gpu: nova-core: register: use field type for Into implementation

The getter method of a field works with the field type, but its setter
expects the type of the register. This leads to an asymmetry in the
From/Into implementations required for a field with a dedicated type.
For instance, a field declared as

    pub struct ControlReg(u32) {
        3:0 mode as u8 ?=> Mode;
        ...
    }

currently requires the following implementations:

    impl TryFrom<u8> for Mode {
      ...
    }

    impl From<Mode> for u32 {
      ...
    }

Change this so the `From<Mode>` now needs to be implemented for `u8`,
i.e. the primitive type of the field. This is more consistent, and will
become a requirement once we start using the TryFrom/Into derive macros
to implement these automatically.

Reported-by: Edwin Peer <epeer@nvidia.com>
Closes: https://lore.kernel.org/rust-for-linux/F3853912-2C1C-4F9B-89B0-3168689F35B3@nvidia.com/
Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Message-ID: <20251016151323.1201196-2-joelagnelf@nvidia.com>

1 files changed, 5 insertions, 5 deletions

diff --git a/drivers/gpu/nova-core/regs/macros.rs b/drivers/gpu/nova-core/regs/macros.rs
index 8058e1696df9..1c54a4533822 100644
--- a/drivers/gpu/nova-core/regs/macros.rs
+++ b/drivers/gpu/nova-core/regs/macros.rs
@@ -482,7 +482,7 @@ macro_rules! register {
         register!(
             @leaf_accessor $name $hi:$lo $field
             { |f| <$into_type>::from(if f != 0 { true } else { false }) }
-            $into_type => $into_type $(, $comment)?;
+            bool $into_type => $into_type $(, $comment)?;
         );
     };
 
@@ -499,7 +499,7 @@ macro_rules! register {
             $(, $comment:literal)?;
     ) => {
         register!(@leaf_accessor $name $hi:$lo $field
-            { |f| <$try_into_type>::try_from(f as $type) } $try_into_type =>
+            { |f| <$try_into_type>::try_from(f as $type) } $type $try_into_type =>
             ::core::result::Result<
                 $try_into_type,
                 <$try_into_type as ::core::convert::TryFrom<$type>>::Error
@@ -513,7 +513,7 @@ macro_rules! register {
             $(, $comment:literal)?;
     ) => {
         register!(@leaf_accessor $name $hi:$lo $field
-            { |f| <$into_type>::from(f as $type) } $into_type => $into_type $(, $comment)?;);
+            { |f| <$into_type>::from(f as $type) } $type $into_type => $into_type $(, $comment)?;);
     };
 
     // Shortcut for non-boolean fields defined without the `=>` or `?=>` syntax.
@@ -527,7 +527,7 @@ macro_rules! register {
     // Generates the accessor methods for a single field.
     (
         @leaf_accessor $name:ident $hi:tt:$lo:tt $field:ident
-            { $process:expr } $to_type:ty => $res_type:ty $(, $comment:literal)?;
+            { $process:expr } $prim_type:tt $to_type:ty => $res_type:ty $(, $comment:literal)?;
     ) => {
         ::kernel::macros::paste!(
         const [<$field:upper _RANGE>]: ::core::ops::RangeInclusive<u8> = $lo..=$hi;
@@ -559,7 +559,7 @@ macro_rules! register {
         pub(crate) fn [<set_ $field>](mut self, value: $to_type) -> Self {
             const MASK: u32 = $name::[<$field:upper _MASK>];
             const SHIFT: u32 = $name::[<$field:upper _SHIFT>];
-            let value = (u32::from(value) << SHIFT) & MASK;
+            let value = (u32::from($prim_type::from(value)) << SHIFT) & MASK;
             self.0 = (self.0 & !MASK) | value;
 
             self