// SPDX-License-Identifier: GPL-2.0 OR MIT use super::*; /// Represents that a given GEM object has at least one mapping on this [`GpuVm`] instance.////// Does not assume that GEM lock is held.////// # Invariants////// * Allocated with `kmalloc` and refcounted via `inner`./// * Is present in the gem list.#[repr(C)]#[pin_data]pub struct GpuVmBo<T: DriverGpuVm> {    #[pin]    inner: Opaque<bindings::drm_gpuvm_bo>,    #[pin]    data: T::VmBoData,} // SAFETY: It is safe to send a `GpuVmBo<T>` to another thread: dropping it there drops// `T::VmBoData` and the GEM `T::Object`, both `Send` by the `DriverGpuVm` bounds.unsafe impl<T: DriverGpuVm> Send for GpuVmBo<T> {} // SAFETY: It is safe to share a `&GpuVmBo<T>` between threads: it effectively shares// `&T::VmBoData` and the GEM `&T::Object` (both `Sync`), and any thread may upgrade to an// `ARef` and ultimately drop them (both `Send`), per the `DriverGpuVm` bounds.unsafe impl<T: DriverGpuVm> Sync for GpuVmBo<T> {} // SAFETY: By type invariants, the allocation is managed by the refcount in `self.inner`.unsafe impl<T: DriverGpuVm> AlwaysRefCounted for GpuVmBo<T> {    fn inc_ref(&self) {        // SAFETY: By type invariants, the allocation is managed by the refcount in `self.inner`.        unsafe { bindings::drm_gpuvm_bo_get(self.inner.get()) };    }     unsafe fn dec_ref(obj: NonNull<Self>) {        // CAST: `drm_gpuvm_bo` is first field of repr(C) struct.        // SAFETY: By type invariants, the allocation is managed by the refcount in `self.inner`.        // This GPUVM instance uses immediate mode, so we may put the refcount using the deferred        // mechanism.        unsafe { bindings::drm_gpuvm_bo_put_deferred(obj.as_ptr().cast()) };    }} impl<T: DriverGpuVm> PartialEq for GpuVmBo<T> {    #[inline]    fn eq(&self, other: &Self) -> bool {        core::ptr::eq(self.as_raw(), other.as_raw())    }}impl<T: DriverGpuVm> Eq for GpuVmBo<T> {} impl<T: DriverGpuVm> GpuVmBo<T> {    /// The function pointer for allocating a GpuVmBo stored in the gpuvm vtable.    ///    /// Allocation is always implemented according to [`Self::vm_bo_alloc`], but it is set to    /// `None` if the default gpuvm behavior is the same as `vm_bo_alloc`.    ///    /// This may be `Some` even if `FREE_FN` is `None`, or vice-versa.    pub(super) const ALLOC_FN: Option<unsafe extern "C" fn() -> *mut bindings::drm_gpuvm_bo> = {        use core::alloc::Layout;        let base = Layout::new::<bindings::drm_gpuvm_bo>();        let rust = Layout::new::<Self>();        assert!(base.size() <= rust.size());        if base.size() != rust.size() || base.align() != rust.align() {            Some(Self::vm_bo_alloc)        } else {            // This causes GPUVM to allocate a `GpuVmBo<T>` with `kzalloc(sizeof(drm_gpuvm_bo))`.            None        }    };     /// The function pointer for freeing a GpuVmBo stored in the gpuvm vtable.    ///    /// Freeing is always implemented according to [`Self::vm_bo_free`], but it is set to `None` if    /// the default gpuvm behavior is the same as `vm_bo_free`.    ///    /// This may be `Some` even if `ALLOC_FN` is `None`, or vice-versa.    pub(super) const FREE_FN: Option<unsafe extern "C" fn(*mut bindings::drm_gpuvm_bo)> = {        if core::mem::needs_drop::<Self>() {            Some(Self::vm_bo_free)        } else {            // This causes GPUVM to free a `GpuVmBo<T>` with `kfree`.            None        }    };     /// Custom function for allocating a `drm_gpuvm_bo`.    ///    /// # Safety    ///    /// Always safe to call.    unsafe extern "C" fn vm_bo_alloc() -> *mut bindings::drm_gpuvm_bo {        let raw_ptr = KBox::<Self>::new_uninit(GFP_KERNEL | __GFP_ZERO)            .map(KBox::into_raw)            .unwrap_or(ptr::null_mut());         // CAST: `drm_gpuvm_bo` is first field of `Self`.        raw_ptr.cast()    }     /// Custom function for freeing a `drm_gpuvm_bo`.    ///    /// # Safety    ///    /// The pointer must have been allocated with [`GpuVmBo::ALLOC_FN`], and must not be used after    /// this call.    unsafe extern "C" fn vm_bo_free(ptr: *mut bindings::drm_gpuvm_bo) {        // CAST: `drm_gpuvm_bo` is first field of `Self`.        // SAFETY:        // * The ptr was allocated from kmalloc with the layout of `GpuVmBo<T>`.        // * `ptr->inner` has no destructor.        // * `ptr->data` contains a valid `T::VmBoData` that we can drop.        drop(unsafe { KBox::<Self>::from_raw(ptr.cast()) });    }     /// Access this [`GpuVmBo`] from a raw pointer.    ///    /// # Safety    ///    /// 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]    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() }    }     /// Returns a raw pointer to underlying C value.    #[inline]    pub fn as_raw(&self) -> *mut bindings::drm_gpuvm_bo {        self.inner.get()    }     /// The [`GpuVm`] that this GEM object is mapped in.    #[inline]    pub fn gpuvm(&self) -> &GpuVm<T> {        // SAFETY: The `obj` pointer is guaranteed to be valid.        unsafe { GpuVm::<T>::from_raw((*self.inner.get()).vm) }    }     /// The [`drm_gem_object`](DriverGpuVm::Object) for these mappings.    #[inline]    pub fn obj(&self) -> &T::Object {        // SAFETY: The `obj` pointer is guaranteed to be valid.        unsafe { <T::Object as IntoGEMObject>::from_raw((*self.inner.get()).obj) }    }     /// The driver data with this buffer object.    #[inline]    pub fn data(&self) -> &T::VmBoData {        &self.data    }     pub(super) fn lock_gpuva(&self) -> crate::sync::MutexGuard<'_, ()> {        // SAFETY: The GEM object is valid.        let ptr = unsafe { &raw mut (*self.obj().as_raw()).gpuva.lock };        // SAFETY: The GEM object is valid, so the mutex is properly initialized.        let mutex = unsafe { crate::sync::Mutex::from_raw(ptr) };        mutex.lock()    }} /// A pre-allocated [`GpuVmBo`] object.////// # Invariants////// Points at a `drm_gpuvm_bo` that contains a valid `T::VmBoData`, has a refcount of one, and is/// absent from any gem, extobj, or evict lists.pub(super) struct GpuVmBoAlloc<T: DriverGpuVm>(NonNull<GpuVmBo<T>>); impl<T: DriverGpuVm> GpuVmBoAlloc<T> {    /// Create a new pre-allocated [`GpuVmBo`].    ///    /// It's intentional that the initializer is infallible because `drm_gpuvm_bo_put` will call    /// drop on the data, so we don't have a way to free it when the data is missing.    #[inline]    pub(super) fn new(        gpuvm: &GpuVm<T>,        gem: &T::Object,        value: impl PinInit<T::VmBoData>,    ) -> Result<GpuVmBoAlloc<T>, AllocError> {        // CAST: `GpuVmBoAlloc::vm_bo_alloc` ensures that this memory was allocated with the layout        // of `GpuVmBo<T>`. The type is repr(C), so `container_of` is not required.        // SAFETY: The provided gpuvm and gem ptrs are valid for the duration of this call.        let raw_ptr = unsafe {            bindings::drm_gpuvm_bo_create(gpuvm.as_raw(), gem.as_raw()).cast::<GpuVmBo<T>>()        };        let ptr = NonNull::new(raw_ptr).ok_or(AllocError)?;        // SAFETY: `ptr->data` is a valid pinned location.        unsafe { pin_init::raw_init(&raw mut (*raw_ptr).data, value) };        // INVARIANTS: We just created the vm_bo so it's absent from lists, and the data is valid        // as we just initialized it.        Ok(GpuVmBoAlloc(ptr))    }     /// Returns a raw pointer to underlying C value.    #[inline]    pub(super) fn as_raw(&self) -> *mut bindings::drm_gpuvm_bo {        // SAFETY: The pointer references a valid `drm_gpuvm_bo`.        unsafe { (*self.0.as_ptr()).inner.get() }    }     /// Look up whether there is an existing [`GpuVmBo`] for this gem object.    ///    /// The caller should not hold the GEM mutex or DMA resv lock.    #[inline]    pub(super) fn obtain(self) -> ARef<GpuVmBo<T>> {        let me = ManuallyDrop::new(self);        // SAFETY: Valid `drm_gpuvm_bo` not already in the lists. We do not access `me` after this        // call.        let ptr = unsafe { bindings::drm_gpuvm_bo_obtain_prealloc(me.as_raw()) };         // SAFETY: `drm_gpuvm_bo_obtain_prealloc` always returns a non-null ptr        let nonnull = unsafe { NonNull::new_unchecked(ptr.cast()) };         // INVARIANTS: `drm_gpuvm_bo_obtain_prealloc` ensures that the bo is in the GEM list.        // SAFETY: We received one refcount from `drm_gpuvm_bo_obtain_prealloc`.        let ret = unsafe { ARef::<GpuVmBo<T>>::from_raw(nonnull) };         // Ensure that external objects are in the extobj list.        //        // Note that we must call `extobj_add` even if `ptr != me` to avoid a race condition where        // we could end up using the extobj before the thread with `ptr == me` calls extobj_add.        if ret.gpuvm().is_extobj(ret.obj()) {            let resv_lock = ret.gpuvm().raw_resv();            // TODO: Use a proper lock guard here once a dma_resv lock abstraction exists.            // SAFETY: The GPUVM is still alive, so its resv lock is too.            unsafe { bindings::dma_resv_lock(resv_lock, ptr::null_mut()) };            // SAFETY: We hold the GPUVMs resv lock.            unsafe { bindings::drm_gpuvm_bo_extobj_add(ptr) };            // SAFETY: We took the lock, so we can unlock it.            unsafe { bindings::dma_resv_unlock(resv_lock) };        }         ret    }} impl<T: DriverGpuVm> Deref for GpuVmBoAlloc<T> {    type Target = GpuVmBo<T>;    #[inline]    fn deref(&self) -> &GpuVmBo<T> {        // SAFETY: By the type invariants we may deref while `Self` exists.        unsafe { self.0.as_ref() }    }} impl<T: DriverGpuVm> Drop for GpuVmBoAlloc<T> {    #[inline]    fn drop(&mut self) {        // TODO: Call drm_gpuvm_bo_destroy_not_in_lists() directly.        // SAFETY: It's safe to perform a deferred put in any context.        unsafe { bindings::drm_gpuvm_bo_put_deferred(self.as_raw()) };    }}