gpu: nova-core: bitfield: Add support for custom visibility

Add support for custom visibility to allow for users to control
visibility of the structure and helpers.

Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Reviewed-by: Edwin Peer <epeer@nvidia.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
[acourbot@nvidia.com: fix long lines warnings and typo in commit message.]
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Message-ID: <20251016151323.1201196-5-joelagnelf@nvidia.com>

2 files changed, 39 insertions, 32 deletions

diff --git a/drivers/gpu/nova-core/bitfield.rs b/drivers/gpu/nova-core/bitfield.rs
index eff938937df4..25579b4c328f 100644
--- a/drivers/gpu/nova-core/bitfield.rs
+++ b/drivers/gpu/nova-core/bitfield.rs
@@ -60,7 +60,7 @@
 /// }
 ///
 /// bitfield! {
-///     struct ControlReg(u32) {
+///     pub struct ControlReg(u32) {
 ///         7:7 state as bool => State;
 ///         3:0 mode as u8 ?=> Mode;
 ///     }
@@ -74,6 +74,9 @@
 ///   struct's storage size.
 /// - Debug and Default implementations.
 ///
+/// Note: Field accessors and setters inherit the same visibility as the struct itself.
+/// In the example above, both `mode()` and `set_mode()` methods will be `pub`.
+///
 /// Fields are defined as follows:
 ///
 /// - `as <type>` simply returns the field value casted to <type>, typically `u32`, `u16`, `u8` or
@@ -84,21 +87,21 @@
 ///   and returns the result. This is useful with fields for which not all values are valid.
 macro_rules! bitfield {
     // Main entry point - defines the bitfield struct with fields
-    (struct $name:ident($storage:ty) $(, $comment:literal)? { $($fields:tt)* }) => {
-        bitfield!(@core $name $storage $(, $comment)? { $($fields)* });
+    ($vis:vis struct $name:ident($storage:ty) $(, $comment:literal)? { $($fields:tt)* }) => {
+        bitfield!(@core $vis $name $storage $(, $comment)? { $($fields)* });
     };
 
     // All rules below are helpers.
 
     // Defines the wrapper `$name` type, as well as its relevant implementations (`Debug`,
     // `Default`, `BitOr`, and conversion to the value type) and field accessor methods.
-    (@core $name:ident $storage:ty $(, $comment:literal)? { $($fields:tt)* }) => {
+    (@core $vis:vis $name:ident $storage:ty $(, $comment:literal)? { $($fields:tt)* }) => {
         $(
         #[doc=$comment]
         )?
         #[repr(transparent)]
         #[derive(Clone, Copy)]
-        pub(crate) struct $name($storage);
+        $vis struct $name($storage);
 
         impl ::core::ops::BitOr for $name {
             type Output = Self;
@@ -114,14 +117,14 @@ macro_rules! bitfield {
             }
         }
 
-        bitfield!(@fields_dispatcher $name $storage { $($fields)* });
+        bitfield!(@fields_dispatcher $vis $name $storage { $($fields)* });
     };
 
     // Captures the fields and passes them to all the implementers that require field information.
     //
     // Used to simplify the matching rules for implementers, so they don't need to match the entire
     // complex fields rule even though they only make use of part of it.
-    (@fields_dispatcher $name:ident $storage:ty {
+    (@fields_dispatcher $vis:vis $name:ident $storage:ty {
         $($hi:tt:$lo:tt $field:ident as $type:tt
             $(?=> $try_into_type:ty)?
             $(=> $into_type:ty)?
@@ -130,7 +133,7 @@ macro_rules! bitfield {
         )*
     }
     ) => {
-        bitfield!(@field_accessors $name $storage {
+        bitfield!(@field_accessors $vis $name $storage {
             $(
                 $hi:$lo $field as $type
                 $(?=> $try_into_type)?
@@ -145,7 +148,7 @@ macro_rules! bitfield {
 
     // Defines all the field getter/setter methods for `$name`.
     (
-        @field_accessors $name:ident $storage:ty {
+        @field_accessors $vis:vis $name:ident $storage:ty {
         $($hi:tt:$lo:tt $field:ident as $type:tt
             $(?=> $try_into_type:ty)?
             $(=> $into_type:ty)?
@@ -161,7 +164,7 @@ macro_rules! bitfield {
         #[allow(dead_code)]
         impl $name {
             $(
-            bitfield!(@field_accessor $name $storage, $hi:$lo $field as $type
+            bitfield!(@field_accessor $vis $name $storage, $hi:$lo $field as $type
                 $(?=> $try_into_type)?
                 $(=> $into_type)?
                 $(, $comment)?
@@ -195,11 +198,11 @@ macro_rules! bitfield {
 
