Re: [PATCH] drm/tyr: use bitfield! for non-MMIO fields

[Gary Guo]

On Fri Sep 11, 2026 at 1:06 AM BST, Deborah Brouwer wrote:
> SectionFlags and MMU_MEMATTR_STAGE1 describe bitfields rather than
> hardware registers. Use bitfield! instead of register! so they aren't
> confused with actual registers.
>

I've sent
https://lore.kernel.org/dri-devel/20260910165734.80378-1-gary@xxxxxxxxxx/
already.

Best,
Gary

> Signed-off-by: Deborah Brouwer <deborah.brouwer@xxxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/tyr/fw.rs   | 11 ++++-------
>  drivers/gpu/drm/tyr/regs.rs | 11 +++++------
>  2 files changed, 9 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/gpu/drm/tyr/fw.rs b/drivers/gpu/drm/tyr/fw.rs
> index 7edb5eff1707..8d11f888a9b9 100644
> --- a/drivers/gpu/drm/tyr/fw.rs
> +++ b/drivers/gpu/drm/tyr/fw.rs
> @@ -14,6 +14,7 @@
>  //! [`Section`]: crate::fw::Section
>  
>  use kernel::{
> +    bitfield,
>      device::{
>          Bound,
>          Device, //
> @@ -27,7 +28,6 @@
>      },
>      num::Bounded,
>      prelude::*,
> -    register,
>      str::CString,
>      sync::{
>          Arc,
> @@ -39,8 +39,7 @@
>  use crate::{
>      driver::{
>          IoMem,
> -        TyrDrmDevice,
> -        TyrRegisters, //
> +        TyrDrmDevice, //
>      },
>      fw::parser::{
>          FwParser,
> @@ -101,11 +100,9 @@ fn from(value: CacheMode) -> Self {
>      }
>  }
>  
> -register! {
> -    base: TyrRegisters;
> -
> +bitfield! {
>       #[allow(non_upper_case_globals)]
> -    pub(super) SectionFlags(u32) @ 0x0 {
> +    pub(super) struct SectionFlags(u32) {
>          0:0 read => bool;
>          1:1 write => bool;
>          2:2 exec => bool;
> diff --git a/drivers/gpu/drm/tyr/regs.rs b/drivers/gpu/drm/tyr/regs.rs
> index 0c419c4e1186..3377b8fc5029 100644
> --- a/drivers/gpu/drm/tyr/regs.rs
> +++ b/drivers/gpu/drm/tyr/regs.rs
> @@ -986,6 +986,7 @@ pub(crate) mod mmu_control {
>      /// This array contains 16 instances of the MMU_AS_CONTROL register page.
>      pub(crate) mod mmu_as_control {
>          use kernel::{
> +            bitfield,
>              num::Bounded,
>              prelude::*,
>              register, //
> @@ -1130,14 +1131,12 @@ fn from(val: MemoryType) -> Self {
>              }
>          }
>  
> -        register! {
> -            base: TyrRegisters;
> -
> +        bitfield! {
>              /// Stage 1 memory attributes (8-bit bitfield).
>              ///
> -            /// This is not an actual register, but a bitfield definition used by the MEMATTR
> -            /// register. Each of the 8 bytes in MEMATTR follows this layout.
> -            MMU_MEMATTR_STAGE1(u8) @ 0x0 {
> +            /// This bitfield definition is used by the MEMATTR register.
> +            /// Each of the 8 bytes in MEMATTR follows this layout.
> +            struct MMU_MEMATTR_STAGE1(u8) {
>                  /// Inner cache write allocation policy.
>                  0:0     alloc_w => bool;
>                  /// Inner cache read allocation policy.
>
> ---
> base-commit: 73e5616f3d197c1af5a04a481fe0f13aa3913bd1
> change-id: 20260910-b4-use-bitfield-512214360810
>
> Best regards,