs = DMA_ATTR_FORCE_CONTIGUOUS | DMA_ATTR_NO_WARN;
/// let c: CoherentAllocation<u64> =
/// CoherentAllocation::alloc_attrs(dev, 4, GFP_KERNEL, attribs)?;
@@ -143,16 +143,16 @@ impl<T: AsBytes + FromBytes> CoherentAllocation<T> {
/// # Examples
///
/// ```
- /// use kernel::device::Device;
+ /// # use kernel::device::{Bound, Device};
/// use kernel::dma::{attrs::*, CoherentAllocation};
///
- /// # fn test(dev: &Device) -> Result {
+ /// # fn test(dev: &Device<Bound>) -> Result {
/// let c: CoherentAllocation<u64> =
/// CoherentAllocation::alloc_attrs(dev, 4, GFP_KERNEL, DMA_ATTR_NO_WARN)?;
/// # Ok::<(), Error>(()) }
/// ```
pub fn alloc_attrs(
- dev: &Device,
+ dev: &Device<Bound>,
count: usize,
gfp_flags: kernel::alloc::Flags,
dma_attrs: Attrs,
@@ -194,7 +194,7 @@ impl<T: AsBytes + FromBytes> CoherentAllocation<T> {
/// Performs the same functionality as [`CoherentAllocation::alloc_attrs`], except the
/// `dma_attrs` is 0 by default.
pub fn alloc_coherent(
- dev: &Device,
+ dev: &Device<Bound>,
count: usize,
gfp_flags: kernel::alloc::Flags,
) -> Result<CoherentAllocation<T>> {
diff --git a/rust/kernel/drm/device.rs b/rust/kernel/drm/device.rs
new file mode 100644
index 000000000000..74c9a3dd719e
--- /dev/null
+++ b/rust/kernel/drm/device.rs
@@ -0,0 +1,200 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+
+//! DRM device.
+//!
+//! C header: [`include/linux/drm/drm_device.h`](srctree/include/linux/drm/drm_device.h)
+
+use crate::{
+ bindings, device, drm,
+ drm::driver::AllocImpl,
+ error::from_err_ptr,
+ error::Result,
+ prelude::*,
+ types::{ARef, AlwaysRefCounted, Opaque},
+};
+use core::{mem, ops::Deref, ptr, ptr::NonNull};
+
+#[cfg(CONFIG_DRM_LEGACY)]
+macro_rules! drm_legacy_fields {
+ ( $($field:ident: $val:expr),* $(,)? ) => {
+ bindings::drm_driver {
+ $( $field: $val ),*,
+ firstopen: None,
+ preclose: None,
+ dma_ioctl: None,
+ dma_quiescent: None,
+ context_dtor: None,
+ irq_handler: None,
+ irq_preinstall: None,
+ irq_postinstall: None,
+ irq_uninstall: None,
+ get_vblank_counter: None,
+ enable_vblank: None,
+ disable_vblank: None,
+ dev_priv_size: 0,
+ }
+ }
+}
+
+#[cfg(not(CONFIG_DRM_LEGACY))]
+macro_rules! drm_legacy_fields {
+ ( $($field:ident: $val:expr),* $(,)? ) => {
+ bindings::drm_driver {
+ $( $field: $val ),*
+ }
+ }
+}
+
+/// A typed DRM device with a specific `drm::Driver` implementation.
+///
+/// The device is always reference-counted.
+///
+/// # Invariants
+///
+/// `self.dev` is a valid instance of a `struct device`.
+#[repr(C)]
+#[pin_data]
+pub struct Device<T: drm::Driver> {
+ dev: Opaque<bindings::drm_device>,
+ #[pin]
+ data: T::Data,
+}
+
+impl<T: drm::Driver> Device<T> {
+ const VTABLE: bindings::drm_driver = drm_legacy_fields! {
+ load: None,
+ open: Some(drm::File::<T::File>::open_callback),
+ postclose: Some(drm::File::<T::File>::postclose_callback),
+ unload: None,
+ release: None,
+ master_set: None,
+ master_drop: None,
+ debugfs_init: None,
+ gem_create_object: T::Object::ALLOC_OPS.gem_create_object,
+ prime_handle_to_fd: T::Object::ALLOC_OPS.prime_handle_to_fd,
+ prime_fd_to_handle: T::Object::ALLOC_OPS.prime_fd_to_handle,
+ gem_prime_import: T::Object::ALLOC_OPS.gem_prime_import,
+ gem_prime_import_sg_table: T::Object::ALLOC_OPS.gem_prime_import_sg_table,
+ dumb_create: T::Object::ALLOC_OPS.dumb_create,
+ dumb_map_offset: T::Object::ALLOC_OPS.dumb_map_offset,
+ show_fdinfo: None,
+ fbdev_probe: None,
+
+ major: T::INFO.major,
+ minor: T::INFO.minor,
+ patchlevel: T::INFO.patchlevel,
+ name: T::INFO.name.as_char_ptr() as *mut _,
+ desc: T::INFO.desc.as_char_ptr() as *mut _,
+
+ driver_features: drm::driver::FEAT_GEM,
+ ioctls: T::IOCTLS.as_ptr(),
+ num_ioctls: T::IOCTLS.len() as i32,
+ fops: &Self::GEM_FOPS as _,
+ };
+
+ const GEM_FOPS: bindings::file_operations = drm::gem::create_fops();
+
+ /// Create a new `drm::Device` for a `drm::Driver`.
+ pub fn new(dev: &device::Device, data: impl PinInit<T::Data, Error>) -> Result<ARef<Self>> {
+ // SAFETY:
+ // - `VTABLE`, as a `const` is pinned to the read-only section of the compilation,
+ // - `dev` is valid by its type invarants,
+ let raw_drm: *mut Self = unsafe {
+ bindings::__drm_dev_alloc(
+ dev.as_raw(),
+ &Self::VTABLE,
+ mem::size_of::<Self>(),
+ mem::offset_of!(Self, dev),
+ )
+ }
+ .cast();
+ let raw_drm = NonNull::new(from_err_ptr(raw_drm)?).ok_or(ENOMEM)?;
+
+ // SAFETY: `raw_drm` is a valid pointer to `Self`.
+ let raw_data = unsafe { ptr::addr_of_mut!((*raw_drm.as_ptr()).data) };
+
+ // SAFETY:
+ // - `raw_data` is a valid pointer to uninitialized memory.
+ // - `raw_data` will not move until it is dropped.
+ unsafe { data.__pinned_init(raw_data) }.inspect_err(|_| {
+ // SAFETY: `__drm_dev_alloc()` was successful, hence `raw_drm` must be valid and the
+ // refcount must be non-zero.
+ unsafe { bindings::drm_dev_put(ptr::addr_of_mut!((*raw_drm.as_ptr()).dev).cast()) };
+ })?;
+
+ // SAFETY: The reference count is one, and now we take ownership of that reference as a
+ // `drm::Device`.
