Commit 07c90160 authored by Asahi Lina's avatar Asahi Lina Committed by Danilo Krummrich
Browse files

rust: drm: add driver abstractions 



Implement the DRM driver abstractions.

The `Driver` trait provides the interface to the actual driver to fill
in the driver specific data, such as the `DriverInfo`, driver features
and IOCTLs.

Reviewed-by: default avatarMaxime Ripard <mripard@kernel.org>
Signed-off-by: default avatarAsahi Lina <lina@asahilina.net>
Reviewed-by: default avatarAlyssa Rosenzweig <alyssa@rosenzweig.io>
Reviewed-by: default avatarLyude Paul <lyude@redhat.com>
Link: https://lore.kernel.org/r/20250410235546.43736-4-dakr@kernel.org
[ MISC changes
    * remove unnecessary DRM features; make remaining ones crate private
    * add #[expect(unused)] to avoid warnings
    * add sealed trait
    * remove shmem::Object references
    * original source archive: https://archive.is/Pl9ys



  - Danilo ]
Signed-off-by: default avatarDanilo Krummrich <dakr@kernel.org>
parent 9a695706

rust/bindings/bindings_helper.h

+1 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
 * Sorted alphabetically.

 */



#include <drm/drm_drv.h>

#include <drm/drm_ioctl.h>

#include <kunit/test.h>

#include <linux/auxiliary_bus.h>

rust/kernel/drm/driver.rs

0 → 100644
+113 −0
Original line number Diff line number Diff line 
// 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, drm, str::CStr};

use macros::vtable;



/// Driver use the GEM memory manager. This should be set for all modern drivers.

#[expect(unused)]

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 {

    #[expect(unused)]

    pub(crate) gem_create_object: Option<

        unsafe extern "C" fn(

            dev: *mut bindings::drm_device,

            size: usize,

        ) -> *mut bindings::drm_gem_object,

    >,

    #[expect(unused)]

    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,

    >,

    #[expect(unused)]

    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,

    >,

    #[expect(unused)]

    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,

    >,

    #[expect(unused)]

    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,

    >,

    #[expect(unused)]

    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,

    >,

    #[expect(unused)]

    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 {

    /// 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;



    /// Driver metadata

    const INFO: DriverInfo;



    /// IOCTL list. See `kernel::drm::ioctl::declare_drm_ioctls!{}`.

    const IOCTLS: &'static [drm::ioctl::DrmIoctlDescriptor];

}

rust/kernel/drm/mod.rs

+8 −0
Original line number Diff line number Diff line
@@ -2,4 +2,12 @@ 


//! DRM subsystem abstractions.



pub mod driver;

pub mod ioctl;



pub use self::driver::Driver;

pub use self::driver::DriverInfo;



pub(crate) mod private {

    pub trait Sealed {}

}