Re: [PATCH v19 07/15] cxl: Add helper function to retrieve a feature entry

[Dave Jiang]

On 2/7/25 7:44 AM, shiju.jose@xxxxxxxxxx wrote:
> From: Shiju Jose <shiju.jose@xxxxxxxxxx>
> 
> Add helper function to retrieve a feature entry from the supported
> features list, if supported.
> 
> Signed-off-by: Shiju Jose <shiju.jose@xxxxxxxxxx>
> ---
>  drivers/cxl/core/features.c | 21 +++++++++++++++++++++
>  include/cxl/features.h      |  2 ++
>  2 files changed, 23 insertions(+)
> 
> diff --git a/drivers/cxl/core/features.c b/drivers/cxl/core/features.c
> index 5f64185a5c7a..bf175e69cda1 100644
> --- a/drivers/cxl/core/features.c
> +++ b/drivers/cxl/core/features.c
> @@ -43,6 +43,27 @@ bool is_cxl_feature_exclusive(struct cxl_feat_entry *entry)
>  }
>  EXPORT_SYMBOL_NS_GPL(is_cxl_feature_exclusive, "CXL");
>  
> +struct cxl_feat_entry *cxl_get_feature_entry(struct cxl_memdev *cxlmd,
> +					     const uuid_t *feat_uuid)
> +{
> +	struct cxl_features_state *cxlfs = cxlmd->cxlfs;
> +	struct cxl_feat_entry *feat_entry;
> +	int count;
> +
> +	/*
> +	 * Retrieve the feature entry from the supported features list,
> +	 * if the feature is supported.
> +	 */
> +	feat_entry = cxlfs->entries;
> +	for (count = 0; count < cxlfs->num_features; count++, feat_entry++) {
> +		if (uuid_equal(&feat_entry->uuid, feat_uuid))
> +			return feat_entry;
> +	}
> +
> +	return ERR_PTR(-ENOENT);
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_get_feature_entry, "CXL");

You probably don't need this if the memfeature code are in CXL core. 

DJ

> +
>  size_t cxl_get_feature(struct cxl_mailbox *cxl_mbox, const uuid_t *feat_uuid,
>  		       enum cxl_get_feat_selection selection,
>  		       void *feat_out, size_t feat_out_size, u16 offset,
> diff --git a/include/cxl/features.h b/include/cxl/features.h
> index e52d0573f504..563d966beee5 100644
> --- a/include/cxl/features.h
> +++ b/include/cxl/features.h
> @@ -68,6 +68,8 @@ struct cxl_features_state {
>  };
>  
>  struct cxl_mailbox;
> +struct cxl_feat_entry *cxl_get_feature_entry(struct cxl_memdev *cxlmd,
> +					     const uuid_t *feat_uuid);
>  size_t cxl_get_feature(struct cxl_mailbox *cxl_mbox, const uuid_t *feat_uuid,
>  		       enum cxl_get_feat_selection selection,
>  		       void *feat_out, size_t feat_out_size, u16 offset,