+ Ok(unsafe { ARef::from_raw(raw_drm) })
+ }
+
+ pub(crate) fn as_raw(&self) -> *mut bindings::drm_device {
+ self.dev.get()
+ }
+
+ /// # Safety
+ ///
+ /// `ptr` must be a valid pointer to a `struct device` embedded in `Self`.
+ unsafe fn from_drm_device(ptr: *const bindings::drm_device) -> *mut Self {
+ // SAFETY: By the safety requirements of this function `ptr` is a valid pointer to a
+ // `struct drm_device` embedded in `Self`.
+ unsafe { crate::container_of!(ptr, Self, dev) }.cast_mut()
+ }
+
+ /// Not intended to be called externally, except via declare_drm_ioctls!()
+ ///
+ /// # Safety
+ ///
+ /// Callers must ensure that `ptr` is valid, non-null, and has a non-zero reference count,
+ /// i.e. it must be ensured that the reference count of the C `struct drm_device` `ptr` points
+ /// to can't drop to zero, for the duration of this function call and the entire duration when
+ /// the returned reference exists.
+ ///
+ /// Additionally, callers must ensure that the `struct device`, `ptr` is pointing to, is
+ /// embedded in `Self`.
+ #[doc(hidden)]
+ pub unsafe fn as_ref<'a>(ptr: *const bindings::drm_device) -> &'a Self {
+ // SAFETY: By the safety requirements of this function `ptr` is a valid pointer to a
+ // `struct drm_device` embedded in `Self`.
+ let ptr = unsafe { Self::from_drm_device(ptr) };
+
+ // SAFETY: `ptr` is valid by the safety requirements of this function.
+ unsafe { &*ptr.cast() }
+ }
+}
+
+impl<T: drm::Driver> Deref for Device<T> {
+ type Target = T::Data;
+
+ fn deref(&self) -> &Self::Target {
+ &self.data
+ }
+}
+
+// SAFETY: DRM device objects are always reference counted and the get/put functions
+// satisfy the requirements.
+unsafe impl<T: drm::Driver> AlwaysRefCounted for Device<T> {
+ fn inc_ref(&self) {
+ // SAFETY: The existence of a shared reference guarantees that the refcount is non-zero.
+ unsafe { bindings::drm_dev_get(self.as_raw()) };
+ }
+
+ unsafe fn dec_ref(obj: NonNull<Self>) {
+ // SAFETY: The safety requirements guarantee that the refcount is non-zero.
+ unsafe { bindings::drm_dev_put(obj.cast().as_ptr()) };
+ }
+}
+
+impl<T: drm::Driver> AsRef<device::Device> for Device<T> {
+ fn as_ref(&self) -> &device::Device {
+ // SAFETY: `bindings::drm_device::dev` is valid as long as the DRM device itself is valid,
+ // which is guaranteed by the type invariant.
+ unsafe { device::Device::as_ref((*self.as_raw()).dev) }
+ }
+}
+
+// SAFETY: A `drm::Device` can be released from any thread.
+unsafe impl<T: drm::Driver> Send for Device<T> {}
+
+// SAFETY: A `drm::Device` can be shared among threads because all immutable methods are protected
+// by the synchronization in `struct drm_device`.
+unsafe impl<T: drm::Driver> Sync for Device<T> {}
diff --git a/rust/kernel/drm/driver.rs b/rust/kernel/drm/driver.rs
new file mode 100644
index 000000000000..acb638086131
--- /dev/null
+++ b/rust/kernel/drm/driver.rs
@@ -0,0 +1,166 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+
+//! DRM driver core.
+//!
+//! C header: [`include/linux/drm/drm_drv.h`](srctree/include/linux/drm/drm_drv.h)
+
+use crate::{
+ bindings, device,
+ devres::Devres,
+ drm,
+ error::{to_result, Result},
+ prelude::*,
+ str::CStr,
+ types::ARef,
+};
+use macros::vtable;
+
+/// Driver use the GEM memory manager. This should be set for all modern drivers.
+pub(crate) const FEAT_GEM: u32 = bindings::drm_driver_feature_DRIVER_GEM;
+
+/// Information data for a DRM Driver.
+pub struct DriverInfo {
+ /// Driver major version.
+ pub major: i32,
+ /// Driver minor version.
+ pub minor: i32,
+ /// Driver patchlevel version.
+ pub patchlevel: i32,
+ /// Driver name.
+ pub name: &'static CStr,
+ /// Driver description.
+ pub desc: &'static CStr,
+}
+
+/// Internal memory management operation set, normally created by memory managers (e.g. GEM).
+pub struct AllocOps {
+ pub(crate) gem_create_object: Option<
+ unsafe extern "C" fn(
+ dev: *mut bindings::drm_device,
+ size: usize,
+ ) -> *mut bindings::drm_gem_object,
+ >,
+ pub(crate) prime_handle_to_fd: Option<
+ unsafe extern "C" fn(
+ dev: *mut bindings::drm_device,
+ file_priv: *mut bindings::drm_file,
+ handle: u32,
+ flags: u32,
+ prime_fd: *mut core::ffi::c_int,
+ ) -> core::ffi::c_int,
+ >,
+ pub(crate) prime_fd_to_handle: Option<
+ unsafe extern "C" fn(
+ dev: *mut bindings::drm_device,
+ file_priv: *mut bindings::drm_file,
+ prime_fd: core::ffi::c_int,
+ handle: *mut u32,
+ ) -> core::ffi::c_int,
+ >,
+ pub(crate) gem_prime_import: Option<
+ unsafe extern "C" fn(
+ dev: *mut bindings::drm_device,
+ dma_buf: *mut bindings::dma_buf,
+ ) -> *mut bindings::drm_gem_object,
+ >,
+ pub(crate) gem_prime_import_sg_table: Option<
+ unsafe extern "C" fn(
+ dev: *mut bindings::drm_device,
+ attach: *mut bindings::dma_buf_attachment,
+ sgt: *mut bindings::sg_table,
+ ) -> *mut bindings::drm_gem_object,
+ >,
+ pub(crate) dumb_create: Option<
+ unsafe extern "C" fn(
+ file_priv: *mut bindings::drm_file,
+ dev: *mut bindings::drm_device,
+ args: *mut bindings::drm_mode_create_dumb,
+ ) -> core::ffi::c_int,
+ >,
+ pub(crate) dumb_map_offset: Option<
+ unsafe extern "C" fn(
+ file_priv: *mut bindings::drm_file,
+ dev: *mut bindings::drm_device,
+ handle: u32,
+ offset: *mut u64,
+ ) -> core::ffi::c_int,
+ >,
+}
+
+/// Trait for memory manager implementations. Implemented internally.
