> On 18 Jul 2025, at 04:26, Alexandre Courbot <[email protected]> wrote:
>
> The `Default` implementation of a register should be the aggregate of
> the default values of all its fields, and not simply be zeroed.
>
> Signed-off-by: Alexandre Courbot <[email protected]>
> ---
> drivers/gpu/nova-core/regs/macros.rs | 26 +++++++++++++++++++++++---
> 1 file changed, 23 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/nova-core/regs/macros.rs
> b/drivers/gpu/nova-core/regs/macros.rs
> index
> 485cac806e4a6578059c657f3b31f15e361becbd..f0942dc29210f703fddd4d86b758173f75b3477a
> 100644
> --- a/drivers/gpu/nova-core/regs/macros.rs
> +++ b/drivers/gpu/nova-core/regs/macros.rs
> @@ -112,14 +112,14 @@ macro_rules! register {
>
> // All rules below are helpers.
>
> - // Defines the wrapper `$name` type, as well as its relevant
> implementations (`Debug`, `BitOr`,
> - // and conversion to the value type) and field accessor methods.
> + // Defines the wrapper `$name` type, as well as its relevant
> implementations (`Debug`,
> + // `Default`, `BitOr`, and conversion to the value type) and field
> accessor methods.
> (@core $name:ident $(, $comment:literal)? { $($fields:tt)* }) => {
> $(
> #[doc=$comment]
> )?
> #[repr(transparent)]
> - #[derive(Clone, Copy, Default)]
> + #[derive(Clone, Copy)]
> pub(crate) struct $name(u32);
>
> impl ::core::ops::BitOr for $name {
> @@ -162,6 +162,7 @@ fn from(reg: $name) -> u32 {
> )*
> });
> register!(@debug $name { $($field;)* });
> + register!(@default $name { $($field;)* });
> };
>
> // Defines all the field getter/methods methods for `$name`.
> @@ -321,6 +322,25 @@ fn fmt(&self, f: &mut ::core::fmt::Formatter<'_>) ->
> ::core::fmt::Result {
> }
> };
>
> + // Generates the `Default` implementation for `$name`.
> + (@default $name:ident { $($field:ident;)* }) => {
> + /// Returns a value for the register where all fields are set to
> their default value.
> + impl ::core::default::Default for $name {
> + fn default() -> Self {
> + #[allow(unused_mut)]
> + let mut value = Self(Default::default());
> +
> + ::kernel::macros::paste!(
> + $(
> + value.[<set_ $field>](Default::default());
> + )*
> + );
> +
> + value
> + }
> + }
> + };
> +
> // Generates the IO accessors for a fixed offset register.
> (@io $name:ident @ $offset:expr) => {
> #[allow(dead_code)]
>
> --
> 2.50.1
>
>
Also very neat.
Reviewed-by: Daniel Almeida <[email protected]>
