// SPDX-License-Identifier: GPL-2.0 OR MIT //! DRM driver core. //! //! C header: [`include/drm/drm_drv.h`](srctree/include/drm/drm_drv.h) use crate::{ bindings, device, devres, drm, error::to_result, prelude::*, sync::aref::ARef, // }; use core::{ mem, ptr::NonNull, // }; /// 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; /// Driver supports render nodes, i.e.: /dev/dri/renderDXX devices. pub(crate) const FEAT_RENDER: u32 = bindings::drm_driver_feature_DRIVER_RENDER; /// 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 [`Driver`] implementation for this [`AllocImpl`]. type Driver: drm::Driver; /// 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]; /// Sets the `DRIVER_RENDER` feature for this driver. /// /// When enabled, the driver exposes `/dev/dri/renderDXX` render nodes to /// userspace. The render node is an alternate low-priviledge way to access /// the driver, which is enforced on a per-ioctl level. Userspace processes /// that open the render node can only invoke ioctls explicitly listed as /// usable from the render node (i.e. marked DRM_RENDER_ALLOW), whereas /// userspace processes using the master node can invoke any ioctl. const FEAT_RENDER: bool = false; } /// The registration type of a `drm::Device`. /// /// Once the `Registration` structure is dropped, the device is unregistered. pub struct Registration(ARef>); impl Registration { fn new(drm: drm::UnregisteredDevice, flags: usize) -> Result { // SAFETY: `drm.as_raw()` is valid by the invariants of `drm::Device`. to_result(unsafe { bindings::drm_dev_register(drm.as_raw(), flags) })?; // SAFETY: We just called `drm_dev_register` above let new = NonNull::from(unsafe { drm.assume_ctx() }); // Leak the ARef from UnregisteredDevice in preparation for transferring its ownership. mem::forget(drm); // SAFETY: `drm`'s `Drop` constructor was never called, ensuring that there remains at least // one reference to the device - which we take ownership over here. let new = unsafe { ARef::from_raw(new) }; Ok(Self(new)) } /// Registers a new [`UnregisteredDevice`](drm::UnregisteredDevice) with userspace. /// /// Ownership of the [`Registration`] object is passed to [`devres::register`]. pub fn new_foreign_owned<'a>( drm: drm::UnregisteredDevice, dev: &'a device::Device, flags: usize, ) -> Result<&'a drm::Device> where T: 'static, { if drm.as_ref().as_raw() != dev.as_raw() { return Err(EINVAL); } let reg = Registration::::new(drm, flags)?; let drm = NonNull::from(reg.device()); devres::register(dev, reg, GFP_KERNEL)?; // SAFETY: Since `reg` was passed to devres::register(), the device now owns the lifetime // of the DRM registration - ensuring that this references lives for at least as long as 'a. Ok(unsafe { drm.as_ref() }) } /// Returns a reference to the `Device` instance for this registration. pub fn device(&self) -> &drm::Device { &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 Sync for Registration {} // SAFETY: Registration with and unregistration from the DRM subsystem can happen from any thread. unsafe impl Send for Registration {} impl Drop for Registration { fn drop(&mut self) { // SAFETY: Safe by the invariant of `ARef>`. The existence of this // `Registration` also guarantees the this `drm::Device` is actually registered. unsafe { bindings::drm_dev_unregister(self.0.as_raw()) }; } }