+pub trait AllocImpl: super::private::Sealed + drm::gem::IntoGEMObject {
+ /// The C callback operations for this memory manager.
+ const ALLOC_OPS: AllocOps;
+}
+
+/// The DRM `Driver` trait.
+///
+/// This trait must be implemented by drivers in order to create a `struct drm_device` and `struct
+/// drm_driver` to be registered in the DRM subsystem.
+#[vtable]
+pub trait Driver {
+ /// Context data associated with the DRM driver
+ type Data: Sync + Send;
+
+ /// The type used to manage memory for this driver.
+ type Object: AllocImpl;
+
+ /// The type used to represent a DRM File (client)
+ type File: drm::file::DriverFile;
+
+ /// Driver metadata
+ const INFO: DriverInfo;
+
+ /// IOCTL list. See `kernel::drm::ioctl::declare_drm_ioctls!{}`.
+ const IOCTLS: &'static [drm::ioctl::DrmIoctlDescriptor];
+}
+
+/// The registration type of a `drm::Device`.
+///
+/// Once the `Registration` structure is dropped, the device is unregistered.
+pub struct Registration<T: Driver>(ARef<drm::Device<T>>);
+
+impl<T: Driver> Registration<T> {
+ /// Creates a new [`Registration`] and registers it.
+ fn new(drm: &drm::Device<T>, flags: usize) -> Result<Self> {
+ // SAFETY: `drm.as_raw()` is valid by the invariants of `drm::Device`.
+ to_result(unsafe { bindings::drm_dev_register(drm.as_raw(), flags) })?;
+
+ Ok(Self(drm.into()))
+ }
+
+ /// Same as [`Registration::new`}, but transfers ownership of the [`Registration`] to
+ /// [`Devres`].
+ pub fn new_foreign_owned(
+ drm: &drm::Device<T>,
+ dev: &device::Device<device::Bound>,
+ flags: usize,
+ ) -> Result {
+ if drm.as_ref().as_raw() != dev.as_raw() {
+ return Err(EINVAL);
+ }
+
+ let reg = Registration::<T>::new(drm, flags)?;
+ Devres::new_foreign_owned(dev, reg, GFP_KERNEL)
+ }
+
+ /// Returns a reference to the `Device` instance for this registration.
+ pub fn device(&self) -> &drm::Device<T> {
+ &self.0
+ }
+}
+
+// SAFETY: `Registration` doesn't offer any methods or access to fields when shared between
+// threads, hence it's safe to share it.
+unsafe impl<T: Driver> Sync for Registration<T> {}
+
+// SAFETY: Registration with and unregistration from the DRM subsystem can happen from any thread.
+unsafe impl<T: Driver> Send for Registration<T> {}
+
+impl<T: Driver> Drop for Registration<T> {
+ fn drop(&mut self) {
+ // SAFETY: Safe by the invariant of `ARef<drm::Device<T>>`. The existence of this
+ // `Registration` also guarantees the this `drm::Device` is actually registered.
+ unsafe { bindings::drm_dev_unregister(self.0.as_raw()) };
+ }
+}
diff --git a/rust/kernel/drm/file.rs b/rust/kernel/drm/file.rs
new file mode 100644
index 000000000000..b9527705e551
--- /dev/null
+++ b/rust/kernel/drm/file.rs
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+
+//! DRM File objects.
+//!
+//! C header: [`include/linux/drm/drm_file.h`](srctree/include/linux/drm/drm_file.h)
+
+use crate::{bindings, drm, error::Result, prelude::*, types::Opaque};
+use core::marker::PhantomData;
+use core::pin::Pin;
+
+/// Trait that must be implemented by DRM drivers to represent a DRM File (a client instance).
+pub trait DriverFile {
+ /// The parent `Driver` implementation for this `DriverFile`.
+ type Driver: drm::Driver;
+
+ /// Open a new file (called when a client opens the DRM device).
+ fn open(device: &drm::Device<Self::Driver>) -> Result<Pin<KBox<Self>>>;
+}
+
+/// An open DRM File.
+///
+/// # Invariants
+///
+/// `self.0` is a valid instance of a `struct drm_file`.
+#[repr(transparent)]
+pub struct File<T: DriverFile>(Opaque<bindings::drm_file>, PhantomData<T>);
+
+impl<T: DriverFile> File<T> {
+ #[doc(hidden)]
+ /// Not intended to be called externally, except via declare_drm_ioctls!()
+ ///
+ /// # Safety
+ ///
+ /// `raw_file` must be a valid pointer to an open `struct drm_file`, opened through `T::open`.
+ pub unsafe fn as_ref<'a>(ptr: *mut bindings::drm_file) -> &'a File<T> {
+ // SAFETY: `raw_file` is valid by the safety requirements of this function.
+ unsafe { &*ptr.cast() }
+ }
+
+ pub(super) fn as_raw(&self) -> *mut bindings::drm_file {
+ self.0.get()
+ }
+
+ fn driver_priv(&self) -> *mut T {
+ // SAFETY: By the type invariants of `Self`, `self.as_raw()` is always valid.
+ unsafe { (*self.as_raw()).driver_priv }.cast()
+ }
+
+ /// Return a pinned reference to the driver file structure.
+ pub fn inner(&self) -> Pin<&T> {
+ // SAFETY: By the type invariant the pointer `self.as_raw()` points to a valid and opened
+ // `struct drm_file`, hence `driver_priv` has been properly initialized by `open_callback`.
+ unsafe { Pin::new_unchecked(&*(self.driver_priv())) }
+ }
+
+ /// The open callback of a `struct drm_file`.
+ pub(crate) extern "C" fn open_callback(
+ raw_dev: *mut bindings::drm_device,
+ raw_file: *mut bindings::drm_file,
+ ) -> core::ffi::c_int {
+ // SAFETY: A callback from `struct drm_driver::open` guarantees that
+ // - `raw_dev` is valid pointer to a `struct drm_device`,
+ // - the corresponding `struct drm_device` has been registered.
+ let drm = unsafe { drm::Device::as_ref(raw_dev) };
+
+ // SAFETY: `raw_file` is a valid pointer to a `struct drm_file`.
+ let file = unsafe { File::<T>::as_ref(raw_file) };
+
+ let inner = match T::open(drm) {
+ Err(e) => {
+ return e.to_errno();
+ }
+ Ok(i) => i,
+ };
+
+ // SAFETY: This pointer is treated as pinned, and the Drop guarantee is upheld in
+ // `postclose_callback()`.
+ let driver_priv = KBox::into_raw(unsafe { Pin::into_inner_unchecked(inner) });
+
+ // SAFETY: By the type invariants of `Self`, `self.as_raw()` is always valid.
+ unsafe { (*file.as_raw()).driver_priv = driver_priv.cast() };
+
+ 0
+ }
+
+ /// The postclose callback of a `struct drm_file`.
