gpu: nova-core: use Alignment for alignment-related operations

Make use of the newly-available `Alignment` type and remove the
corresponding TODO item.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

Author: Gnurou

Documentation/gpu/nova/core/todo.rst

@@ -147,7 +147,6 @@ Numerical operations [NUMM]
 Nova uses integer operations that are not part of the standard library (or not
 implemented in an optimized way for the kernel). These include:
 
-- Aligning up and down to a power of two,
 - The "Find Last Set Bit" (`fls` function of the C part of the kernel)
   operation.
 

drivers/gpu/nova-core/fb.rs

@@ -3,6 +3,7 @@
 use core::ops::Range;
 
 use kernel::prelude::*;
+use kernel::ptr::{Alignable, Alignment};
 use kernel::sizes::*;
 use kernel::types::ARef;
 use kernel::{dev_warn, device};
@@ -130,10 +131,9 @@ impl FbLayout {
         };
 
         let frts = {
-            const FRTS_DOWN_ALIGN: u64 = SZ_128K as u64;
+            const FRTS_DOWN_ALIGN: Alignment = Alignment::new::<SZ_128K>();
             const FRTS_SIZE: u64 = SZ_1M as u64;
-            // TODO[NUMM]: replace with `align_down` once it lands.
-            let frts_base = (vga_workspace.start & !(FRTS_DOWN_ALIGN - 1)) - FRTS_SIZE;
+            let frts_base = vga_workspace.start.align_down(FRTS_DOWN_ALIGN) - FRTS_SIZE;
 
             frts_base..frts_base + FRTS_SIZE
         };

drivers/gpu/nova-core/vbios.rs

@@ -10,6 +10,7 @@ use kernel::device;
 use kernel::error::Result;
 use kernel::pci;
 use kernel::prelude::*;
+use kernel::ptr::{Alignable, Alignment};
 
 /// The offset of the VBIOS ROM in the BAR0 space.
 const ROM_OFFSET: usize = 0x300000;
@@ -177,8 +178,7 @@ impl<'a> Iterator for VbiosIterator<'a> {
 
         // Advance to next image (aligned to 512 bytes).
         self.current_offset += image_size;
-        // TODO[NUMM]: replace with `align_up` once it lands.
-        self.current_offset = self.current_offset.next_multiple_of(512);
+        self.current_offset = self.current_offset.align_up(Alignment::new::<512>())?;
 
         Some(Ok(full_image))
     }