Re: [PATCH v4 05/15] cxl/mbox: Add SET_FEATURE mailbox command

[Dan Williams <dan.j.williams@intel.com>]

Dave Jiang wrote:
> From: Shiju Jose <shiju.jose@huawei.com>
> 
> Add support for SET_FEATURE mailbox command.
> 
> CXL spec r3.2 section 8.2.9.6 describes optional device specific features.
> CXL devices supports features with changeable attributes.
> The settings of a feature can be optionally modified using Set Feature
> command.
> CXL spec r3.2 section 8.2.9.6.3 describes Set Feature command.
> 
> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> Signed-off-by: Shiju Jose <shiju.jose@huawei.com>
> Signed-off-by: Dave Jiang <dave.jiang@intel.com>
> ---
>  drivers/cxl/core/features.c | 81 +++++++++++++++++++++++++++++++++++++
>  include/cxl/features.h      | 42 +++++++++++++++++++
>  2 files changed, 123 insertions(+)
> 
> diff --git a/drivers/cxl/core/features.c b/drivers/cxl/core/features.c
> index 262e4b1cb7fc..d337224158fa 100644
> --- a/drivers/cxl/core/features.c
> +++ b/drivers/cxl/core/features.c
> @@ -227,3 +227,84 @@ size_t cxl_get_feature(struct cxl_mailbox *cxl_mbox, const uuid_t *feat_uuid,
>  	return data_rcvd_size;
>  }
>  EXPORT_SYMBOL_NS_GPL(cxl_get_feature, "CXL");
> +
> +/*
> + * FEAT_DATA_MIN_PAYLOAD_SIZE - min extra number of bytes should be
> + * available in the mailbox for storing the actual feature data so that
> + * the feature data transfer would work as expected.
> + */
> +#define FEAT_DATA_MIN_PAYLOAD_SIZE 10
> +int cxl_set_feature(struct cxl_mailbox *cxl_mbox,
> +		    const uuid_t *feat_uuid, u8 feat_version,
> +		    void *feat_data, size_t feat_data_size,
> +		    u32 feat_flag, u16 offset, u16 *return_code)
> +{
> +	struct cxl_memdev_set_feat_pi {
> +		struct cxl_mbox_set_feat_hdr hdr;
> +		u8 feat_data[];
> +	}  __packed;
> +	size_t data_in_size, data_sent_size = 0;
> +	struct cxl_mbox_cmd mbox_cmd;
> +	size_t hdr_size;
> +	int rc = 0;
> +
> +	if (return_code)
> +		*return_code = CXL_MBOX_CMD_RC_INPUT;
> +
> +	struct cxl_memdev_set_feat_pi *pi __free(kfree) =
> +			kzalloc(cxl_mbox->payload_size, GFP_KERNEL);

Missing NULL check on @pi?

[..]
> +}
> +EXPORT_SYMBOL_NS_GPL(cxl_set_feature, "CXL");

Same, "no need to export" comment as Get Feature.

Minor things to fixup, so feel free to add:

Reviewed-by: Dan Williams <dan.j.williams@intel.com>