+ pub(crate) extern "C" fn postclose_callback(
+ _raw_dev: *mut bindings::drm_device,
+ raw_file: *mut bindings::drm_file,
+ ) {
+ // SAFETY: This reference won't escape this function
+ let file = unsafe { File::<T>::as_ref(raw_file) };
+
+ // SAFETY: `file.driver_priv` has been created in `open_callback` through `KBox::into_raw`.
+ let _ = unsafe { KBox::from_raw(file.driver_priv()) };
+ }
+}
+
+impl<T: DriverFile> super::private::Sealed for File<T> {}
diff --git a/rust/kernel/drm/gem/mod.rs b/rust/kernel/drm/gem/mod.rs
new file mode 100644
index 000000000000..d8765e61c6c2
--- /dev/null
+++ b/rust/kernel/drm/gem/mod.rs
@@ -0,0 +1,328 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+
+//! DRM GEM API
+//!
+//! C header: [`include/linux/drm/drm_gem.h`](srctree/include/linux/drm/drm_gem.h)
+
+use crate::{
+ alloc::flags::*,
+ bindings, drm,
+ drm::driver::{AllocImpl, AllocOps},
+ error::{to_result, Result},
+ prelude::*,
+ types::{ARef, AlwaysRefCounted, Opaque},
+};
+use core::{mem, ops::Deref, ptr::NonNull};
+
+/// GEM object functions, which must be implemented by drivers.
+pub trait BaseDriverObject<T: BaseObject>: Sync + Send + Sized {
+ /// Create a new driver data object for a GEM object of a given size.
+ fn new(dev: &drm::Device<T::Driver>, size: usize) -> impl PinInit<Self, Error>;
+
+ /// Open a new handle to an existing object, associated with a File.
+ fn open(
+ _obj: &<<T as IntoGEMObject>::Driver as drm::Driver>::Object,
+ _file: &drm::File<<<T as IntoGEMObject>::Driver as drm::Driver>::File>,
+ ) -> Result {
+ Ok(())
+ }
+
+ /// Close a handle to an existing object, associated with a File.
+ fn close(
+ _obj: &<<T as IntoGEMObject>::Driver as drm::Driver>::Object,
+ _file: &drm::File<<<T as IntoGEMObject>::Driver as drm::Driver>::File>,
+ ) {
+ }
+}
+
+/// Trait that represents a GEM object subtype
+pub trait IntoGEMObject: Sized + super::private::Sealed + AlwaysRefCounted {
+ /// Owning driver for this type
+ type Driver: drm::Driver;
+
+ /// Returns a reference to the raw `drm_gem_object` structure, which must be valid as long as
+ /// this owning object is valid.
+ fn as_raw(&self) -> *mut bindings::drm_gem_object;
+
+ /// Converts a pointer to a `struct drm_gem_object` into a reference to `Self`.
+ ///
+ /// # Safety
+ ///
+ /// - `self_ptr` must be a valid pointer to `Self`.
+ /// - The caller promises that holding the immutable reference returned by this function does
+ /// not violate rust's data aliasing rules and remains valid throughout the lifetime of `'a`.
+ unsafe fn as_ref<'a>(self_ptr: *mut bindings::drm_gem_object) -> &'a Self;
+}
+
+// SAFETY: All gem objects are refcounted.
+unsafe impl<T: IntoGEMObject> AlwaysRefCounted for T {
+ fn inc_ref(&self) {
+ // SAFETY: The existence of a shared reference guarantees that the refcount is non-zero.
+ unsafe { bindings::drm_gem_object_get(self.as_raw()) };
+ }
+
+ unsafe fn dec_ref(obj: NonNull<Self>) {
+ // SAFETY: We either hold the only refcount on `obj`, or one of many - meaning that no one
+ // else could possibly hold a mutable reference to `obj` and thus this immutable reference
+ // is safe.
+ let obj = unsafe { obj.as_ref() }.as_raw();
+
+ // SAFETY:
+ // - The safety requirements guarantee that the refcount is non-zero.
+ // - We hold no references to `obj` now, making it safe for us to potentially deallocate it.
+ unsafe { bindings::drm_gem_object_put(obj) };
+ }
+}
+
+/// Trait which must be implemented by drivers using base GEM objects.
+pub trait DriverObject: BaseDriverObject<Object<Self>> {
+ /// Parent `Driver` for this object.
+ type Driver: drm::Driver;
+}
+
+extern "C" fn open_callback<T: BaseDriverObject<U>, U: BaseObject>(
+ raw_obj: *mut bindings::drm_gem_object,
+ raw_file: *mut bindings::drm_file,
+) -> core::ffi::c_int {
+ // SAFETY: `open_callback` is only ever called with a valid pointer to a `struct drm_file`.
+ let file = unsafe {
+ drm::File::<<<U as IntoGEMObject>::Driver as drm::Driver>::File>::as_ref(raw_file)
+ };
+ // SAFETY: `open_callback` is specified in the AllocOps structure for `Object<T>`, ensuring that
+ // `raw_obj` is indeed contained within a `Object<T>`.
+ let obj = unsafe {
+ <<<U as IntoGEMObject>::Driver as drm::Driver>::Object as IntoGEMObject>::as_ref(raw_obj)
+ };
+
+ match T::open(obj, file) {
+ Err(e) => e.to_errno(),
+ Ok(()) => 0,
+ }
+}
+
+extern "C" fn close_callback<T: BaseDriverObject<U>, U: BaseObject>(
+ raw_obj: *mut bindings::drm_gem_object,
+ raw_file: *mut bindings::drm_file,
+) {
+ // SAFETY: `open_callback` is only ever called with a valid pointer to a `struct drm_file`.
+ let file = unsafe {
+ drm::File::<<<U as IntoGEMObject>::Driver as drm::Driver>::File>::as_ref(raw_file)
+ };
+ // SAFETY: `close_callback` is specified in the AllocOps structure for `Object<T>`, ensuring
+ // that `raw_obj` is indeed contained within a `Object<T>`.
+ let obj = unsafe {
+ <<<U as IntoGEMObject>::Driver as drm::Driver>::Object as IntoGEMObject>::as_ref(raw_obj)
+ };
+
+ T::close(obj, file);
+}
+
+impl<T: DriverObject> IntoGEMObject for Object<T> {
+ type Driver = T::Driver;
+
+ fn as_raw(&self) -> *mut bindings::drm_gem_object {
+ self.obj.get()
+ }
+
+ unsafe fn as_ref<'a>(self_ptr: *mut bindings::drm_gem_object) -> &'a Self {
+ // SAFETY: `obj` is guaranteed to be in an `Object<T>` via the safety contract of this
+ // function
+ unsafe { &*crate::container_of!(self_ptr, Object<T>, obj) }
+ }
+}
+
+/// Base operations shared by all GEM object classes
+pub trait BaseObject: IntoGEMObject {
+ /// Returns the size of the object in bytes.
