[PATCHv2 3/3] nvme: Expose cntrltype and dctype through sysfs

[Greg KH]

On Thu, Feb 03, 2022 at 04:17:48PM -0500, Martin Belanger wrote:
> From: Martin Belanger <martin.belanger at dell.com>
> 
> TP8010 introduces the Discovery Controller Type attribute (dctype).
> 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. The dctype will
> only be displayed for discovery controllers.
> 
> Signed-off-by: Martin Belanger <martin.belanger at dell.com>
> ---
>  drivers/nvme/host/core.c | 45 ++++++++++++++++++++++++++++++++++++++++
>  drivers/nvme/host/nvme.h |  3 +++
>  include/linux/nvme.h     | 10 ++++++++-
>  3 files changed, 57 insertions(+), 1 deletion(-)

Where is the documentation for these new sysfs files?  That is required
to be in Documentation/ABI/

> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index b5e452aa3c0e..4e3db5ec3924 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -2990,6 +2990,9 @@ 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;
> @@ -3115,6 +3118,10 @@ int nvme_init_ctrl_finish(struct nvme_ctrl *ctrl)
>  			return ret;
>  	}
>  
> +	ret = device_update_groups(ctrl->device);
> +	if (ret)
> +		return ret;
> +
>  	ctrl->identified = true;
>  
>  	return 0;
> @@ -3523,6 +3530,40 @@ 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);
> +	const char *type[] = {
> +		[NVME_CTRL_IO] = "io\n",
> +		[NVME_CTRL_DISC] = "discovery\n",
> +		[NVME_CTRL_ADMIN] = "admin\n",
> +	};
> +
> +	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(cntrltype, S_IRUGO, nvme_ctrl_cntrltype_show, NULL);

DEVICE_ATTR_RO() please.

> +
> +static ssize_t nvme_ctrl_dctype_show(struct device *dev,
> +				     struct device_attribute *attr, char *buf)
> +{
> +	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
> +	const char *type[] = {
> +		[NVME_DCTYPE_NOT_REPORTED] = "none\n",
> +		[NVME_DCTYPE_DDC] = "ddc\n",
> +		[NVME_DCTYPE_CDC] = "cdc\n",
> +	};
> +
> +	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(dctype, S_IRUGO, nvme_ctrl_dctype_show, NULL);

Same here.

thanks,

greg k-h