1 // SPDX-License-Identifier: GPL-2.0 OR MIT 2 3 //! DRM driver core. 4 //! 5 //! C header: [`include/drm/drm_drv.h`](srctree/include/drm/drm_drv.h) 6 7 use crate::{ 8 bindings, 9 device, 10 devres, 11 drm, 12 error::to_result, 13 prelude::*, 14 sync::aref::ARef, // 15 }; 16 17 /// Driver use the GEM memory manager. This should be set for all modern drivers. 18 pub(crate) const FEAT_GEM: u32 = bindings::drm_driver_feature_DRIVER_GEM; 19 20 /// Information data for a DRM Driver. 21 pub struct DriverInfo { 22 /// Driver major version. 23 pub major: i32, 24 /// Driver minor version. 25 pub minor: i32, 26 /// Driver patchlevel version. 27 pub patchlevel: i32, 28 /// Driver name. 29 pub name: &'static CStr, 30 /// Driver description. 31 pub desc: &'static CStr, 32 } 33 34 /// Internal memory management operation set, normally created by memory managers (e.g. GEM). 35 pub struct AllocOps { 36 pub(crate) gem_create_object: Option< 37 unsafe extern "C" fn( 38 dev: *mut bindings::drm_device, 39 size: usize, 40 ) -> *mut bindings::drm_gem_object, 41 >, 42 pub(crate) prime_handle_to_fd: Option< 43 unsafe extern "C" fn( 44 dev: *mut bindings::drm_device, 45 file_priv: *mut bindings::drm_file, 46 handle: u32, 47 flags: u32, 48 prime_fd: *mut core::ffi::c_int, 49 ) -> core::ffi::c_int, 50 >, 51 pub(crate) prime_fd_to_handle: Option< 52 unsafe extern "C" fn( 53 dev: *mut bindings::drm_device, 54 file_priv: *mut bindings::drm_file, 55 prime_fd: core::ffi::c_int, 56 handle: *mut u32, 57 ) -> core::ffi::c_int, 58 >, 59 pub(crate) gem_prime_import: Option< 60 unsafe extern "C" fn( 61 dev: *mut bindings::drm_device, 62 dma_buf: *mut bindings::dma_buf, 63 ) -> *mut bindings::drm_gem_object, 64 >, 65 pub(crate) gem_prime_import_sg_table: Option< 66 unsafe extern "C" fn( 67 dev: *mut bindings::drm_device, 68 attach: *mut bindings::dma_buf_attachment, 69 sgt: *mut bindings::sg_table, 70 ) -> *mut bindings::drm_gem_object, 71 >, 72 pub(crate) dumb_create: Option< 73 unsafe extern "C" fn( 74 file_priv: *mut bindings::drm_file, 75 dev: *mut bindings::drm_device, 76 args: *mut bindings::drm_mode_create_dumb, 77 ) -> core::ffi::c_int, 78 >, 79 pub(crate) dumb_map_offset: Option< 80 unsafe extern "C" fn( 81 file_priv: *mut bindings::drm_file, 82 dev: *mut bindings::drm_device, 83 handle: u32, 84 offset: *mut u64, 85 ) -> core::ffi::c_int, 86 >, 87 } 88 89 /// Trait for memory manager implementations. Implemented internally. 90 pub trait AllocImpl: super::private::Sealed + drm::gem::IntoGEMObject { 91 /// The [`Driver`] implementation for this [`AllocImpl`]. 92 type Driver: drm::Driver; 93 94 /// The C callback operations for this memory manager. 95 const ALLOC_OPS: AllocOps; 96 } 97 98 /// The DRM `Driver` trait. 99 /// 100 /// This trait must be implemented by drivers in order to create a `struct drm_device` and `struct 101 /// drm_driver` to be registered in the DRM subsystem. 102 #[vtable] 103 pub trait Driver { 104 /// Context data associated with the DRM driver 105 type Data: Sync + Send; 106 107 /// The type used to manage memory for this driver. 108 type Object: AllocImpl; 109 110 /// The type used to represent a DRM File (client) 111 type File: drm::file::DriverFile; 112 113 /// Driver metadata 114 const INFO: DriverInfo; 115 116 /// IOCTL list. See `kernel::drm::ioctl::declare_drm_ioctls!{}`. 117 const IOCTLS: &'static [drm::ioctl::DrmIoctlDescriptor]; 118 } 119 120 /// The registration type of a `drm::Device`. 121 /// 122 /// Once the `Registration` structure is dropped, the device is unregistered. 123 pub struct Registration<T: Driver>(ARef<drm::Device<T>>); 124 125 impl<T: Driver> Registration<T> { 126 fn new(drm: &drm::Device<T>, flags: usize) -> Result<Self> { 127 // SAFETY: `drm.as_raw()` is valid by the invariants of `drm::Device`. 128 to_result(unsafe { bindings::drm_dev_register(drm.as_raw(), flags) })?; 129 130 Ok(Self(drm.into())) 131 } 132 133 /// Registers a new [`Device`](drm::Device) with userspace. 134 /// 135 /// Ownership of the [`Registration`] object is passed to [`devres::register`]. 136 pub fn new_foreign_owned( 137 drm: &drm::Device<T>, 138 dev: &device::Device<device::Bound>, 139 flags: usize, 140 ) -> Result 141 where 142 T: 'static, 143 { 144 if drm.as_ref().as_raw() != dev.as_raw() { 145 return Err(EINVAL); 146 } 147 148 let reg = Registration::<T>::new(drm, flags)?; 149 150 devres::register(dev, reg, GFP_KERNEL) 151 } 152 153 /// Returns a reference to the `Device` instance for this registration. 154 pub fn device(&self) -> &drm::Device<T> { 155 &self.0 156 } 157 } 158 159 // SAFETY: `Registration` doesn't offer any methods or access to fields when shared between 160 // threads, hence it's safe to share it. 161 unsafe impl<T: Driver> Sync for Registration<T> {} 162 163 // SAFETY: Registration with and unregistration from the DRM subsystem can happen from any thread. 164 unsafe impl<T: Driver> Send for Registration<T> {} 165 166 impl<T: Driver> Drop for Registration<T> { 167 fn drop(&mut self) { 168 // SAFETY: Safe by the invariant of `ARef<drm::Device<T>>`. The existence of this 169 // `Registration` also guarantees the this `drm::Device` is actually registered. 170 unsafe { bindings::drm_dev_unregister(self.0.as_raw()) }; 171 } 172 } 173