Re: [PATCH v6 07/24] RISC-V: Use the minor version mask while computing sbi version

[Atish Patra]

On 4/15/24 06:06, Andrew Jones wrote:
> On Wed, Apr 10, 2024 at 05:07:35PM -0700, Atish Patra wrote:
> > As per the SBI specification, minor version is encoded in the
> > lower 24 bits only. Make sure that the SBI version is computed
> > with the appropriate mask.
> >
> > Currently, there is no minor version in use. Thus, it doesn't
> > change anything functionality but it is good to be compliant with
> > the specification.
> >
> > Signed-off-by: Atish Patra <atishp@xxxxxxxxxxxx>
> > ---
> >   arch/riscv/include/asm/sbi.h | 4 ++--
> >   1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
> > index f31650b10899..935b082d6a6c 100644
> > --- a/arch/riscv/include/asm/sbi.h
> > +++ b/arch/riscv/include/asm/sbi.h
> > @@ -367,8 +367,8 @@ static inline unsigned long sbi_minor_version(void)
> >   static inline unsigned long sbi_mk_version(unsigned long major,
> >   					    unsigned long minor)
> >   {
> > -	return ((major & SBI_SPEC_VERSION_MAJOR_MASK) <<
> > -		SBI_SPEC_VERSION_MAJOR_SHIFT) | minor;
> > +	return ((major & SBI_SPEC_VERSION_MAJOR_MASK) << SBI_SPEC_VERSION_MAJOR_SHIFT
> > +		| (minor & SBI_SPEC_VERSION_MINOR_MASK));
>
> The previous version had ((major & major_mask) << major_shift) | minor
> (parentheses around all the major bits before the OR). Now we have
> parentheses around everything, which aren't necessary, and no longer

We have to use parentheses around | to avoid compiler warnings 
(-Wparentheses)

Are you only concerned about the outer parentheses ? I have removed it.

> have them around all the major bits before the OR. We don't need the
> parentheses around the major bits, since shift has higher precedence
> than OR, but I'd probably keep them.

Is this what you prefer?

return ((major & SBI_SPEC_VERSION_MAJOR_MASK) << 
SBI_SPEC_VERSION_MAJOR_SHIFT) | (minor & SBI_SPEC_VERSION_MINOR_MASK); 




> Otherwise,
>
> Reviewed-by: Andrew Jones <ajones@xxxxxxxxxxxxxxxx>
>
> >   }
> >   
> >   int sbi_err_map_linux_errno(int err);
> > --
> > 2.34.1
>
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