[PATCH 2/2] nvme: Expose cntrltype and dctype through sysfs.

[Hannes Reinecke]

On 2/2/22 22:34, Martin Belanger wrote:
> From: Martin Belanger <martin.belanger at dell.com>
> 
> TP8010 introduces the Discovery Controller Type (dctype)
> attribute. The dctype is returned in the response to the
> Identify command. This patch exposes the dctype through
> the sysfs. Since the dctype depends on the Controller
> Type (cntrltype), another attribute of the Identify
> response, the patch also exposes the cntrltype as well.
> 
> Signed-off-by: Martin Belanger <martin.belanger at dell.com>
> ---
>   drivers/nvme/host/core.c | 35 +++++++++++++++++++++++++++++++++++
>   drivers/nvme/host/nvme.h |  3 +++
>   include/linux/nvme.h     | 10 +++++++++-
>   3 files changed, 47 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 872c389dc6d3..c65d44fb65c4 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -2992,6 +2992,9 @@ static int nvme_init_identify(struct nvme_ctrl *ctrl)
>   	ctrl->max_namespaces = le32_to_cpu(id->mnan);
>   	ctrl->ctratt = le32_to_cpu(id->ctratt);
>   
> +	ctrl->cntrltype = id->cntrltype;
> +	ctrl->dctype = id->dctype;
> +
>   	if (id->rtd3e) {
>   		/* us -> s */
>   		u32 transition_time = le32_to_cpu(id->rtd3e) / USEC_PER_SEC;
> @@ -3525,6 +3528,34 @@ static ssize_t nvme_ctrl_fast_io_fail_tmo_store(struct device *dev,
>   static DEVICE_ATTR(fast_io_fail_tmo, S_IRUGO | S_IWUSR,
>   	nvme_ctrl_fast_io_fail_tmo_show, nvme_ctrl_fast_io_fail_tmo_store);
>   
> +static ssize_t nvme_ctrl_cntrltype_show(struct device *dev,
> +				     struct device_attribute *attr, char *buf)
> +{
> +	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
> +
> +	switch (ctrl->cntrltype) {
> +	case NVME_CTRL_IO:	return sysfs_emit(buf, "io\n");
> +	case NVME_CTRL_DISC:	return sysfs_emit(buf, "disc\n");

'discovery', please. 'disc' is misleading here.

> +	case NVME_CTRL_ADMIN:	return sysfs_emit(buf, "admin\n");
> +	default:		return sysfs_emit(buf, "reserved\n");
> +	}
> +}
> +static DEVICE_ATTR(cntrltype, S_IRUGO, nvme_ctrl_cntrltype_show, NULL);
> +
> +static ssize_t nvme_ctrl_dctype_show(struct device *dev,
> +				     struct device_attribute *attr, char *buf)
> +{
> +	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
> +
> +	switch (ctrl->dctype) {
> +	case NVME_DCTYPE_NOT_REPORTED:	return sysfs_emit(buf, "nr\n");

Please use 'none' here; 'nr' is ambiguous ('Number'?)

> +	case NVME_DCTYPE_DDC:		return sysfs_emit(buf, "ddc\n");
> +	case NVME_DCTYPE_CDC:		return sysfs_emit(buf, "cdc\n");
> +	default:			return sysfs_emit(buf, "reserved\n");
> +	}
> +}
> +static DEVICE_ATTR(dctype, S_IRUGO, nvme_ctrl_dctype_show, NULL);
> +
>   static struct attribute *nvme_dev_attrs[] = {
>   	&dev_attr_reset_controller.attr,
>   	&dev_attr_rescan_controller.attr,
> @@ -3546,6 +3577,8 @@ static struct attribute *nvme_dev_attrs[] = {
>   	&dev_attr_reconnect_delay.attr,
>   	&dev_attr_fast_io_fail_tmo.attr,
>   	&dev_attr_kato.attr,
> +	&dev_attr_cntrltype.attr,
> +	&dev_attr_dctype.attr,
>   	NULL
>   };
>   
> @@ -3569,6 +3602,8 @@ static umode_t nvme_dev_attrs_are_visible(struct kobject *kobj,
>   		return 0;
>   	if (a == &dev_attr_fast_io_fail_tmo.attr && !ctrl->opts)
>   		return 0;
> +	if (a == &dev_attr_dctype.attr && ctrl->cntrltype == NVME_CTRL_DISC)
> +		return 0;
>   
>   	return a->mode;
>   }
> diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
> index a162f6c6da6e..e30626c00791 100644
> --- a/drivers/nvme/host/nvme.h
> +++ b/drivers/nvme/host/nvme.h
> @@ -349,6 +349,9 @@ struct nvme_ctrl {
>   	unsigned long discard_page_busy;
>   
>   	struct nvme_fault_inject fault_inject;
> +
> +	enum nvme_ctrl_type cntrltype;
> +	enum nvme_dctype dctype;
>   };
>   
>   enum nvme_iopolicy {
> diff --git a/include/linux/nvme.h b/include/linux/nvme.h
> index 855dd9b3e84b..af1494d83a52 100644
> --- a/include/linux/nvme.h
> +++ b/include/linux/nvme.h
> @@ -43,6 +43,12 @@ enum nvme_ctrl_type {
>   	NVME_CTRL_ADMIN	= 3,		/* Administrative controller */
>   };
>   
> +enum nvme_dctype {
> +	NVME_DCTYPE_NOT_REPORTED = 0,
> +	NVME_DCTYPE_DDC = 1,		/* Direct Discovery Controller */
> +	NVME_DCTYPE_CDC = 2,		/* Central Discovery Controller */
> +};
> +
>   /* Address Family codes for Discovery Log Page entry ADRFAM field */
>   enum {
>   	NVMF_ADDR_FAMILY_PCI	= 0,	/* PCIe */
> @@ -320,7 +326,9 @@ struct nvme_id_ctrl {
>   	__le16			icdoff;
>   	__u8			ctrattr;
>   	__u8			msdbd;
> -	__u8			rsvd1804[244];
> +	__u8			rsvd1804[2];
> +	__u8			dctype;
> +	__u8			rsvd1807[241];
>   	struct nvme_id_power_state	psd[32];
>   	__u8			vs[1024];
>   };

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare at suse.de                              +49 911 74053 688
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