Re: [PATCH v22 13/25] cxl: Export functions for unwinding cxl by accelerators

[Jonathan Cameron <jonathan.cameron@huawei.com>]

On Fri, 5 Dec 2025 11:52:36 +0000
<alejandro.lucero-palau@amd.com> wrote:

> From: Alejandro Lucero <alucerop@amd.com>
> 
> Add unregister_region() and cxl_decoder_detach() to the accelerator
> driver API for a clean exit.
> 
> Signed-off-by: Alejandro Lucero <alucerop@amd.com>
In general seems fine but comment on type safety inline.

Jonathan

> ---
>  drivers/cxl/core/core.h   | 5 -----
>  drivers/cxl/core/region.c | 4 +++-
>  include/cxl/cxl.h         | 9 +++++++++
>  3 files changed, 12 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
> index 1c1726856139..9a6775845afe 100644
> --- a/drivers/cxl/core/core.h
> +++ b/drivers/cxl/core/core.h
> @@ -15,11 +15,6 @@ extern const struct device_type cxl_pmu_type;
>  
>  extern struct attribute_group cxl_base_attribute_group;
>  
> -enum cxl_detach_mode {
> -	DETACH_ONLY,
> -	DETACH_INVALIDATE,
> -};
> -
>  #ifdef CONFIG_CXL_REGION
>  extern struct device_attribute dev_attr_create_pmem_region;
>  extern struct device_attribute dev_attr_create_ram_region;
> diff --git a/drivers/cxl/core/region.c b/drivers/cxl/core/region.c
> index 8166a402373e..104caa33b7bb 100644
> --- a/drivers/cxl/core/region.c
> +++ b/drivers/cxl/core/region.c
> @@ -2199,6 +2199,7 @@ int cxl_decoder_detach(struct cxl_region *cxlr,
>  	}
>  	return 0;
>  }
> +EXPORT_SYMBOL_NS_GPL(cxl_decoder_detach, "CXL");
>  
>  static int __attach_target(struct cxl_region *cxlr,
>  			   struct cxl_endpoint_decoder *cxled, int pos,
> @@ -2393,7 +2394,7 @@ static struct cxl_region *to_cxl_region(struct device *dev)
>  	return container_of(dev, struct cxl_region, dev);
>  }
>  
> -static void unregister_region(void *_cxlr)
> +void unregister_region(void *_cxlr)
>  {
>  	struct cxl_region *cxlr = _cxlr;
>  	struct cxl_region_params *p = &cxlr->params;
> @@ -2412,6 +2413,7 @@ static void unregister_region(void *_cxlr)
>  	cxl_region_iomem_release(cxlr);
>  	put_device(&cxlr->dev);
>  }
> +EXPORT_SYMBOL_NS_GPL(unregister_region, "CXL");
>  
>  static struct lock_class_key cxl_region_key;
>  
> diff --git a/include/cxl/cxl.h b/include/cxl/cxl.h
> index f02dd817b40f..b8683c75dfde 100644
> --- a/include/cxl/cxl.h
> +++ b/include/cxl/cxl.h
> @@ -255,4 +255,13 @@ struct cxl_endpoint_decoder *cxl_get_committed_decoder(struct cxl_memdev *cxlmd,
>  						       struct cxl_region **cxlr);
>  struct range;
>  int cxl_get_region_range(struct cxl_region *region, struct range *range);
> +enum cxl_detach_mode {
> +	DETACH_ONLY,
> +	DETACH_INVALIDATE,
> +};
> +
> +int cxl_decoder_detach(struct cxl_region *cxlr,
> +		       struct cxl_endpoint_decoder *cxled, int pos,
> +		       enum cxl_detach_mode mode);
> +void unregister_region(void *_cxlr);

I'd wrap this for an exposed interface that isn't going to be used
as a devm callback so we can make it type safe.  Maybe making the
existing devm callback the one doing wrapping is cleanest route.


>  #endif /* __CXL_CXL_H__ */