This struct will be used to keep track of individual mapped ranges in the GPU's virtual memory.
Co-developed-by: Asahi Lina <[email protected]> Signed-off-by: Asahi Lina <[email protected]> Co-developed-by: Daniel Almeida <[email protected]> Signed-off-by: Daniel Almeida <[email protected]> Signed-off-by: Alice Ryhl <[email protected]> --- rust/kernel/drm/gpuvm/mod.rs | 17 ++++- rust/kernel/drm/gpuvm/va.rs | 149 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 164 insertions(+), 2 deletions(-) diff --git a/rust/kernel/drm/gpuvm/mod.rs b/rust/kernel/drm/gpuvm/mod.rs index cb576a7ffa07bc108704e008b7f87de52a837930..2179ddd717d8728bbe231bd94ea7b5d1e2652543 100644 --- a/rust/kernel/drm/gpuvm/mod.rs +++ b/rust/kernel/drm/gpuvm/mod.rs @@ -11,7 +11,10 @@ //! C header: [`include/drm/drm_gpuvm.h`](srctree/include/drm/drm_gpuvm.h) use kernel::{ - alloc::AllocError, + alloc::{ + AllocError, + Flags as AllocFlags, // + }, bindings, drm, drm::gem::IntoGEMObject, @@ -25,9 +28,13 @@ use core::{ cell::UnsafeCell, - mem::ManuallyDrop, + mem::{ + ManuallyDrop, + MaybeUninit, // + }, ops::{ Deref, + DerefMut, Range, // }, ptr::{ @@ -36,6 +43,9 @@ }, // }; +mod va; +pub use self::va::*; + mod vm_bo; pub use self::vm_bo::*; @@ -224,6 +234,9 @@ pub trait DriverGpuVm: Sized { /// The kind of GEM object stored in this GPUVM. type Object: IntoGEMObject; + /// Data stored with each `struct drm_gpuva`. + type VaData; + /// Data stored with each `struct drm_gpuvm_bo`. type VmBoData; } diff --git a/rust/kernel/drm/gpuvm/va.rs b/rust/kernel/drm/gpuvm/va.rs new file mode 100644 index 0000000000000000000000000000000000000000..c96796a6b2c8c7c4b5475324562968ca0f07fd09 --- /dev/null +++ b/rust/kernel/drm/gpuvm/va.rs @@ -0,0 +1,149 @@ +// SPDX-License-Identifier: GPL-2.0 OR MIT + +#![expect(dead_code)] +use super::*; + +/// Represents that a range of a GEM object is mapped in this [`GpuVm`] instance. +/// +/// Does not assume that GEM lock is held. +/// +/// # Invariants +/// +/// This is a valid `drm_gpuva` that is resident in the [`GpuVm`] instance. +#[repr(C)] +#[pin_data] +pub struct GpuVa<T: DriverGpuVm> { + #[pin] + inner: Opaque<bindings::drm_gpuva>, + #[pin] + data: T::VaData, +} + +impl<T: DriverGpuVm> GpuVa<T> { + /// Access this [`GpuVa`] from a raw pointer. + /// + /// # Safety + /// + /// For the duration of `'a`, the pointer must reference a valid `drm_gpuva` associated with a + /// [`GpuVm<T>`]. + #[inline] + pub unsafe fn from_raw<'a>(ptr: *mut bindings::drm_gpuva) -> &'a Self { + // SAFETY: `drm_gpuva` is first field and `repr(C)`. + unsafe { &*ptr.cast() } + } + + /// Returns a raw pointer to underlying C value. + #[inline] + pub fn as_raw(&self) -> *mut bindings::drm_gpuva { + self.inner.get() + } + + /// Returns the address of this mapping in the GPU virtual address space. + #[inline] + pub fn addr(&self) -> u64 { + // SAFETY: The `va.addr` field of `drm_gpuva` is immutable. + unsafe { (*self.as_raw()).va.addr } + } + + /// Returns the length of this mapping. + #[inline] + pub fn length(&self) -> u64 { + // SAFETY: The `va.range` field of `drm_gpuva` is immutable. + unsafe { (*self.as_raw()).va.range } + } + + /// Returns `addr..addr+length`. + #[inline] + pub fn range(&self) -> Range<u64> { + let addr = self.addr(); + addr..addr + self.length() + } + + /// Returns the offset within the GEM object. + #[inline] + pub fn gem_offset(&self) -> u64 { + // SAFETY: The `gem.offset` field of `drm_gpuva` is immutable. + unsafe { (*self.as_raw()).gem.offset } + } + + /// Returns the GEM object. + #[inline] + pub fn obj(&self) -> &T::Object { + // SAFETY: The `gem.offset` field of `drm_gpuva` is immutable. + unsafe { <T::Object as IntoGEMObject>::from_raw((*self.as_raw()).gem.obj) } + } + + /// Returns the underlying [`GpuVmBo`] object that backs this [`GpuVa`]. + #[inline] + pub fn vm_bo(&self) -> &GpuVmBo<T> { + // SAFETY: The `vm_bo` field has been set and is immutable for the duration in which this + // `drm_gpuva` is resident in the VM. + unsafe { GpuVmBo::from_raw((*self.as_raw()).vm_bo) } + } +} + +/// A pre-allocated [`GpuVa`] object. +/// +/// # Invariants +/// +/// The memory is zeroed. +pub struct GpuVaAlloc<T: DriverGpuVm>(KBox<MaybeUninit<GpuVa<T>>>); + +impl<T: DriverGpuVm> GpuVaAlloc<T> { + /// Pre-allocate a [`GpuVa`] object. + pub fn new(flags: AllocFlags) -> Result<GpuVaAlloc<T>, AllocError> { + // INVARIANTS: Memory allocated with __GFP_ZERO. + Ok(GpuVaAlloc(KBox::new_uninit(flags | __GFP_ZERO)?)) + } + + /// Prepare this `drm_gpuva` for insertion into the GPUVM. + pub(super) fn prepare(mut self, va_data: impl PinInit<T::VaData>) -> *mut bindings::drm_gpuva { + let va_ptr = MaybeUninit::as_mut_ptr(&mut self.0); + // SAFETY: The `data` field is pinned. + let Ok(()) = unsafe { va_data.__pinned_init(&raw mut (*va_ptr).data) }; + KBox::into_raw(self.0).cast() + } +} + +/// A [`GpuVa`] object that has been removed. +/// +/// # Invariants +/// +/// The `drm_gpuva` is not resident in the [`GpuVm`]. +pub struct GpuVaRemoved<T: DriverGpuVm>(KBox<GpuVa<T>>); + +impl<T: DriverGpuVm> GpuVaRemoved<T> { + /// Convert a raw pointer into a [`GpuVaRemoved`]. + /// + /// # Safety + /// + /// Must have been removed from a [`GpuVm<T>`]. + pub(super) unsafe fn from_raw(ptr: *mut bindings::drm_gpuva) -> Self { + // SAFETY: Since it has been removed we can take ownership of allocation. + GpuVaRemoved(unsafe { KBox::from_raw(ptr.cast()) }) + } + + /// Take ownership of the VA data. + pub fn into_inner(self) -> T::VaData + where + T::VaData: Unpin, + { + KBox::into_inner(self.0).data + } +} + +impl<T: DriverGpuVm> Deref for GpuVaRemoved<T> { + type Target = T::VaData; + fn deref(&self) -> &T::VaData { + &self.0.data + } +} + +impl<T: DriverGpuVm> DerefMut for GpuVaRemoved<T> +where + T::VaData: Unpin, +{ + fn deref_mut(&mut self) -> &mut T::VaData { + &mut self.0.data + } +} -- 2.52.0.457.g6b5491de43-goog
