Re: [PATCH 1/7] debugfs: Add debugfs_create_xul() for hexadecimal unsigned long

[Joe Perches]

On Mon, 2019-10-21 at 16:37 +0200, Geert Uytterhoeven wrote:
> The existing debugfs_create_ulong() function supports objects of
> type "unsigned long", which are 32-bit or 64-bit depending on the
> platform, in decimal form.  To format objects in hexadecimal, various
> debugfs_create_x*() functions exist, but all of them take fixed-size
> types.
> 
> Add a debugfs helper for "unsigned long" objects in hexadecimal format.
> This avoids the need for users to open-code the same, or introduce
> bugs when casting the value pointer to "u32 *" or "u64 *" to call
> debugfs_create_x{32,64}().
[]
> diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
[]
> @@ -356,4 +356,14 @@ static inline ssize_t debugfs_write_file_bool(struct file *file,
>  
>  #endif
>  
> +static inline void debugfs_create_xul(const char *name, umode_t mode,
> +				      struct dentry *parent,
> +				      unsigned long *value)
> +{
> +	if (sizeof(*value) == sizeof(u32))
> +		debugfs_create_x32(name, mode, parent, (u32 *)value);
> +	else
> +		debugfs_create_x64(name, mode, parent, (u64 *)value);

trivia: the casts are unnecessary.

This might be more sensible using #ifdef

static inline void debugfs_create_xul(const char *name, umode_t mode,
				      struct dentry *parent,
				      unsigned long *value)
{
#if BITS_PER_LONG == 64
	debugfs_create_x64(name, mode, parent, value);
#else
	debugfs_create_x32(name, mode, parent, value);
#endif
}