On Wed, Jan 27, 2021 at 12:19:22PM +0800, Orson Zhai wrote:
> In some circumstances, multiple __ATTR_RO attributes need to be assigned
> with a single show function.
>
> Add this macro to make life easier with simple code.
>
> Signed-off-by: Orson Zhai <orsonzhai@xxxxxxxxx>
> ---
> Documentation/filesystems/sysfs.rst | 2 ++
> include/linux/sysfs.h | 5 +++++
> 2 files changed, 7 insertions(+)
>
> diff --git a/Documentation/filesystems/sysfs.rst b/Documentation/filesystems/sysfs.rst
> index 004d490..0e2274a 100644
> --- a/Documentation/filesystems/sysfs.rst
> +++ b/Documentation/filesystems/sysfs.rst
> @@ -141,6 +141,8 @@ __ATTR_RO_MODE(name, mode):
> fore more restrictive RO access currently
> only use case is the EFI System Resource Table
> (see drivers/firmware/efi/esrt.c)
> +__ATTR_RO_SHOW(name, show):
> + assumes default mode 0444 with specified show.
> __ATTR_RW(name):
> assumes default name_show, name_store and setting
> mode to 0644.
> diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
> index 2caa34c..c851592 100644
> --- a/include/linux/sysfs.h
> +++ b/include/linux/sysfs.h
> @@ -117,6 +117,11 @@ struct attribute_group {
> .show = _name##_show, \
> }
>
> +#define __ATTR_RO_SHOW(_name, _show) { \
> + .attr = { .name = __stringify(_name), .mode = 0444 }, \
> + .show = _show, \
> +}
Do you have a real user for this? Using "raw" kobject attributes is
rare and should not be used often, so who needs this?
thanks,
greg k-h
