[PATCH 1/4] nvme-fabrics: add discovery controller type

[Hannes Reinecke]

On 1/25/22 15:59, Martin Belanger wrote:
> From: Martin Belanger <martin.belanger at dell.com>
> 
> TP8010 introduces the Central Discovery Controller (CDC). To
> differentiate between a CDC and a DDC (Direct DC), the identify
> response now carries a DCTYPE (Discovery Controller Type) field.
> 
> Signed-off-by: Martin Belanger <martin.belanger at dell.com>
> ---
>   drivers/nvme/host/core.c |  3 +++
>   drivers/nvme/host/nvme.h |  2 ++
>   include/linux/nvme.h     | 10 +++++++++-
>   3 files changed, 14 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 4fc794d9c2f4..cd34b92e8e9d 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -2978,6 +2978,7 @@ static int nvme_init_identify(struct nvme_ctrl *ctrl)
>   	ctrl->kas = le16_to_cpu(id->kas);
>   	ctrl->max_namespaces = le32_to_cpu(id->mnan);
>   	ctrl->ctratt = le32_to_cpu(id->ctratt);
> +	ctrl->dctype = id->dctype;
>   
>   	if (id->rtd3e) {
>   		/* us -> s */
> @@ -3335,6 +3336,7 @@ nvme_show_int_function(numa_node);
>   nvme_show_int_function(queue_count);
>   nvme_show_int_function(sqsize);
>   nvme_show_int_function(kato);
> +nvme_show_int_function(dctype);
>   
>   static ssize_t nvme_sysfs_delete(struct device *dev,
>   				struct device_attribute *attr, const char *buf,
> @@ -3533,6 +3535,7 @@ static struct attribute *nvme_dev_attrs[] = {
>   	&dev_attr_reconnect_delay.attr,
>   	&dev_attr_fast_io_fail_tmo.attr,
>   	&dev_attr_kato.attr,
> +	&dev_attr_dctype.attr,
>   	NULL
>   };
>   
> diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
> index fe224016418e..f8b60f7346fd 100644
> --- a/drivers/nvme/host/nvme.h
> +++ b/drivers/nvme/host/nvme.h
> @@ -349,6 +349,8 @@ struct nvme_ctrl {
>   	unsigned long discard_page_busy;
>   
>   	struct nvme_fault_inject fault_inject;
> +
> +	enum nvme_dctype dctype;
>   };
>   
>   enum nvme_iopolicy {
> diff --git a/include/linux/nvme.h b/include/linux/nvme.h
> index 855dd9b3e84b..82567d493c51 100644
> --- a/include/linux/nvme.h
> +++ b/include/linux/nvme.h
> @@ -240,6 +240,12 @@ enum nvme_ctrl_attr {
>   	NVME_CTRL_ATTR_TBKAS		= (1 << 6),
>   };
>   
> +enum nvme_dctype {
> +	NVME_DCTYPE_NOT_REPORTED = 0,
> +	NVME_DCTYPE_DDC = 1,
> +	NVME_DCTYPE_CDC = 2,
> +};
> +
>   struct nvme_id_ctrl {
>   	__le16			vid;
>   	__le16			ssvid;
> @@ -320,7 +326,9 @@ struct nvme_id_ctrl {
>   	__le16			icdoff;
>   	__u8			ctrattr;
>   	__u8			msdbd;
> -	__u8			rsvd1804[244];
> +	__le16			ofcs;
> +	__u8			dctype;
> +	__u8			rsvd1807[241];
>   	struct nvme_id_power_state	psd[32];
>   	__u8			vs[1024];
>   };

Please decode the fields for the sysfs attribute; 'cdc' is far easier to 
understand than '2'.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		           Kernel Storage Architect
hare at suse.de			                  +49 911 74053 688
SUSE Software Solutions Germany GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), GF: Felix Imendörffer