From: Joel Fernandes <[email protected]> Introduce a trait for GPU Page Directory Entries (PDEs). Default `read()`/`write()` helpers via a `Pramin` 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]> [ecourtney: replace PraminWindow accesses with typed MMIO views] Signed-off-by: Eliot Courtney <[email protected]> --- drivers/gpu/nova-core/mm/pagetable.rs | 41 +++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) diff --git a/drivers/gpu/nova-core/mm/pagetable.rs b/drivers/gpu/nova-core/mm/pagetable.rs index a23370b4b62d..14436fa6adf0 100644 --- a/drivers/gpu/nova-core/mm/pagetable.rs +++ b/drivers/gpu/nova-core/mm/pagetable.rs @@ -128,6 +128,47 @@ fn write(&self, pramin: &mut pramin::Pramin<'_>, addr: VramAddress) -> Result { } } +/// 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(pramin: &mut pramin::Pramin<'_>, addr: VramAddress) -> Result<Self> { + let val = pramin.window_at::<u64>(addr)?.view().read_val(); + Ok(Self::from_raw(val)) + } + + /// Write this `PDE` to VRAM. + fn write(&self, pramin: &mut pramin::Pramin<'_>, addr: VramAddress) -> Result { + pramin + .window_at::<u64>(addr)? + .view() + .write_val((*self).into()); + Ok(()) + } + + /// 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. -- 2.55.0
