On Thu, Feb 27, 2025 at 10:38:08PM +0000, 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/core.h | 2 ++
> drivers/cxl/core/features.c | 20 ++++++++++++++++++++
> 2 files changed, 22 insertions(+)
>
> diff --git a/drivers/cxl/core/core.h b/drivers/cxl/core/core.h
> index 3d3b00835446..6c83f6f18122 100644
> --- a/drivers/cxl/core/core.h
> +++ b/drivers/cxl/core/core.h
> @@ -120,6 +120,8 @@ int cxl_port_get_switch_dport_bandwidth(struct cxl_port *port,
> int cxl_gpf_port_setup(struct device *dport_dev, struct cxl_port *port);
>
> #ifdef CONFIG_CXL_FEATURES
> +struct cxl_feat_entry *cxl_get_feature_entry(struct cxl_dev_state *cxlds,
> + 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,
> diff --git a/drivers/cxl/core/features.c b/drivers/cxl/core/features.c
> index 048ba4fc3538..c822fb4a8c33 100644
> --- a/drivers/cxl/core/features.c
> +++ b/drivers/cxl/core/features.c
> @@ -203,6 +203,26 @@ int devm_cxl_setup_features(struct cxl_dev_state *cxlds)
> }
> EXPORT_SYMBOL_NS_GPL(devm_cxl_setup_features, "CXL");
>
> +struct cxl_feat_entry *cxl_get_feature_entry(struct cxl_dev_state *cxlds,
> + const uuid_t *feat_uuid)
> +{
> + struct cxl_features_state *cxlfs = to_cxlfs(cxlds);
> + 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->ent;
Do we need some NULL checking here on cxlfs, entries
> + for (count = 0; count < cxlfs->entries->num_features; count++, feat_entry++) {
Was num_features previously validated?
> + if (uuid_equal(&feat_entry->uuid, feat_uuid))
> + return feat_entry;
> + }
> +
> + return ERR_PTR(-ENOENT);
Why not just return NULL?
> +}
> +
> 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,
> --
> 2.43.0
>
