Re: [PATCH 1/2] Create UV efi_call macros

Ingo Molnar
2016-05-12T08:17:39Z

* Ard Biesheuvel <ard.biesheuvel-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> wrote:

> On 12 May 2016 at 08:46, Ingo Molnar <mingo-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org> wrote:
> >
> > * Alex Thorlton <athorlton-sJ/iWh9BUns@public.gmane.org> wrote:
> >
> >> +#define efi_call_virt(f, args...) \
> >> +({ \
> >> + efi_status_t __s; \
> >> + unsigned long flags; \
> >> + arch_efi_call_virt_setup(); \
> >> + local_save_flags(flags); \
> >> + __s = arch_efi_call_virt(f, args); \
> >> + efi_call_virt_check_flags(flags, __stringify(f)); \
> >> + arch_efi_call_virt_teardown(); \
> >> + __s; \
> >> +})
> >> +
> >> +#define __efi_call_virt(f, args...) \
> >> +({ \
> >> + unsigned long flags; \
> >> + arch_efi_call_virt_setup(); \
> >> + local_save_flags(flags); \
> >> + arch_efi_call_virt(f, args); \
> >> + efi_call_virt_check_flags(flags, __stringify(f)); \
> >> + arch_efi_call_virt_teardown(); \
> >> +})
> >> +
> >> +#define uv_call_virt(f, args...) \
> >> +({ \
> >> + efi_status_t __s; \
> >> + unsigned long flags; \
> >> + arch_efi_call_virt_setup(); \
> >> + local_save_flags(flags); \
> >> + __s = uv_efi_call_virt(f, args); \
> >> + efi_call_virt_check_flags(flags, __stringify(f)); \
> >> + arch_efi_call_virt_teardown(); \
> >> + __s; \
> >> +})
> >
> > Btw., a very (very!) small stylistic nit that caught my eyes, and I realize that
> > you just moved code, but could you please improve these macros a bit and make it
> > look like regular kernel code? I.e. something like:
> >
> > #define efi_call_virt(f, args...) \
> > ({ \
> > efi_status_t __s; \
> > unsigned long flags; \
> > \
> > arch_efi_call_virt_setup(); \
> > \
> > local_save_flags(flags); \
> > __s = arch_efi_call_virt(f, args); \
> > efi_call_virt_check_flags(flags, __stringify(f)); \
> > arch_efi_call_virt_teardown(); \
> > \
> > __s; \
> > })
> >
> > This delineates the various blocks of code: variables, setup, the saving/calling
> > block plus the return code.
> >
> > (Assuming the EFI folks like the whole approach.)
> >
>
> Fine by me, although having a newline after arch_efi_call_virt_setup()
> but not before arch_efi_call_virt_teardown() seems rather arbitrary

It's an oversight! :-)

#define efi_call_virt(f, args...) \
({ \
efi_status_t __s; \
unsigned long flags; \
\
arch_efi_call_virt_setup(); \
\
local_save_flags(flags); \
__s = arch_efi_call_virt(f, args); \
efi_call_virt_check_flags(flags, __stringify(f)); \
\
arch_efi_call_virt_teardown(); \
\
__s; \
})

But if it's too segmented this is fine too:

#define efi_call_virt(f, args...) \
({ \
efi_status_t __s; \
unsigned long flags; \
\
arch_efi_call_virt_setup(); \
local_save_flags(flags); \
__s = arch_efi_call_virt(f, args); \
efi_call_virt_check_flags(flags, __stringify(f)); \
arch_efi_call_virt_teardown(); \
\
__s; \
})

Thanks,

Ingo