Re: [PATCH v3 1/5] powerpc/interrupt: Rename and lightly change syscall_exit_prepare_main()

[Christophe Leroy]

Le 17/06/2021 à 13:25, Nicholas Piggin a écrit :
> Excerpts from Christophe Leroy's message of June 15, 2021 6:33 pm:
> > Rename syscall_exit_prepare_main() into interrupt_exit_prepare_main()
> >
> > Make it static as it is not used anywhere else.
> >
> > Pass it the 'ret' so that it can 'or' it directly instead of
> > oring twice, once inside the function and once outside.
> >
> > And remove 'r3' parameter which is not used.
> >
> > Also fix a typo where CONFIG_PPC_BOOK3S should be CONFIG_PPC_BOOK3S_64.
> >
> > Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
> > Reviewed-by: Nicholas Piggin <npiggin@xxxxxxxxx>
> > ---
> > This series applies on top of Nic's series speeding up interrupt return on 64s
> >
> >   arch/powerpc/kernel/interrupt.c | 11 +++++------
> >   1 file changed, 5 insertions(+), 6 deletions(-)
> >
> > diff --git a/arch/powerpc/kernel/interrupt.c b/arch/powerpc/kernel/interrupt.c
> > index 74c995a42399..ba2d602d2da6 100644
> > --- a/arch/powerpc/kernel/interrupt.c
> > +++ b/arch/powerpc/kernel/interrupt.c
> > @@ -243,11 +243,10 @@ static notrace void booke_load_dbcr0(void)
> >   #endif
> >   }
> >   
> > -notrace unsigned long syscall_exit_prepare_main(unsigned long r3,
> > -						struct pt_regs *regs)
> > +static notrace unsigned long
> > +interrupt_exit_user_prepare_main(struct pt_regs *regs, unsigned long ret)
>
> Hmm, I tried switching the order of the arguments thinking it would
> match caller and return registers better but didn't seem to help
> generated code. Yet I think I will make that change to your patch if
> you don't mind.

That's a static function that most likely gets inlined so the order of parameters makes no difference.
I tend to like that almost all functions dealing with interrupts take regs as first param, but I 
have no strong opinion about it so you can change it if that's better for you.

Christophe