+ fn size(&self) -> usize {
+ // SAFETY: `self.as_raw()` is guaranteed to be a pointer to a valid `struct drm_gem_object`.
+ unsafe { (*self.as_raw()).size }
+ }
+
+ /// Creates a new handle for the object associated with a given `File`
+ /// (or returns an existing one).
+ fn create_handle(
+ &self,
+ file: &drm::File<<<Self as IntoGEMObject>::Driver as drm::Driver>::File>,
+ ) -> Result<u32> {
+ let mut handle: u32 = 0;
+ // SAFETY: The arguments are all valid per the type invariants.
+ to_result(unsafe {
+ bindings::drm_gem_handle_create(file.as_raw().cast(), self.as_raw(), &mut handle)
+ })?;
+ Ok(handle)
+ }
+
+ /// Looks up an object by its handle for a given `File`.
+ fn lookup_handle(
+ file: &drm::File<<<Self as IntoGEMObject>::Driver as drm::Driver>::File>,
+ handle: u32,
+ ) -> Result<ARef<Self>> {
+ // SAFETY: The arguments are all valid per the type invariants.
+ let ptr = unsafe { bindings::drm_gem_object_lookup(file.as_raw().cast(), handle) };
+ if ptr.is_null() {
+ return Err(ENOENT);
+ }
+
+ // SAFETY:
+ // - A `drm::Driver` can only have a single `File` implementation.
+ // - `file` uses the same `drm::Driver` as `Self`.
+ // - Therefore, we're guaranteed that `ptr` must be a gem object embedded within `Self`.
+ // - And we check if the pointer is null befoe calling as_ref(), ensuring that `ptr` is a
+ // valid pointer to an initialized `Self`.
+ let obj = unsafe { Self::as_ref(ptr) };
+
+ // SAFETY:
+ // - We take ownership of the reference of `drm_gem_object_lookup()`.
+ // - Our `NonNull` comes from an immutable reference, thus ensuring it is a valid pointer to
+ // `Self`.
+ Ok(unsafe { ARef::from_raw(obj.into()) })
+ }
+
+ /// Creates an mmap offset to map the object from userspace.
+ fn create_mmap_offset(&self) -> Result<u64> {
+ // SAFETY: The arguments are valid per the type invariant.
+ to_result(unsafe { bindings::drm_gem_create_mmap_offset(self.as_raw()) })?;
+
+ // SAFETY: The arguments are valid per the type invariant.
+ Ok(unsafe { bindings::drm_vma_node_offset_addr(&raw mut (*self.as_raw()).vma_node) })
+ }
+}
+
+impl<T: IntoGEMObject> BaseObject for T {}
+
+/// A base GEM object.
+///
+/// Invariants
+///
+/// - `self.obj` is a valid instance of a `struct drm_gem_object`.
+/// - `self.dev` is always a valid pointer to a `struct drm_device`.
+#[repr(C)]
+#[pin_data]
+pub struct Object<T: DriverObject + Send + Sync> {
+ obj: Opaque<bindings::drm_gem_object>,
+ dev: NonNull<drm::Device<T::Driver>>,
+ #[pin]
+ data: T,
+}
+
+impl<T: DriverObject> Object<T> {
+ /// The size of this object's structure.
+ pub const SIZE: usize = mem::size_of::<Self>();
+
+ const OBJECT_FUNCS: bindings::drm_gem_object_funcs = bindings::drm_gem_object_funcs {
+ free: Some(Self::free_callback),
+ open: Some(open_callback::<T, Object<T>>),
+ close: Some(close_callback::<T, Object<T>>),
+ print_info: None,
+ export: None,
+ pin: None,
+ unpin: None,
+ get_sg_table: None,
+ vmap: None,
+ vunmap: None,
+ mmap: None,
+ status: None,
+ vm_ops: core::ptr::null_mut(),
+ evict: None,
+ rss: None,
+ };
+
+ /// Create a new GEM object.
+ pub fn new(dev: &drm::Device<T::Driver>, size: usize) -> Result<ARef<Self>> {
+ let obj: Pin<KBox<Self>> = KBox::pin_init(
+ try_pin_init!(Self {
+ obj: Opaque::new(bindings::drm_gem_object::default()),
+ data <- T::new(dev, size),
+ // INVARIANT: The drm subsystem guarantees that the `struct drm_device` will live
+ // as long as the GEM object lives.
+ dev: dev.into(),
+ }),
+ GFP_KERNEL,
+ )?;
+
+ // SAFETY: `obj.as_raw()` is guaranteed to be valid by the initialization above.
+ unsafe { (*obj.as_raw()).funcs = &Self::OBJECT_FUNCS };
+
+ // SAFETY: The arguments are all valid per the type invariants.
+ to_result(unsafe { bindings::drm_gem_object_init(dev.as_raw(), obj.obj.get(), size) })?;
+
+ // SAFETY: We never move out of `Self`.
+ let ptr = KBox::into_raw(unsafe { Pin::into_inner_unchecked(obj) });
+
+ // SAFETY: `ptr` comes from `KBox::into_raw` and hence can't be NULL.
+ let ptr = unsafe { NonNull::new_unchecked(ptr) };
+
+ // SAFETY: We take over the initial reference count from `drm_gem_object_init()`.
+ Ok(unsafe { ARef::from_raw(ptr) })
+ }
+
+ /// Returns the `Device` that owns this GEM object.
+ pub fn dev(&self) -> &drm::Device<T::Driver> {
+ // SAFETY: The DRM subsystem guarantees that the `struct drm_device` will live as long as
+ // the GEM object lives, hence the pointer must be valid.
+ unsafe { self.dev.as_ref() }
+ }
+
+ fn as_raw(&self) -> *mut bindings::drm_gem_object {
+ self.obj.get()
+ }
+
+ extern "C" fn free_callback(obj: *mut bindings::drm_gem_object) {
+ // SAFETY: All of our objects are of type `Object<T>`.
+ let this = unsafe { crate::container_of!(obj, Self, obj) }.cast_mut();
+
+ // SAFETY: The C code only ever calls this callback with a valid pointer to a `struct
+ // drm_gem_object`.
+ unsafe { bindings::drm_gem_object_release(obj) };
+
+ // SAFETY: All of our objects are allocated via `KBox`, and we're in the
+ // free callback which guarantees this object has zero remaining references,
+ // so we can drop it.
