[PATCH] ARM: efi: Simplify arch_efi_call_virt() macro by using typeof()

[Ard Biesheuvel]

On Tue, 28 Jun 2022 at 14:59, Sudeep Holla <sudeep.holla at arm.com> wrote:
>
> Currently, the arch_efi_call_virt() assumes all users of it will have
> defined a type 'efi_##f##_t' to make use of it. It is unnecessarily
> forcing the users to create a new typedef when __efi_rt_asm_wrapper()
> actually expects void pointer.
>
> Simplify the arch_efi_call_virt() macro by using typeof(p->f) which must
> be a pointer as required by __efi_rt_asm_wrapper() and eliminate the
> explicit need for efi_##f##_t type for every user of this macro.
>
> This change is done to align with implementations on other similar
> architectures.
>
> Cc: Ard Biesheuvel <ardb at kernel.org>
> Cc: Russell King <linux at armlinux.org.uk>
> Signed-off-by: Sudeep Holla <sudeep.holla at arm.com>
> ---
>  arch/arm/include/asm/efi.h | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> Hi,
>
> Reference for this change [1] and in particular[2]
>
> Regards,
> Sudeep
>
> [1] https://lore.kernel.org/r/20220628125346.693304-1-sudeep.holla@arm.com
> [2] https://lore.kernel.org/r/20220628125346.693304-3-sudeep.holla@arm.com/
>
> diff --git a/arch/arm/include/asm/efi.h b/arch/arm/include/asm/efi.h
> index 27218eabbf9a..d4a405c9b4b6 100644
> --- a/arch/arm/include/asm/efi.h
> +++ b/arch/arm/include/asm/efi.h
> @@ -26,8 +26,7 @@ int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md);
>
>  #define arch_efi_call_virt(p, f, args...)                              \
>  ({                                                                     \
> -       efi_##f##_t *__f;                                               \
> -       __f = p->f;                                                     \
> +       typeof(p->f) __f = p->f;                                        \
>         __f(args);                                                      \
>  })
>

I think this could simply be

#define arch_efi_call_virt(p, f, args...) ((p)->f(args))

no?