Add an iterator over VA mappings so drivers can walk and dump GPU VA state in debugfs.
Signed-off-by: Alvin Sun <[email protected]> --- rust/kernel/drm/gpuvm/mod.rs | 6 +++++ rust/kernel/drm/gpuvm/va.rs | 53 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 59 insertions(+) diff --git a/rust/kernel/drm/gpuvm/mod.rs b/rust/kernel/drm/gpuvm/mod.rs index 3186df9f740cf..41b99d468f9d9 100644 --- a/rust/kernel/drm/gpuvm/mod.rs +++ b/rust/kernel/drm/gpuvm/mod.rs @@ -301,6 +301,12 @@ pub fn data(&mut self) -> &mut T { // SAFETY: By the type invariants we may access `core`. unsafe { &mut *self.0.data.get() } } + + /// Returns an iterator over the VA mappings in this GpuVm. + #[inline] + pub fn va_mappings(&self) -> GpuVaIter<'_, T> { + GpuVaIter::new(&self.0) + } } impl<T: DriverGpuVm> Deref for GpuVmCore<T> { diff --git a/rust/kernel/drm/gpuvm/va.rs b/rust/kernel/drm/gpuvm/va.rs index 8b8fd500b3c5f..3210047f880e3 100644 --- a/rust/kernel/drm/gpuvm/va.rs +++ b/rust/kernel/drm/gpuvm/va.rs @@ -1,6 +1,14 @@ // SPDX-License-Identifier: GPL-2.0 OR MIT use super::*; +use crate::interop::list::{ + CList, + CListIter, // +}; +use core::{ + marker::PhantomData, + mem::offset_of, // +}; /// Represents that a range of a GEM object is mapped in this [`GpuVm`] instance. /// @@ -118,6 +126,51 @@ pub fn length(&self) -> u64 { } } +const DRM_GPUVA_LIST_ENTRY_OFFSET: usize = offset_of!(bindings::drm_gpuva, rb.entry); +type RawGpuVaIter<'a> = CListIter<'a, RawGpuVa, DRM_GPUVA_LIST_ENTRY_OFFSET>; + +/// An iterator over the VA mappings in a [`GpuVm`]. +pub struct GpuVaIter<'a, T: DriverGpuVm> { + raw_gpuva_iter: RawGpuVaIter<'a>, + kern_gpuva_ptr: *mut bindings::drm_gpuva, + _marker: PhantomData<&'a T>, +} + +impl<'a, T: DriverGpuVm> GpuVaIter<'a, T> { + #[inline] + pub(crate) fn new(gpuvm: &'a GpuVm<T>) -> Self { + // SAFETY: `gpuvm` is valid. + let head = unsafe { &raw mut (*gpuvm.as_raw()).rb.list }; + // SAFETY: `head` is a valid pointer to a drm_gpuva list head. + let clist = unsafe { CList::<RawGpuVa, DRM_GPUVA_LIST_ENTRY_OFFSET>::from_raw(head) }; + let kern_gpuva_ptr = gpuvm.kernel_alloc_va().as_raw(); + + Self { + raw_gpuva_iter: clist.iter(), + kern_gpuva_ptr, + _marker: PhantomData, + } + } +} + +impl<'a, T: DriverGpuVm> Iterator for GpuVaIter<'a, T> { + type Item = &'a GpuVa<T>; + + #[inline] + fn next(&mut self) -> Option<Self::Item> { + let mut curr = self.raw_gpuva_iter.next()?; + + if curr.as_raw() == self.kern_gpuva_ptr { + // Skip kernel reserved node. + curr = self.raw_gpuva_iter.next()?; + } + + // SAFETY: We have skipped the kernel reserved node, all remaining + // entries are valid GpuVa<T> instances. + Some(unsafe { GpuVa::from_raw(curr.as_raw()) }) + } +} + /// A pre-allocated [`GpuVa`] object. /// /// # Invariants -- 2.43.0