+ let _ = unsafe { KBox::from_raw(this) };
+ }
+}
+
+impl<T: DriverObject> super::private::Sealed for Object<T> {}
+
+impl<T: DriverObject> Deref for Object<T> {
+ type Target = T;
+
+ fn deref(&self) -> &Self::Target {
+ &self.data
+ }
+}
+
+impl<T: DriverObject> AllocImpl for Object<T> {
+ const ALLOC_OPS: AllocOps = AllocOps {
+ gem_create_object: None,
+ prime_handle_to_fd: None,
+ prime_fd_to_handle: None,
+ gem_prime_import: None,
+ gem_prime_import_sg_table: None,
+ dumb_create: None,
+ dumb_map_offset: None,
+ };
+}
+
+pub(super) const fn create_fops() -> bindings::file_operations {
+ // SAFETY: As by the type invariant, it is safe to initialize `bindings::file_operations`
+ // zeroed.
+ let mut fops: bindings::file_operations = unsafe { core::mem::zeroed() };
+
+ fops.owner = core::ptr::null_mut();
+ fops.open = Some(bindings::drm_open);
+ fops.release = Some(bindings::drm_release);
+ fops.unlocked_ioctl = Some(bindings::drm_ioctl);
+ #[cfg(CONFIG_COMPAT)]
+ {
+ fops.compat_ioctl = Some(bindings::drm_compat_ioctl);
+ }
+ fops.poll = Some(bindings::drm_poll);
+ fops.read = Some(bindings::drm_read);
+ fops.llseek = Some(bindings::noop_llseek);
+ fops.mmap = Some(bindings::drm_gem_mmap);
+ fops.fop_flags = bindings::FOP_UNSIGNED_OFFSET;
+
+ fops
+}
diff --git a/rust/kernel/drm/ioctl.rs b/rust/kernel/drm/ioctl.rs
new file mode 100644
index 000000000000..445639404fb7
--- /dev/null
+++ b/rust/kernel/drm/ioctl.rs
@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+
+//! DRM IOCTL definitions.
+//!
+//! C header: [`include/linux/drm/drm_ioctl.h`](srctree/include/linux/drm/drm_ioctl.h)
+
+use crate::ioctl;
+
+const BASE: u32 = uapi::DRM_IOCTL_BASE as u32;
+
+/// Construct a DRM ioctl number with no argument.
+#[allow(non_snake_case)]
+#[inline(always)]
+pub const fn IO(nr: u32) -> u32 {
+ ioctl::_IO(BASE, nr)
+}
+
+/// Construct a DRM ioctl number with a read-only argument.
+#[allow(non_snake_case)]
+#[inline(always)]
+pub const fn IOR<T>(nr: u32) -> u32 {
+ ioctl::_IOR::<T>(BASE, nr)
+}
+
+/// Construct a DRM ioctl number with a write-only argument.
+#[allow(non_snake_case)]
+#[inline(always)]
+pub const fn IOW<T>(nr: u32) -> u32 {
+ ioctl::_IOW::<T>(BASE, nr)
+}
+
+/// Construct a DRM ioctl number with a read-write argument.
+#[allow(non_snake_case)]
+#[inline(always)]
+pub const fn IOWR<T>(nr: u32) -> u32 {
+ ioctl::_IOWR::<T>(BASE, nr)
+}
+
+/// Descriptor type for DRM ioctls. Use the `declare_drm_ioctls!{}` macro to construct them.
+pub type DrmIoctlDescriptor = bindings::drm_ioctl_desc;
+
+/// This is for ioctl which are used for rendering, and require that the file descriptor is either
+/// for a render node, or if it’s a legacy/primary node, then it must be authenticated.
+pub const AUTH: u32 = bindings::drm_ioctl_flags_DRM_AUTH;
+
+/// This must be set for any ioctl which can change the modeset or display state. Userspace must
+/// call the ioctl through a primary node, while it is the active master.
+///
+/// Note that read-only modeset ioctl can also be called by unauthenticated clients, or when a
+/// master is not the currently active one.
+pub const MASTER: u32 = bindings::drm_ioctl_flags_DRM_MASTER;
+
+/// Anything that could potentially wreak a master file descriptor needs to have this flag set.
+///
+/// Current that’s only for the SETMASTER and DROPMASTER ioctl, which e.g. logind can call to
+/// force a non-behaving master (display compositor) into compliance.
+///
+/// This is equivalent to callers with the SYSADMIN capability.
+pub const ROOT_ONLY: u32 = bindings::drm_ioctl_flags_DRM_ROOT_ONLY;
+
+/// This is used for all ioctl needed for rendering only, for drivers which support render nodes.
+/// This should be all new render drivers, and hence it should be always set for any ioctl with
+/// `AUTH` set. Note though that read-only query ioctl might have this set, but have not set
+/// DRM_AUTH because they do not require authentication.
+pub const RENDER_ALLOW: u32 = bindings::drm_ioctl_flags_DRM_RENDER_ALLOW;
+
+/// Internal structures used by the `declare_drm_ioctls!{}` macro. Do not use directly.
+#[doc(hidden)]
+pub mod internal {
+ pub use bindings::drm_device;
+ pub use bindings::drm_file;
+ pub use bindings::drm_ioctl_desc;
+}
+
+/// Declare the DRM ioctls for a driver.
+///
+/// Each entry in the list should have the form:
+///
+/// `(ioctl_number, argument_type, flags, user_callback),`
+///
+/// `argument_type` is the type name within the `bindings` crate.
+/// `user_callback` should have the following prototype:
+///
+/// ```ignore
+/// fn foo(device: &kernel::drm::Device<Self>,
+/// data: &Opaque<uapi::argument_type>,
+/// file: &kernel::drm::File<Self::File>,
+/// ) -> Result<u32>
+/// ```
+/// where `Self` is the drm::drv::Driver implementation these ioctls are being declared within.
+///
+/// # Examples
+///
+/// ```ignore
+/// kernel::declare_drm_ioctls! {
+/// (FOO_GET_PARAM, drm_foo_get_param, ioctl::RENDER_ALLOW, my_get_param_handler),
+/// }
+/// ```
+///
+#[macro_export]
+macro_rules! declare_drm_ioctls {
+ ( $(($cmd:ident, $struct:ident, $flags:expr, $func:expr)),* $(,)? ) => {
+ const IOCTLS: &'static [$crate::drm::ioctl::DrmIoctlDescriptor] = {
+ use $crate::uapi::*;
+ const _:() = {
+ let i: u32 = $crate::uapi::DRM_COMMAND_BASE;
+ // Assert that all the IOCTLs are in the right order and there are no gaps,
+ // and that the size of the specified type is correct.