     // Catches fields defined as `bool` and convert them into a boolean value.
     (
-        @field_accessor $name:ident $storage:ty, $hi:tt:$lo:tt $field:ident as bool => $into_type:ty
-            $(, $comment:literal)?;
+        @field_accessor $vis:vis $name:ident $storage:ty, $hi:tt:$lo:tt $field:ident as bool
+            => $into_type:ty $(, $comment:literal)?;
     ) => {
         bitfield!(
-            @leaf_accessor $name $storage, $hi:$lo $field
+            @leaf_accessor $vis $name $storage, $hi:$lo $field
             { |f| <$into_type>::from(if f != 0 { true } else { false }) }
             bool $into_type => $into_type $(, $comment)?;
         );
@@ -207,18 +210,20 @@ macro_rules! bitfield {
 
     // Shortcut for fields defined as `bool` without the `=>` syntax.
     (
-        @field_accessor $name:ident $storage:ty, $hi:tt:$lo:tt $field:ident as bool
+        @field_accessor $vis:vis $name:ident $storage:ty, $hi:tt:$lo:tt $field:ident as bool
             $(, $comment:literal)?;
     ) => {
-        bitfield!(@field_accessor $name $storage, $hi:$lo $field as bool => bool $(, $comment)?;);
+        bitfield!(
+            @field_accessor $vis $name $storage, $hi:$lo $field as bool => bool $(, $comment)?;
+        );
     };
 
     // Catches the `?=>` syntax for non-boolean fields.
     (
-        @field_accessor $name:ident $storage:ty, $hi:tt:$lo:tt $field:ident as $type:tt
+        @field_accessor $vis:vis $name:ident $storage:ty, $hi:tt:$lo:tt $field:ident as $type:tt
             ?=> $try_into_type:ty $(, $comment:literal)?;
     ) => {
-        bitfield!(@leaf_accessor $name $storage, $hi:$lo $field
+        bitfield!(@leaf_accessor $vis $name $storage, $hi:$lo $field
             { |f| <$try_into_type>::try_from(f as $type) } $type $try_into_type =>
             ::core::result::Result<
                 $try_into_type,
@@ -229,24 +234,26 @@ macro_rules! bitfield {
 
     // Catches the `=>` syntax for non-boolean fields.
     (
-        @field_accessor $name:ident $storage:ty, $hi:tt:$lo:tt $field:ident as $type:tt
+        @field_accessor $vis:vis $name:ident $storage:ty, $hi:tt:$lo:tt $field:ident as $type:tt
             => $into_type:ty $(, $comment:literal)?;
     ) => {
-        bitfield!(@leaf_accessor $name $storage, $hi:$lo $field
+        bitfield!(@leaf_accessor $vis $name $storage, $hi:$lo $field
             { |f| <$into_type>::from(f as $type) } $type $into_type => $into_type $(, $comment)?;);
     };
 
     // Shortcut for non-boolean fields defined without the `=>` or `?=>` syntax.
     (
-        @field_accessor $name:ident $storage:ty, $hi:tt:$lo:tt $field:ident as $type:tt
+        @field_accessor $vis:vis $name:ident $storage:ty, $hi:tt:$lo:tt $field:ident as $type:tt
             $(, $comment:literal)?;
     ) => {
-        bitfield!(@field_accessor $name $storage, $hi:$lo $field as $type => $type $(, $comment)?;);
+        bitfield!(
+            @field_accessor $vis $name $storage, $hi:$lo $field as $type => $type $(, $comment)?;
+        );
     };
 
