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

Conor Dooley
2022-10-13T05:37:59Z

On 8 October 2022 14:59:37 IST, Jisheng Zhang <jszhang@kernel.org> wrote:
>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.

Given this comment and the LKP report I've marked the series as changes requested in patchwork FYI.

Thanks,
Conor.

>
>>
>> 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
>> >