+ $(
+ let cmd: u32 = $crate::macros::concat_idents!(DRM_IOCTL_, $cmd);
+ ::core::assert!(i == $crate::ioctl::_IOC_NR(cmd));
+ ::core::assert!(core::mem::size_of::<$crate::uapi::$struct>() ==
+ $crate::ioctl::_IOC_SIZE(cmd));
+ let i: u32 = i + 1;
+ )*
+ };
+
+ let ioctls = &[$(
+ $crate::drm::ioctl::internal::drm_ioctl_desc {
+ cmd: $crate::macros::concat_idents!(DRM_IOCTL_, $cmd) as u32,
+ func: {
+ #[allow(non_snake_case)]
+ unsafe extern "C" fn $cmd(
+ raw_dev: *mut $crate::drm::ioctl::internal::drm_device,
+ raw_data: *mut ::core::ffi::c_void,
+ raw_file: *mut $crate::drm::ioctl::internal::drm_file,
+ ) -> core::ffi::c_int {
+ // SAFETY:
+ // - The DRM core ensures the device lives while callbacks are being
+ // called.
+ // - The DRM device must have been registered when we're called through
+ // an IOCTL.
+ //
+ // FIXME: Currently there is nothing enforcing that the types of the
+ // dev/file match the current driver these ioctls are being declared
+ // for, and it's not clear how to enforce this within the type system.
+ let dev = $crate::drm::device::Device::as_ref(raw_dev);
+ // SAFETY: The ioctl argument has size `_IOC_SIZE(cmd)`, which we
+ // asserted above matches the size of this type, and all bit patterns of
+ // UAPI structs must be valid.
+ let data = unsafe {
+ &*(raw_data as *const $crate::types::Opaque<$crate::uapi::$struct>)
+ };
+ // SAFETY: This is just the DRM file structure
+ let file = unsafe { $crate::drm::File::as_ref(raw_file) };
+
+ match $func(dev, data, file) {
+ Err(e) => e.to_errno(),
+ Ok(i) => i.try_into()
+ .unwrap_or($crate::error::code::ERANGE.to_errno()),
+ }
+ }
+ Some($cmd)
+ },
+ flags: $flags,
+ name: $crate::c_str!(::core::stringify!($cmd)).as_char_ptr(),
+ }
+ ),*];
+ ioctls
+ };
+ };
+}
diff --git a/rust/kernel/drm/mod.rs b/rust/kernel/drm/mod.rs
new file mode 100644
index 000000000000..1b82b6945edf
--- /dev/null
+++ b/rust/kernel/drm/mod.rs
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0 OR MIT
+
+//! DRM subsystem abstractions.
+
+pub mod device;
+pub mod driver;
+pub mod file;
+pub mod gem;
+pub mod ioctl;
+
+pub use self::device::Device;
+pub use self::driver::Driver;
+pub use self::driver::DriverInfo;
+pub use self::driver::Registration;
+pub use self::file::File;
+
+pub(crate) mod private {
+ pub trait Sealed {}
+}
diff --git a/rust/kernel/lib.rs b/rust/kernel/lib.rs
index bcbf5026449d..1cf1bd5b73fc 100644
--- a/rust/kernel/lib.rs
+++ b/rust/kernel/lib.rs
@@ -38,6 +38,8 @@ extern crate self as kernel;
pub use ffi;
pub mod alloc;
+#[cfg(CONFIG_AUXILIARY_BUS)]
+pub mod auxiliary;
#[cfg(CONFIG_BLOCK)]
pub mod block;
#[doc(hidden)]
@@ -50,6 +52,8 @@ pub mod device_id;
pub mod devres;
pub mod dma;
pub mod driver;
+#[cfg(CONFIG_DRM = "y")]
+pub mod drm;
pub mod error;
pub mod faux;
#[cfg(CONFIG_RUST_FW_LOADER_ABSTRACTIONS)]
diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
index c97d6d470b28..38fc8d5ffbf9 100644
--- a/rust/kernel/pci.rs
+++ b/rust/kernel/pci.rs
@@ -6,7 +6,7 @@
use crate::{
alloc::flags::*,
- bindings, device,
+ bindings, container_of, device,
device_id::RawDeviceId,
devres::Devres,
driver,
@@ -360,11 +360,13 @@ impl<const SIZE: usize> Deref for Bar<SIZE> {
}
}
-impl Device {
+impl<Ctx: device::DeviceContext> Device<Ctx> {
fn as_raw(&self) -> *mut bindings::pci_dev {
self.0.get()
}
+}
+impl Device {
/// Returns the PCI vendor ID.
pub fn vendor_id(&self) -> u16 {
// SAFETY: `self.as_raw` is a valid pointer to a `struct pci_dev`.
@@ -388,7 +390,9 @@ impl Device {
// - by its type invariant `self.as_raw` is always a valid pointer to a `struct pci_dev`.
Ok(unsafe { bindings::pci_resource_len(self.as_raw(), bar.try_into()?) })
}
+}
+impl Device<device::Bound> {
/// Mapps an entire PCI-BAR after performing a region-request on it. I/O operation bound checks
/// can be performed on compile time for offsets (plus the requested type size) < SIZE.
pub fn iomap_region_sized<const SIZE: usize>(
@@ -422,25 +426,10 @@ impl Device<device::Core> {
}
}
-impl Deref for Device<device::Core> {
- type Target = Device;
-
- fn deref(&self) -> &Self::Target {
- let ptr: *const Self = self;
-
- // CAST: `Device<Ctx>` is a transparent wrapper of `Opaque<bindings::pci_dev>`.
- let ptr = ptr.cast::<Device>();
-
- // SAFETY: `ptr` was derived from `&self`.
- unsafe { &*ptr }
- }
-}
-
-impl From<&Device<device::Core>> for ARef<Device> {
- fn from(dev: &Device<device::Core>) -> Self {
- (&**dev).into()
- }
-}
+// SAFETY: `Device` is a transparent wrapper of a type that doesn't depend on `Device`'s generic
+// argument.
+kernel::impl_device_context_deref!(unsafe { Device });
+kernel::impl_device_context_into_aref!(Device);
// SAFETY: Instances of `Device` are always reference-counted.
unsafe impl crate::types::AlwaysRefCounted for Device {
@@ -455,8 +444,8 @@ unsafe impl crate::types::AlwaysRefCounted for Device {
}
}
-impl AsRef<device::Device> for Device {
- fn as_ref(&self) -> &device::Device {
+impl<Ctx: device::DeviceContext> AsRef<device::Device<Ctx>> for Device<Ctx> {
+ fn as_ref(&self) -> &device::Device<Ctx> {
// SAFETY: By the type invariant of `Self`, `self.as_raw()` is a pointer to a valid
// `struct pci_dev`.
let dev = unsafe { addr_of_mut!((*self.as_raw()).dev) };
@@ -466,6 +455,26 @@ impl AsRef<device::Device> for Device {
}
}
+impl<Ctx: device::DeviceContext> TryFrom<&device::Device<Ctx>> for &Device<Ctx> {
+ type Error = kernel::error::Error;
+
+ fn try_from(dev: &device::Device<Ctx>) -> Result<Self, Self::Error> {
+ // SAFETY: By the type invariant of `Device`, `dev.as_raw()` is a valid pointer to a
+ // `struct device`.
