Re: [PATCH 1/8] riscv: move riscv_noncoherent_supported() out of ZICBOM probe

Jisheng Zhang
2022-10-08T14:09:24Z

On Sat, Oct 08, 2022 at 02:06:00PM +0100, Conor Dooley wrote:
> On Thu, Oct 06, 2022 at 03:08:11PM +0800, Jisheng Zhang wrote:
> > It's a bit wired to call riscv_noncoherent_supported() once when
> > insmod a module. Move the calling out of feature patch func.
> >
> > Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
> > ---
> > arch/riscv/kernel/cpufeature.c | 7 +------
> > arch/riscv/kernel/setup.c | 4 ++++
> > 2 files changed, 5 insertions(+), 6 deletions(-)
> >
> > diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> > index 3b5583db9d80..03611b3ef45e 100644
> > --- a/arch/riscv/kernel/cpufeature.c
> > +++ b/arch/riscv/kernel/cpufeature.c
> > @@ -272,12 +272,7 @@ static bool __init_or_module cpufeature_probe_zicbom(unsigned int stage)
> > case RISCV_ALTERNATIVES_EARLY_BOOT:
> > return false;
> > default:
> > - if (riscv_isa_extension_available(NULL, ZICBOM)) {
> > - riscv_noncoherent_supported();
> > - return true;
> > - } else {
> > - return false;
> > - }
> > + return riscv_isa_extension_available(NULL, ZICBOM);
> > }
> > #endif
> >
> > diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
> > index 2dfc463b86bb..1a055c3f5d9d 100644
> > --- a/arch/riscv/kernel/setup.c
> > +++ b/arch/riscv/kernel/setup.c
> > @@ -299,6 +299,10 @@ void __init setup_arch(char **cmdline_p)
> > riscv_init_cbom_blocksize();
> > riscv_fill_hwcap();
> > apply_boot_alternatives();
> > +#ifdef CONFIG_RISCV_DMA_NONCOHERENT
> > + if (riscv_isa_extension_available(NULL, ZICBOM))
> > + riscv_noncoherent_supported();
> > +#endif
>
> I have a personal bias against ifdefs where possible, maybe @Heiko
> remembers why riscv_noncoherent_supported() was not defined as something
> like `void riscv_noncoherent_support(void){}` for when that CONFIG is
> not enabled? If it was this could become a an IS_ENABLED & we wouldn't
> have to be so careful about wrapping it's usage in ifdefs.

Good idea. Will do in newer version.

>
> Your change in isolation makes sense to me though, so:
> Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
>
> Thanks,
> Conor.
>
> > }
> >
> > static int __init topology_init(void)
> > --
> > 2.37.2
> >