Introduce a trait for GPU Page Directory Entries (PDEs). Default `read()`/`write()` helpers via a `PraminWindow` are provided.
The forthcoming MMU v2, v3 PDE structs will each implement `PdeOps`, allowing the later page-table walker and mapper to call PDE operations. Signed-off-by: Joel Fernandes <[email protected]> --- drivers/gpu/nova-core/mm/pagetable.rs | 37 +++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/drivers/gpu/nova-core/mm/pagetable.rs b/drivers/gpu/nova-core/mm/pagetable.rs index a92add82eb10..1c94b3afa8b2 100644 --- a/drivers/gpu/nova-core/mm/pagetable.rs +++ b/drivers/gpu/nova-core/mm/pagetable.rs @@ -122,6 +122,43 @@ fn write(&self, window: &mut pramin::PraminWindow<'_>, addr: VramAddress) -> Res } } +/// Operations on Page Directory Entries (`PDE`s). +pub(super) trait PdeOps: Copy + core::fmt::Debug + Into<u64> { + /// Create a `PDE` from a raw `u64` value. + fn from_raw(val: u64) -> Self; + + /// Create a valid `PDE` pointing to a page table in the given aperture. + fn new(aperture: AperturePde, table_pfn: Pfn) -> Self; + + /// Create an invalid `PDE`. + fn invalid() -> Self; + + /// Check if this `PDE` is valid. + fn is_valid(&self) -> bool; + + /// Get the memory aperture of this `PDE`. + fn aperture(&self) -> AperturePde; + + /// Get the VRAM address of the page table. + fn table_vram_address(&self) -> VramAddress; + + /// Read a `PDE` from VRAM. + fn read(window: &mut pramin::PraminWindow<'_>, addr: VramAddress) -> Result<Self> { + let val = window.try_read64(addr)?; + Ok(Self::from_raw(val)) + } + + /// Write this `PDE` to VRAM. + fn write(&self, window: &mut pramin::PraminWindow<'_>, addr: VramAddress) -> Result { + window.try_write64(addr, (*self).into()) + } + + /// Check if this `PDE` is valid and points to video memory. + fn is_valid_vram(&self) -> bool { + self.is_valid() && self.aperture() == AperturePde::VideoMemory + } +} + /// Memory aperture for Page Table Entries (`PTE`s). /// /// Determines which memory region the `PTE` points to. -- 2.34.1
