Re: [PATCH 11/23] libnvdimm/labels: Introduce CXL labels

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Mon, 9 Aug 2021 15:28:46 -0700
Dan Williams <dan.j.williams@intel.com> wrote:

> Now that all of use sites of label data have been converted to nsl_*
> helpers, introduce the CXL label format. The ->cxl flag in
> nvdimm_drvdata indicates the label format the device expects. A
> follow-on patch allows a bus provider to select the label style.
> 
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>

A few trivial things inline. Nothing that actually 'needs' changing though.
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> index e6e77691dbec..71ffde56fac0 100644
> --- a/drivers/nvdimm/label.h
> +++ b/drivers/nvdimm/label.h
> @@ -64,40 +64,77 @@ struct nd_namespace_index {
>  	u8 free[];
>  };
>  
> -/**
> - * struct nd_namespace_label - namespace superblock
> - * @uuid: UUID per RFC 4122
> - * @name: optional name (NULL-terminated)
> - * @flags: see NSLABEL_FLAG_*
> - * @nlabel: num labels to describe this ns
> - * @position: labels position in set
> - * @isetcookie: interleave set cookie
> - * @lbasize: LBA size in bytes or 0 for pmem
> - * @dpa: DPA of NVM range on this DIMM
> - * @rawsize: size of namespace
> - * @slot: slot of this label in label area
> - * @unused: must be zero
> - */
>  struct nd_namespace_label {
> +	union {
Cross reference might be a nice thing to include?
Table 212 I think...
> +		struct nvdimm_cxl_label {
> +			uuid_t type;
> +			uuid_t uuid;
> +			u8 name[NSLABEL_NAME_LEN];
> +			__le32 flags;
> +			__le16 nlabel;

Perhaps call out nlabel is nrange in the spec?

> +			__le16 position;
> +			__le64 dpa;
> +			__le64 rawsize;
> +			__le32 slot;
> +			__le32 align;
> +			uuid_t region_uuid;
> +			uuid_t abstraction_uuid;
> +			__le16 lbasize;
> +			u8 reserved[0x56];
> +			__le64 checksum;
> +		} cxl;
> +		/**
> +		 * struct nvdimm_efi_label - namespace superblock
> +		 * @uuid: UUID per RFC 4122
> +		 * @name: optional name (NULL-terminated)
> +		 * @flags: see NSLABEL_FLAG_*
> +		 * @nlabel: num labels to describe this ns
> +		 * @position: labels position in set
> +		 * @isetcookie: interleave set cookie
> +		 * @lbasize: LBA size in bytes or 0 for pmem
> +		 * @dpa: DPA of NVM range on this DIMM
> +		 * @rawsize: size of namespace
> +		 * @slot: slot of this label in label area
> +		 * @unused: must be zero
> +		 */
> +		struct nvdimm_efi_label {
> +			uuid_t uuid;
> +			u8 name[NSLABEL_NAME_LEN];
> +			__le32 flags;
> +			__le16 nlabel;
> +			__le16 position;
> +			__le64 isetcookie;
> +			__le64 lbasize;
> +			__le64 dpa;
> +			__le64 rawsize;
> +			__le32 slot;
> +			/*
> +			 * Accessing fields past this point should be
> +			 * gated by a efi_namespace_label_has() check.
> +			 */
> +			u8 align;
> +			u8 reserved[3];
> +			guid_t type_guid;
> +			guid_t abstraction_guid;
> +			u8 reserved2[88];
> +			__le64 checksum;
> +		} efi;
> +	};
> +};
> +
> +struct cxl_region_label {

Perhaps separate this out to another patch so the diff ends up less confusing?

> +	uuid_t type;
>  	uuid_t uuid;
> -	u8 name[NSLABEL_NAME_LEN];
>  	__le32 flags;
>  	__le16 nlabel;
>  	__le16 position;
> -	__le64 isetcookie;
> -	__le64 lbasize;
>  	__le64 dpa;
>  	__le64 rawsize;
> +	__le64 hpa;
>  	__le32 slot;
> -	/*
> -	 * Accessing fields past this point should be gated by a
> -	 * namespace_label_has() check.
> -	 */
> -	u8 align;
> -	u8 reserved[3];
> -	guid_t type_guid;
> -	guid_t abstraction_guid;
> -	u8 reserved2[88];
> +	__le32 ig;
> +	__le32 align;
> +	u8 reserved[0xac];
>  	__le64 checksum;
>  };