Re: [PATCH v2 02/13] riscv: move riscv_noncoherent_supported() out of ZICBOM probe

Jisheng Zhang
2022-12-05T15:26:42Z

On Sun, Dec 04, 2022 at 10:52:03PM +0100, Heiko Stübner wrote:
> Am Sonntag, 4. Dezember 2022, 18:46:21 CET schrieb Jisheng Zhang:
> > It's a bit weird to call riscv_noncoherent_supported() each time when
> > insmoding a module. Move the calling out of feature patch func.
> >
> > Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
> > Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
> > Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
> > ---
> > arch/riscv/kernel/cpufeature.c | 1 -
> > arch/riscv/kernel/setup.c | 2 ++
> > 2 files changed, 2 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> > index c743f0adc794..364d1fe86bea 100644
> > --- a/arch/riscv/kernel/cpufeature.c
> > +++ b/arch/riscv/kernel/cpufeature.c
> > @@ -274,7 +274,6 @@ static bool __init_or_module cpufeature_probe_zicbom(unsigned int stage)
> > if (!riscv_isa_extension_available(NULL, ZICBOM))
> > return false;
> >
> > - riscv_noncoherent_supported();
> > return true;
> > }
> >
> > diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
> > index 86acd690d529..6eea40bf8c6b 100644
> > --- a/arch/riscv/kernel/setup.c
> > +++ b/arch/riscv/kernel/setup.c
> > @@ -300,6 +300,8 @@ void __init setup_arch(char **cmdline_p)
> > riscv_init_cbom_blocksize();
> > riscv_fill_hwcap();
> > apply_boot_alternatives();
> > + if (riscv_isa_extension_available(NULL, ZICBOM))
> > + riscv_noncoherent_supported();
>
> hmm, this changes the behaviour slightly. In the probe function there
> is the
> if (!IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM))
> return false;
> at the top, so with this change the second WARN_TAINT in arch_setup_dma_ops
> will behave differently

thanks for the information. below code can keep the behavior:

if (IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM) &&
riscv_isa_extension_available(NULL, ZICBOM))
riscv_noncoherent_supported();

will wait for one more day for more review comments, then will send out
a v3
>
> Heiko