From: Alice Ryhl Date: Thu, 9 Apr 2026 15:26:10 +0000 (+0000) Subject: rust: gpuvm: add GpuVmCore::sm_map() X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=0b715b1e382b3d2e15d71c03a23be5f4333e7894;p=thirdparty%2Fkernel%2Flinux.git rust: gpuvm: add GpuVmCore::sm_map() Finally also add the operation for creating new mappings. Mapping operations need extra data in the context since they involve a vm_bo coming from the outside. Co-developed-by: Asahi Lina Signed-off-by: Asahi Lina Reviewed-by: Daniel Almeida Signed-off-by: Alice Ryhl Link: https://patch.msgid.link/20260409-gpuvm-rust-v6-5-b16e6ada7261@google.com Signed-off-by: Danilo Krummrich --- diff --git a/rust/kernel/drm/gpuvm/mod.rs b/rust/kernel/drm/gpuvm/mod.rs index a6436abd0f9c1..dc755f2481437 100644 --- a/rust/kernel/drm/gpuvm/mod.rs +++ b/rust/kernel/drm/gpuvm/mod.rs @@ -108,7 +108,7 @@ impl GpuVm { vm_bo_alloc: GpuVmBo::::ALLOC_FN, vm_bo_free: GpuVmBo::::FREE_FN, vm_bo_validate: None, - sm_step_map: None, + sm_step_map: Some(Self::sm_step_map), sm_step_unmap: Some(Self::sm_step_unmap), sm_step_remap: Some(Self::sm_step_remap), } @@ -266,6 +266,13 @@ pub trait DriverGpuVm: Sized + Send { /// The private data passed to callbacks. type SmContext<'ctx>; + /// Indicates that a new mapping should be created. + fn sm_step_map<'op, 'ctx>( + &mut self, + op: OpMap<'op, Self>, + context: &mut Self::SmContext<'ctx>, + ) -> Result, Error>; + /// Indicates that an existing mapping should be removed. fn sm_step_unmap<'op, 'ctx>( &mut self, diff --git a/rust/kernel/drm/gpuvm/sm_ops.rs b/rust/kernel/drm/gpuvm/sm_ops.rs index 05f81c638aefd..69a8e5ab2821f 100644 --- a/rust/kernel/drm/gpuvm/sm_ops.rs +++ b/rust/kernel/drm/gpuvm/sm_ops.rs @@ -8,6 +8,108 @@ struct SmData<'a, 'ctx, T: DriverGpuVm> { user_context: &'a mut T::SmContext<'ctx>, } +/// Adds an extra field to `SmData` for `sm_map()` callbacks. +/// +/// # Invariants +/// +/// `self.vm_bo.gpuvm() == self.sm_data.gpuvm`. +#[repr(C)] +struct SmMapData<'a, 'ctx, T: DriverGpuVm> { + sm_data: SmData<'a, 'ctx, T>, + vm_bo: &'a GpuVmBo, +} + +/// The argument for [`UniqueRefGpuVm::sm_map`]. +pub struct OpMapRequest<'a, 'ctx, T: DriverGpuVm> { + /// Address in GPU virtual address space. + pub addr: u64, + /// Length of mapping to create. + pub range: u64, + /// Offset in GEM object. + pub gem_offset: u64, + /// The GEM object to map. + pub vm_bo: &'a GpuVmBo, + /// The user-provided context type. + pub context: &'a mut T::SmContext<'ctx>, +} + +impl<'a, 'ctx, T: DriverGpuVm> OpMapRequest<'a, 'ctx, T> { + fn raw_request(&self) -> bindings::drm_gpuvm_map_req { + bindings::drm_gpuvm_map_req { + map: bindings::drm_gpuva_op_map { + va: bindings::drm_gpuva_op_map__bindgen_ty_1 { + addr: self.addr, + range: self.range, + }, + gem: bindings::drm_gpuva_op_map__bindgen_ty_2 { + offset: self.gem_offset, + obj: self.vm_bo.obj().as_raw(), + }, + }, + } + } +} + +/// Represents an `sm_step_map` operation that has not yet been completed. +pub struct OpMap<'op, T: DriverGpuVm> { + op: &'op bindings::drm_gpuva_op_map, + // Since these abstractions are designed for immediate mode, the VM BO needs to be + // pre-allocated, so we always have it available when we reach this point. + vm_bo: &'op GpuVmBo, + // This ensures that 'op is invariant, so that `OpMap<'long, T>` does not + // coerce to `OpMap<'short, T>`. This ensures that the user can't return + // the wrong `OpMapped` value. + _invariant: PhantomData<*mut &'op mut T>, +} + +impl<'op, T: DriverGpuVm> OpMap<'op, T> { + /// The base address of the new mapping. + pub fn addr(&self) -> u64 { + self.op.va.addr + } + + /// The length of the new mapping. + pub fn length(&self) -> u64 { + self.op.va.range + } + + /// The offset within the [`drm_gem_object`](DriverGpuVm::Object). + pub fn gem_offset(&self) -> u64 { + self.op.gem.offset + } + + /// The [`drm_gem_object`](DriverGpuVm::Object) to map. + pub fn obj(&self) -> &T::Object { + // SAFETY: The `obj` pointer is guaranteed to be valid. + unsafe { ::from_raw(self.op.gem.obj) } + } + + /// The [`GpuVmBo`] that the new VA will be associated with. + pub fn vm_bo(&self) -> &GpuVmBo { + self.vm_bo + } + + /// Use the pre-allocated VA to carry out this map operation. + pub fn insert(self, va: GpuVaAlloc, va_data: impl PinInit) -> OpMapped<'op, T> { + let va = va.prepare(va_data); + // SAFETY: By the type invariants we may access the interval tree. + unsafe { bindings::drm_gpuva_map(self.vm_bo.gpuvm().as_raw(), va, self.op) }; + + let _gpuva_guard = self.vm_bo().lock_gpuva(); + // SAFETY: The va is prepared for insertion, and we hold the GEM lock. + unsafe { bindings::drm_gpuva_link(va, self.vm_bo.as_raw()) }; + + OpMapped { + _invariant: self._invariant, + } + } +} + +/// Represents a completed [`OpMap`] operation. +pub struct OpMapped<'op, T> { + _invariant: PhantomData<*mut &'op mut T>, +} + /// Represents an `sm_step_unmap` operation that has not yet been completed. pub struct OpUnmap<'op, T: DriverGpuVm> { op: &'op bindings::drm_gpuva_op_unmap, @@ -213,6 +315,35 @@ pub struct OpRemapped<'op, T> { } impl UniqueRefGpuVm { + /// Create a mapping, removing or remapping anything that overlaps. + /// + /// Internally calls the [`DriverGpuVm`] callbacks similar to [`Self::sm_unmap`], except that + /// the [`DriverGpuVm::sm_step_map`] is called once to create the requested mapping. + #[inline] + pub fn sm_map(&mut self, req: OpMapRequest<'_, '_, T>) -> Result { + if req.vm_bo.gpuvm() != &**self { + return Err(EINVAL); + } + + let gpuvm = self.as_raw(); + let raw_req = req.raw_request(); + // INVARIANT: Checked above that `vm_bo.gpuvm() == self`. + let mut p = SmMapData { + sm_data: SmData { + gpuvm: self, + user_context: req.context, + }, + vm_bo: req.vm_bo, + }; + // SAFETY: + // * raw_request() creates a valid request. + // * The private data is valid to be interpreted as both SmData and SmMapData since the + // first field of SmMapData is SmData. + to_result(unsafe { + bindings::drm_gpuvm_sm_map(gpuvm, (&raw mut p).cast(), &raw const raw_req) + }) + } + /// Remove any mappings in the given region. /// /// Internally calls [`DriverGpuVm::sm_step_unmap`] for ranges entirely contained within the @@ -226,19 +357,45 @@ impl UniqueRefGpuVm { }; // SAFETY: // * raw_request() creates a valid request. - // * The private data is valid to be interpreted as SmData. + // * The private data is a valid SmData. to_result(unsafe { bindings::drm_gpuvm_sm_unmap(gpuvm, (&raw mut p).cast(), addr, length) }) } } impl GpuVm { /// # Safety - /// Must be called from `sm_unmap` with a pointer to `SmData`. + /// Must be called from `sm_map` with a pointer to `SmMapData`. + pub(super) unsafe extern "C" fn sm_step_map( + op: *mut bindings::drm_gpuva_op, + p: *mut c_void, + ) -> c_int { + // SAFETY: If we reach `sm_step_map` then we were called from `sm_map` which always passes + // an `SmMapData` as private data. + let p = unsafe { &mut *p.cast::>() }; + let op = OpMap { + // SAFETY: sm_step_map is called with a map operation. + op: unsafe { &(*op).__bindgen_anon_1.map }, + vm_bo: p.vm_bo, + _invariant: PhantomData, + }; + match p + .sm_data + .gpuvm + .data() + .sm_step_map(op, p.sm_data.user_context) + { + Ok(OpMapped { .. }) => 0, + Err(err) => err.to_errno(), + } + } + + /// # Safety + /// Must be called from `sm_map` or `sm_unmap` with a pointer to `SmMapData` or `SmData`. pub(super) unsafe extern "C" fn sm_step_unmap( op: *mut bindings::drm_gpuva_op, p: *mut c_void, ) -> c_int { - // SAFETY: The caller provides a pointer to `SmData`. + // SAFETY: The caller provides a pointer that can be treated as `SmData`. let p = unsafe { &mut *p.cast::>() }; let op = OpUnmap { // SAFETY: sm_step_unmap is called with an unmap operation. @@ -252,12 +409,12 @@ impl GpuVm { } /// # Safety - /// Must be called from `sm_unmap` with a pointer to `SmData`. + /// Must be called from `sm_map` or `sm_unmap` with a pointer to `SmMapData` or `SmData`. pub(super) unsafe extern "C" fn sm_step_remap( op: *mut bindings::drm_gpuva_op, p: *mut c_void, ) -> c_int { - // SAFETY: The caller provides a pointer to `SmData`. + // SAFETY: The caller provides a pointer that can be treated as `SmData`. let p = unsafe { &mut *p.cast::>() }; let op = OpRemap { // SAFETY: sm_step_remap is called with a remap operation.