Re: [PATCH v6 4/5] rust: Move register and bitfield macros out of Nova

["Alexandre Courbot" <acourbot@nvidia.com>]

On Sat Oct 4, 2025 at 12:47 AM JST, Joel Fernandes wrote:
> Out of broad need for the register and bitfield macros in Rust, move
> them out of nova into the kernel crate. Several usecases need them (Nova
> is already using these and Tyr developers said they need them).
>
> bitfield moved into kernel crate - defines bitfields in Rust.
> register moved into io module - defines hardware registers and accessors.
>
> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
> Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
> Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
> ---
>  drivers/gpu/nova-core/falcon.rs               |  2 +-
>  drivers/gpu/nova-core/falcon/gsp.rs           |  4 +-
>  drivers/gpu/nova-core/falcon/sec2.rs          |  2 +-
>  drivers/gpu/nova-core/nova_core.rs            |  3 -
>  drivers/gpu/nova-core/regs.rs                 |  6 +-
>  .../gpu/nova-core => rust/kernel}/bitfield.rs | 27 ++++-----
>  rust/kernel/io.rs                             |  1 +
>  .../macros.rs => rust/kernel/io/register.rs   | 58 ++++++++++---------
>  rust/kernel/lib.rs                            |  1 +
>  9 files changed, 54 insertions(+), 50 deletions(-)
>  rename {drivers/gpu/nova-core => rust/kernel}/bitfield.rs (91%)
>  rename drivers/gpu/nova-core/regs/macros.rs => rust/kernel/io/register.rs (93%)
>
> diff --git a/drivers/gpu/nova-core/falcon.rs b/drivers/gpu/nova-core/falcon.rs
> index 37e6298195e4..a15fa98c8614 100644
> --- a/drivers/gpu/nova-core/falcon.rs
> +++ b/drivers/gpu/nova-core/falcon.rs
> @@ -6,6 +6,7 @@
>  use hal::FalconHal;
>  use kernel::device;
>  use kernel::dma::DmaAddress;
> +use kernel::io::register::RegisterBase;
>  use kernel::prelude::*;
>  use kernel::sync::aref::ARef;
>  use kernel::time::Delta;
> @@ -14,7 +15,6 @@
>  use crate::driver::Bar0;
>  use crate::gpu::Chipset;
>  use crate::regs;
> -use crate::regs::macros::RegisterBase;
>  use crate::util;
>  
>  pub(crate) mod gsp;
> diff --git a/drivers/gpu/nova-core/falcon/gsp.rs b/drivers/gpu/nova-core/falcon/gsp.rs
> index f17599cb49fa..cd4960e997c8 100644
> --- a/drivers/gpu/nova-core/falcon/gsp.rs
> +++ b/drivers/gpu/nova-core/falcon/gsp.rs
> @@ -1,9 +1,11 @@
>  // SPDX-License-Identifier: GPL-2.0
>  
> +use kernel::io::register::RegisterBase;
> +
>  use crate::{
>      driver::Bar0,
>      falcon::{Falcon, FalconEngine, PFalcon2Base, PFalconBase},
> -    regs::{self, macros::RegisterBase},
> +    regs::self,

`rustfmt` was not happy with this one:

--- a/drivers/gpu/nova-core/falcon/gsp.rs
+++ b/drivers/gpu/nova-core/falcon/gsp.rs
@@ -5,7 +5,7 @@
 use crate::{
     driver::Bar0,
     falcon::{Falcon, FalconEngine, PFalcon2Base, PFalconBase},
-    regs::self,
+    regs,
 };

No need to resend just for this though.