Re: [PATCH v8 2/9] dax/hmem: Factor HMEM registration into __hmem_register_device()

[Dave Jiang <dave.jiang@intel.com>]

On 3/22/26 12:53 PM, Smita Koralahalli wrote:
> Separate the CXL overlap check from the HMEM registration path and keep
> the platform-device setup in a dedicated __hmem_register_device().
> 
> This makes hmem_register_device() the policy entry point for deciding
> whether a range should be deferred to CXL, while __hmem_register_device()
> handles the HMEM registration flow.
> 
> No functional changes.
> 
> Signed-off-by: Smita Koralahalli <Smita.KoralahalliChannabasappa@amd.com>

Reviewed-by: Dave Jiang <dave.jiang@intel.com>

> ---
>  drivers/dax/hmem/hmem.c | 24 +++++++++++++++---------
>  1 file changed, 15 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/dax/hmem/hmem.c b/drivers/dax/hmem/hmem.c
> index 1cf7c2a0ee1c..a3d45032355c 100644
> --- a/drivers/dax/hmem/hmem.c
> +++ b/drivers/dax/hmem/hmem.c
> @@ -58,21 +58,14 @@ static void release_hmem(void *pdev)
>  	platform_device_unregister(pdev);
>  }
>  
> -static int hmem_register_device(struct device *host, int target_nid,
> -				const struct resource *res)
> +static int __hmem_register_device(struct device *host, int target_nid,
> +				  const struct resource *res)
>  {
>  	struct platform_device *pdev;
>  	struct memregion_info info;
>  	long id;
>  	int rc;
>  
> -	if (IS_ENABLED(CONFIG_CXL_REGION) &&
> -	    region_intersects(res->start, resource_size(res), IORESOURCE_MEM,
> -			      IORES_DESC_CXL) != REGION_DISJOINT) {
> -		dev_dbg(host, "deferring range to CXL: %pr\n", res);
> -		return 0;
> -	}
> -
>  	rc = region_intersects_soft_reserve(res->start, resource_size(res));
>  	if (rc != REGION_INTERSECTS)
>  		return 0;
> @@ -123,6 +116,19 @@ static int hmem_register_device(struct device *host, int target_nid,
>  	return rc;
>  }
>  
> +static int hmem_register_device(struct device *host, int target_nid,
> +				const struct resource *res)
> +{
> +	if (IS_ENABLED(CONFIG_CXL_REGION) &&
> +	    region_intersects(res->start, resource_size(res), IORESOURCE_MEM,
> +			      IORES_DESC_CXL) != REGION_DISJOINT) {
> +		dev_dbg(host, "deferring range to CXL: %pr\n", res);
> +		return 0;
> +	}
> +
> +	return __hmem_register_device(host, target_nid, res);
> +}
> +
>  static int dax_hmem_platform_probe(struct platform_device *pdev)
>  {
>  	return walk_hmem_resources(&pdev->dev, hmem_register_device);