[RFC PATCH 2/2] nvme-core: use macro defination to define dev attr

[Hannes Reinecke]

On 4/27/23 10:02, Chaitanya Kulkarni wrote:
> Insated of duplicating the code for dhchap_secret & dhchap_ctrl_secret,
> define a macro to register device attribute to create device attribute
> that will also define store and show helpers.
> 
> Signed-off-by: Chaitanya Kulkarni <kch at nvidia.com>
> ---
>   drivers/nvme/host/core.c | 71 +++++++++++++++-------------------------
>   1 file changed, 27 insertions(+), 44 deletions(-)
> 
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 171ae1f2197a..f619158ea2fc 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -3780,17 +3780,6 @@ static DEVICE_ATTR_RO(dctype);
>   
>   #ifdef CONFIG_NVME_AUTH
>   
> -static ssize_t nvme_ctrl_dhchap_secret_show(struct device *dev,
> -		struct device_attribute *attr, char *buf)
> -{
> -	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
> -	struct nvmf_ctrl_options *opts = ctrl->opts;
> -
> -	if (!opts->dhchap_secret)
> -		return sysfs_emit(buf, "none\n");
> -	return sysfs_emit(buf, "%s\n", opts->dhchap_secret);
> -}
> -
>   static ssize_t nvme_dhchap_secret_store_common(struct nvme_ctrl *ctrl,
>   		char **dhchap_secret, struct nvme_dhchap_key **orig_key,
>   		const char *buf, size_t count)
> @@ -3833,40 +3822,34 @@ static ssize_t nvme_dhchap_secret_store_common(struct nvme_ctrl *ctrl,
>   	return count;
>   }
>   
> -static ssize_t nvme_ctrl_dhchap_secret_store(struct device *dev,
> -		struct device_attribute *attr, const char *buf, size_t count)
> -{
> -	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
> -
> -	return nvme_dhchap_secret_store_common(ctrl, &ctrl->opts->dhchap_secret,
> -			&ctrl->host_key, buf, count);
> -}
> -
> -static DEVICE_ATTR(dhchap_secret, S_IRUGO | S_IWUSR,
> -	nvme_ctrl_dhchap_secret_show, nvme_ctrl_dhchap_secret_store);
> -
> -static ssize_t nvme_ctrl_dhchap_ctrl_secret_show(struct device *dev,
> -		struct device_attribute *attr, char *buf)
> -{
> -	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
> -	struct nvmf_ctrl_options *opts = ctrl->opts;
> -
> -	if (!opts->dhchap_ctrl_secret)
> -		return sysfs_emit(buf, "none\n");
> -	return sysfs_emit(buf, "%s\n", opts->dhchap_ctrl_secret);
> -}
> -
> -static ssize_t nvme_ctrl_dhchap_ctrl_secret_store(struct device *dev,
> -		struct device_attribute *attr, const char *buf, size_t count)
> -{
> -	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
> +#define NVME_AUTH_DEVICE_ATTR(NAME)					\
> +static ssize_t nvme_ctrl_##NAME##_show(struct device *dev,		\
> +		struct device_attribute *attr, char *buf)		\
> +{									\
> +	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);			\
> +	struct nvmf_ctrl_options *opts = ctrl->opts;			\
> +									\
> +	if (!opts->NAME)						\
> +		return sysfs_emit(buf, "none\n");			\
> +	return sysfs_emit(buf, "%s\n", opts->NAME);			\
> +}									\
> +									\
> +static ssize_t nvme_ctrl_##NAME##_store(struct device *dev,		\
> +		struct device_attribute *attr, const char *buf, 	\
> +		size_t count)						\
> +{									\
> +	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);			\
> +									\
> +	return nvme_dhchap_secret_store_common(ctrl,			\
> +			&ctrl->opts->NAME,				\
> +			&ctrl->host_key, buf, count);			\
> +}									\
> +									\
> +static DEVICE_ATTR(NAME, S_IRUGO | S_IWUSR,				\
> +	nvme_ctrl_##NAME##_show, nvme_ctrl_##NAME##_store);		\
>   
> -	return nvme_dhchap_secret_store_common(ctrl,
> -			&ctrl->opts->dhchap_ctrl_secret, &ctrl->ctrl_key, buf,
> -			count);
> -}
> -static DEVICE_ATTR(dhchap_ctrl_secret, S_IRUGO | S_IWUSR,
> -	nvme_ctrl_dhchap_ctrl_secret_show, nvme_ctrl_dhchap_ctrl_secret_store);
> +NVME_AUTH_DEVICE_ATTR(dhchap_secret);
> +NVME_AUTH_DEVICE_ATTR(dhchap_ctrl_secret);
>   #endif
>   
>   static struct attribute *nvme_dev_attrs[] = {

In principle ok, but obviously depends on the discussion on the first patch.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
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