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authorAlice Ryhl <aliceryhl@google.com>2026-04-09 15:26:08 +0000
committerDanilo Krummrich <dakr@kernel.org>2026-05-05 12:52:49 +0200
commit5540a9c747b3e1914ae68ae89f71c0a779bee5d1 (patch)
tree544236d67729a4abe99922c7918e903c09c578f7 /rust
parent71a3921111bd05298988fad1c58241db13384ea7 (diff)
downloadath-5540a9c747b3e1914ae68ae89f71c0a779bee5d1.tar.gz
rust: gpuvm: add GpuVa struct
This struct will be used to keep track of individual mapped ranges in the GPU's virtual memory. Sparse VAs are not yet supported. Co-developed-by: Asahi Lina <lina+kernel@asahilina.net> Signed-off-by: Asahi Lina <lina+kernel@asahilina.net> Co-developed-by: Daniel Almeida <daniel.almeida@collabora.com> Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com> Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://patch.msgid.link/20260409-gpuvm-rust-v6-3-b16e6ada7261@google.com Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Diffstat (limited to 'rust')
-rw-r--r--rust/kernel/drm/gpuvm/mod.rs19
-rw-r--r--rust/kernel/drm/gpuvm/va.rs169
-rw-r--r--rust/kernel/drm/gpuvm/vm_bo.rs1
3 files changed, 185 insertions, 4 deletions
diff --git a/rust/kernel/drm/gpuvm/mod.rs b/rust/kernel/drm/gpuvm/mod.rs
index 56e02b49a5812..78951e8aa5d3a 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 kernel::{
use core::{
cell::UnsafeCell,
- mem::ManuallyDrop,
+ mem::{
+ ManuallyDrop,
+ MaybeUninit, //
+ },
ops::{
Deref,
+ DerefMut,
Range, //
},
ptr::{
@@ -36,6 +43,9 @@ use core::{
}, //
};
+mod va;
+pub use self::va::*;
+
mod vm_bo;
pub use self::vm_bo::*;
@@ -48,7 +58,7 @@ pub use self::vm_bo::*;
///
/// * Stored in an allocation managed by the refcount in `self.vm`.
/// * Access to `data` and the gpuvm interval tree is controlled via the [`UniqueRefGpuVm`] type.
-/// * Does not contain any sparse `GpuVa` instances.
+/// * Does not contain any sparse [`GpuVa<T>`] instances.
#[pin_data]
pub struct GpuVm<T: DriverGpuVm> {
#[pin]
@@ -242,6 +252,9 @@ pub trait DriverGpuVm: Sized + Send {
/// The kind of GEM object stored in this GPUVM.
type Object: IntoGEMObject;
+ /// Data stored with each [`struct drm_gpuva`](struct@GpuVa).
+ type VaData;
+
/// Data stored with each [`struct drm_gpuvm_bo`](struct@GpuVmBo).
type VmBoData;
}
diff --git a/rust/kernel/drm/gpuvm/va.rs b/rust/kernel/drm/gpuvm/va.rs
new file mode 100644
index 0000000000000..227c259f7db95
--- /dev/null
+++ b/rust/kernel/drm/gpuvm/va.rs
@@ -0,0 +1,169 @@
+// 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` object that is resident in a [`GpuVm<T>`] instance.
+/// * It is associated with a [`GpuVmBo<T>`]. Or in other words, it's not an
+/// `gpuvm->kernel_alloc_node` and `DRM_GPUVA_SPARSE` is not set.
+/// * The associated [`GpuVmBo<T>`] is part of the GEM list.
+#[repr(C)]
+#[pin_data]
+pub struct GpuVa<T: DriverGpuVm> {
+ #[pin]
+ inner: Opaque<bindings::drm_gpuva>,
+ #[pin]
+ data: T::VaData,
+}
+
+impl<T: DriverGpuVm> PartialEq for GpuVa<T> {
+ #[inline]
+ fn eq(&self, other: &Self) -> bool {
+ core::ptr::eq(self.as_raw(), other.as_raw())
+ }
+}
+impl<T: DriverGpuVm> Eq for GpuVa<T> {}
+
+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>`].
+ /// * It must be associated with a [`GpuVmBo<T>`].
+ /// * The associated [`GpuVmBo<T>`] is part of the GEM list.
+ #[inline]
+ pub unsafe fn from_raw<'a>(ptr: *mut bindings::drm_gpuva) -> &'a Self {
+ // CAST: `drm_gpuva` is first field and `repr(C)`.
+ // SAFETY: The safety requirements match the invariants of `GpuVa`.
+ 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.obj` field of `drm_gpuva` is immutable. We know that it's not null
+ // because this VA is associated with a `GpuVmBo<T>`.
+ 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 of `drm_gpuva` is immutable. We know that it's not null
+ // because this VA is associated with a `GpuVmBo<T>`. The BO is in the GEM list by the type
+ // invariants.
+ 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.
+ #[must_use]
+ 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>`].
+ /// * It must not be a `gpuvm->kernel_alloc_node` va.
+ pub(super) unsafe fn from_raw(ptr: *mut bindings::drm_gpuva) -> Self {
+ // SAFETY: Since it used to be a VA in a `GpuVm<T>` and it's not a kernel_alloc_node, this
+ // pointer references a `GpuVa<T>` with a valid `T::VaData`. Since it has been removed, we
+ // can take ownership of the 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
+ }
+}
diff --git a/rust/kernel/drm/gpuvm/vm_bo.rs b/rust/kernel/drm/gpuvm/vm_bo.rs
index 65f03f93bd21a..05fd7998f4bdb 100644
--- a/rust/kernel/drm/gpuvm/vm_bo.rs
+++ b/rust/kernel/drm/gpuvm/vm_bo.rs
@@ -114,7 +114,6 @@ impl<T: DriverGpuVm> GpuVmBo<T> {
/// For the duration of `'a`, the pointer must reference a valid `drm_gpuvm_bo` associated with
/// a [`GpuVm<T>`]. The BO must also be present in the GEM list.
#[inline]
- #[expect(dead_code)]
pub(crate) unsafe fn from_raw<'a>(ptr: *mut bindings::drm_gpuvm_bo) -> &'a Self {
// SAFETY: `drm_gpuvm_bo` is first field and `repr(C)`.
unsafe { &*ptr.cast() }
generated by cgit 1.3-korg (git 2.53.0) at 2026-07-01 13:25:26 +0000