     // Generates the accessor methods for a single field.
     (
-        @leaf_accessor $name:ident $storage:ty, $hi:tt:$lo:tt $field:ident
+        @leaf_accessor $vis:vis $name:ident $storage:ty, $hi:tt:$lo:tt $field:ident
             { $process:expr } $prim_type:tt $to_type:ty => $res_type:ty $(, $comment:literal)?;
     ) => {
         ::kernel::macros::paste!(
@@ -269,7 +276,7 @@ macro_rules! bitfield {
         #[doc=$comment]
         )?
         #[inline(always)]
-        pub(crate) fn $field(self) -> $res_type {
+        $vis fn $field(self) -> $res_type {
             ::kernel::macros::paste!(
             const MASK: $storage = $name::[<$field:upper _MASK>];
             const SHIFT: u32 = $name::[<$field:upper _SHIFT>];
@@ -285,7 +292,7 @@ macro_rules! bitfield {
         #[doc=$comment]
         )?
         #[inline(always)]
-        pub(crate) fn [<set_ $field>](mut self, value: $to_type) -> Self {
+        $vis fn [<set_ $field>](mut self, value: $to_type) -> Self {
             const MASK: $storage = $name::[<$field:upper _MASK>];
             const SHIFT: u32 = $name::[<$field:upper _SHIFT>];
             let value = ($storage::from($prim_type::from(value)) << SHIFT) & MASK;
diff --git a/drivers/gpu/nova-core/regs/macros.rs b/drivers/gpu/nova-core/regs/macros.rs
index ffd7d5cb73bb..c0a5194e8d97 100644
--- a/drivers/gpu/nova-core/regs/macros.rs
+++ b/drivers/gpu/nova-core/regs/macros.rs
@@ -276,25 +276,25 @@ pub(crate) trait RegisterBase<T> {
 macro_rules! register {
     // Creates a register at a fixed offset of the MMIO space.
     ($name:ident @ $offset:literal $(, $comment:literal)? { $($fields:tt)* } ) => {
-        bitfield!(struct $name(u32) $(, $comment)? { $($fields)* } );
+        bitfield!(pub(crate) struct $name(u32) $(, $comment)? { $($fields)* } );
         register!(@io_fixed $name @ $offset);
     };
 
     // Creates an alias register of fixed offset register `alias` with its own fields.
     ($name:ident => $alias:ident $(, $comment:literal)? { $($fields:tt)* } ) => {
-        bitfield!(struct $name(u32) $(, $comment)? { $($fields)* } );
+        bitfield!(pub(crate) struct $name(u32) $(, $comment)? { $($fields)* } );
         register!(@io_fixed $name @ $alias::OFFSET);
     };
 
     // Creates a register at a relative offset from a base address provider.
     ($name:ident @ $base:ty [ $offset:literal ] $(, $comment:literal)? { $($fields:tt)* } ) => {
-        bitfield!(struct $name(u32) $(, $comment)? { $($fields)* } );
+        bitfield!(pub(crate) struct $name(u32) $(, $comment)? { $($fields)* } );
         register!(@io_relative $name @ $base [ $offset ]);
     };
 
     // Creates an alias register of relative offset register `alias` with its own fields.
     ($name:ident => $base:ty [ $alias:ident ] $(, $comment:literal)? { $($fields:tt)* }) => {
-        bitfield!(struct $name(u32) $(, $comment)? { $($fields)* } );
+        bitfield!(pub(crate) struct $name(u32) $(, $comment)? { $($fields)* } );
         register!(@io_relative $name @ $base [ $alias::OFFSET ]);
     };
 
@@ -305,7 +305,7 @@ macro_rules! register {
         }
     ) => {
         static_assert!(::core::mem::size_of::<u32>() <= $stride);
-        bitfield!(struct $name(u32) $(, $comment)? { $($fields)* } );
+        bitfield!(pub(crate) struct $name(u32) $(, $comment)? { $($fields)* } );
         register!(@io_array $name @ $offset [ $size ; $stride ]);
     };
 
@@ -326,7 +326,7 @@ macro_rules! register {
             $(, $comment:literal)? { $($fields:tt)* }
     ) => {
         static_assert!(::core::mem::size_of::<u32>() <= $stride);
-        bitfield!(struct $name(u32) $(, $comment)? { $($fields)* } );
+        bitfield!(pub(crate) struct $name(u32) $(, $comment)? { $($fields)* } );
         register!(@io_relative_array $name @ $base [ $offset [ $size ; $stride ] ]);
     };
 
@@ -348,7 +348,7 @@ macro_rules! register {
         }
     ) => {
         static_assert!($idx < $alias::SIZE);
-        bitfield!(struct $name(u32) $(, $comment)? { $($fields)* } );
+        bitfield!(pub(crate) struct $name(u32) $(, $comment)? { $($fields)* } );
         register!(@io_relative $name @ $base [ $alias::OFFSET + $idx * $alias::STRIDE ] );
     };
 
@@ -357,7 +357,7 @@ macro_rules! register {
     // to avoid it being interpreted in place of the relative register array alias rule.
     ($name:ident => $alias:ident [ $idx:expr ] $(, $comment:literal)? { $($fields:tt)* }) => {
         static_assert!($idx < $alias::SIZE);
-        bitfield!(struct $name(u32) $(, $comment)? { $($fields)* } );
+        bitfield!(pub(crate) struct $name(u32) $(, $comment)? { $($fields)* } );
         register!(@io_fixed $name @ $alias::OFFSET + $idx * $alias::STRIDE );
     };