Re: [PATCH v3] rust: helpers: Add dma_alloc_attrs() and dma_free_attrs()

[Danilo Krummrich <dakr@kernel.org>]

On Sat, Apr 12, 2025 at 09:05:06AM +0900, FUJITA Tomonori wrote:
> Add dma_alloc_attrs() and dma_free_attrs() helpers to fix a build
> error when CONFIG_HAS_DMA is not enabled.
> 
> Note that when CONFIG_HAS_DMA is enabled, dma_alloc_attrs() and
> dma_free_attrs() are included in both bindings_generated.rs and
> bindings_helpers_generated.rs. The former takes precedence so behavior
> remains unchanged in that case.
> 
> This fixes the following build error on UML:
> 
> error[E0425]: cannot find function `dma_alloc_attrs` in crate `bindings`
>      --> rust/kernel/dma.rs:171:23
>       |
> 171   |               bindings::dma_alloc_attrs(
>       |                         ^^^^^^^^^^^^^^^ help: a function with a similar name exists: `dma_alloc_pages`
>       |
>      ::: /home/fujita/build/um/rust/bindings/bindings_generated.rs:44568:5
>       |
> 44568 | /     pub fn dma_alloc_pages(
> 44569 | |         dev: *mut device,
> 44570 | |         size: usize,
> 44571 | |         dma_handle: *mut dma_addr_t,
> 44572 | |         dir: dma_data_direction,
> 44573 | |         gfp: gfp_t,
> 44574 | |     ) -> *mut page;
>       | |___________________- similarly named function `dma_alloc_pages` defined here
> 
> error[E0425]: cannot find function `dma_free_attrs` in crate `bindings`
>      --> rust/kernel/dma.rs:293:23
>       |
> 293   |               bindings::dma_free_attrs(
>       |                         ^^^^^^^^^^^^^^ help: a function with a similar name exists: `dma_free_pages`
>       |
>      ::: /home/fujita/build/um/rust/bindings/bindings_generated.rs:44577:5
>       |
> 44577 | /     pub fn dma_free_pages(
> 44578 | |         dev: *mut device,
> 44579 | |         size: usize,
> 44580 | |         page: *mut page,
> 44581 | |         dma_handle: dma_addr_t,
> 44582 | |         dir: dma_data_direction,
> 44583 | |     );
>       | |______- similarly named function `dma_free_pages` defined here
> 
> Fixes: ad2907b4e308 ("rust: add dma coherent allocator abstraction")
> Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>

Acked-by: Danilo Krummrich <dakr@kernel.org>