Re: [PATCHv3 2/2] nvme: Expose cntrltype and dctype through sysfs

[Chaitanya Kulkarni <chaitanyak@nvidia.com>]

> +static ssize_t cntrltype_show(struct device *dev,
> +			      struct device_attribute *attr, char *buf)
> +{
> +	static const char * const type[] = {

nit:- static cost char *const type[] ...

> +		[NVME_CTRL_IO] = "io\n",
> +		[NVME_CTRL_DISC] = "discovery\n",
> +		[NVME_CTRL_ADMIN] = "admin\n",
> +	};
> +	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
> +
> +	if (ctrl->cntrltype > NVME_CTRL_ADMIN || !type[ctrl->cntrltype])
> +		return sysfs_emit(buf, "reserved\n");
> +
> +	return sysfs_emit(buf, type[ctrl->cntrltype]);
> +}
> +static DEVICE_ATTR_RO(cntrltype);
> +
> +static ssize_t dctype_show(struct device *dev,
> +			   struct device_attribute *attr, char *buf)
> +{
> +	static const char * const type[] = {

nit:- static cost char *const typep[] ...

> +		[NVME_DCTYPE_NOT_REPORTED] = "none\n",
> +		[NVME_DCTYPE_DDC] = "ddc\n",
> +		[NVME_DCTYPE_CDC] = "cdc\n",
> +	};
> +	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
> +
> +	if (ctrl->dctype > NVME_DCTYPE_CDC || !type[ctrl->dctype])
> +		return sysfs_emit(buf, "reserved\n");
> +
> +	return sysfs_emit(buf, type[ctrl->dctype]);
> +}
> +static DEVICE_ATTR_RO(dctype);
> +
>   static struct attribute *nvme_dev_attrs[] = {
>   	&dev_attr_reset_controller.attr,
>   	&dev_attr_rescan_controller.attr,
> @@ -3544,6 +3581,8 @@ 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
>   };
>   
> 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..21e92e97ca88 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];
>   };
>