+ if !unsafe { bindings::dev_is_pci(dev.as_raw()) } {
+ return Err(EINVAL);
+ }
+
+ // SAFETY: We've just verified that the bus type of `dev` equals `bindings::pci_bus_type`,
+ // hence `dev` must be embedded in a valid `struct pci_dev` as guaranteed by the
+ // corresponding C code.
+ let pdev = unsafe { container_of!(dev.as_raw(), bindings::pci_dev, dev) };
+
+ // SAFETY: `pdev` is a valid pointer to a `struct pci_dev`.
+ Ok(unsafe { &*pdev.cast() })
+ }
+}
+
// SAFETY: A `Device` is always reference-counted and can be released from any thread.
unsafe impl Send for Device {}
diff --git a/rust/kernel/platform.rs b/rust/kernel/platform.rs
index 4917cb34e2fe..08849d92c074 100644
--- a/rust/kernel/platform.rs
+++ b/rust/kernel/platform.rs
@@ -5,18 +5,17 @@
//! C header: [`include/linux/platform_device.h`](srctree/include/linux/platform_device.h)
use crate::{
- bindings, device, driver,
+ bindings, container_of, device, driver,
error::{to_result, Result},
of,
prelude::*,
str::CStr,
- types::{ARef, ForeignOwnable, Opaque},
+ types::{ForeignOwnable, Opaque},
ThisModule,
};
use core::{
marker::PhantomData,
- ops::Deref,
ptr::{addr_of_mut, NonNull},
};
@@ -184,31 +183,16 @@ pub struct Device<Ctx: device::DeviceContext = device::Normal>(
PhantomData<Ctx>,
);
-impl Device {
+impl<Ctx: device::DeviceContext> Device<Ctx> {
fn as_raw(&self) -> *mut bindings::platform_device {
self.0.get()
}
}
-impl Deref for Device<device::Core> {
- type Target = Device;
-
- fn deref(&self) -> &Self::Target {
- let ptr: *const Self = self;
-
- // CAST: `Device<Ctx>` is a transparent wrapper of `Opaque<bindings::platform_device>`.
- let ptr = ptr.cast::<Device>();
-
- // SAFETY: `ptr` was derived from `&self`.
- unsafe { &*ptr }
- }
-}
-
-impl From<&Device<device::Core>> for ARef<Device> {
- fn from(dev: &Device<device::Core>) -> Self {
- (&**dev).into()
- }
-}
+// SAFETY: `Device` is a transparent wrapper of a type that doesn't depend on `Device`'s generic
+// argument.
+kernel::impl_device_context_deref!(unsafe { Device });
+kernel::impl_device_context_into_aref!(Device);
// SAFETY: Instances of `Device` are always reference-counted.
unsafe impl crate::types::AlwaysRefCounted for Device {
@@ -223,8 +207,8 @@ unsafe impl crate::types::AlwaysRefCounted for Device {
}
}
-impl AsRef<device::Device> for Device {
- fn as_ref(&self) -> &device::Device {
+impl<Ctx: device::DeviceContext> AsRef<device::Device<Ctx>> for Device<Ctx> {
+ fn as_ref(&self) -> &device::Device<Ctx> {
// SAFETY: By the type invariant of `Self`, `self.as_raw()` is a pointer to a valid
// `struct platform_device`.
let dev = unsafe { addr_of_mut!((*self.as_raw()).dev) };
@@ -234,6 +218,26 @@ impl AsRef<device::Device> for Device {
}
}
+impl<Ctx: device::DeviceContext> TryFrom<&device::Device<Ctx>> for &Device<Ctx> {
+ type Error = kernel::error::Error;
+
+ fn try_from(dev: &device::Device<Ctx>) -> Result<Self, Self::Error> {
+ // SAFETY: By the type invariant of `Device`, `dev.as_raw()` is a valid pointer to a
+ // `struct device`.
+ if !unsafe { bindings::dev_is_platform(dev.as_raw()) } {
+ return Err(EINVAL);
+ }
+
+ // SAFETY: We've just verified that the bus type of `dev` equals
+ // `bindings::platform_bus_type`, hence `dev` must be embedded in a valid
+ // `struct platform_device` as guaranteed by the corresponding C code.
+ let pdev = unsafe { container_of!(dev.as_raw(), bindings::platform_device, dev) };
+
+ // SAFETY: `pdev` is a valid pointer to a `struct platform_device`.
+ Ok(unsafe { &*pdev.cast() })
+ }
+}
+
// SAFETY: A `Device` is always reference-counted and can be released from any thread.
unsafe impl Send for Device {}
diff --git a/rust/kernel/revocable.rs b/rust/kernel/revocable.rs
index 1e5a9d25c21b..db4aa46bb121 100644
--- a/rust/kernel/revocable.rs
+++ b/rust/kernel/revocable.rs
@@ -123,6 +123,34 @@ impl<T> Revocable<T> {
}
}
+ /// Tries to access the wrapped object and run a closure on it while the guard is held.
+ ///
+ /// This is a convenience method to run short non-sleepable code blocks while ensuring the
+ /// guard is dropped afterwards. [`Self::try_access`] carries the risk that the caller will
+ /// forget to explicitly drop that returned guard before calling sleepable code; this method
+ /// adds an extra safety to make sure it doesn't happen.
+ ///
+ /// Returns [`None`] if the object has been revoked and is therefore no longer accessible, or
+ /// the result of the closure wrapped in [`Some`]. If the closure returns a [`Result`] then the
+ /// return type becomes `Option<Result<>>`, which can be inconvenient. Users are encouraged to
+ /// define their own macro that turns the [`Option`] into a proper error code and flattens the
+ /// inner result into it if it makes sense within their subsystem.
+ pub fn try_access_with<R, F: FnOnce(&T) -> R>(&self, f: F) -> Option<R> {
+ self.try_access().map(|t| f(&*t))
+ }
+
+ /// Directly access the revocable wrapped object.
+ ///
+ /// # Safety
+ ///
+ /// The caller must ensure this [`Revocable`] instance hasn't been revoked and won't be revoked
+ /// as long as the returned `&T` lives.
+ pub unsafe fn access(&self) -> &T {
+ // SAFETY: By the safety requirement of this function it is guaranteed that
+ // `self.data.get()` is a valid pointer to an instance of `T`.
+ unsafe { &*self.data.get() }
+ }
+
/// # Safety
///
/// Callers must ensure that there are no more concurrent users of the revocable object.
diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
index 9d0471afc964..eee387727d1a 100644
--- a/rust/kernel/types.rs
+++ b/rust/kernel/types.rs
@@ -329,6 +329,14 @@ impl<T> Opaque<T> {
}
}
+ /// 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| {