Re: [cocci] [PATCH v3 2/6] coccinelle: misc: Add field_modify script

[Luo Jie]

On 4/24/2025 12:35 AM, Markus Elfring wrote:
> …
> > > -reg &= ~mask;
> > > -reg |= FIELD_PREP
> > > +       FIELD_MODIFY
> > >                     (mask,
> > > +                  &reg,
> > >                      val
> > >                     );
> …
> > With this code variant, there is no space prior to &reg, here is the
> > example code changes generated by the SmPL code as below, is this expected?
> …
> > +++ b/drivers/phy/starfive/phy-jh7110-dphy-tx.c
> > @@ -244,8 +244,7 @@ static int stf_dphy_configure(struct phy
> >          i = stf_dphy_get_config_index(bitrate);
> >
> >          tmp = readl(dphy->topsys + STF_DPHY_APBIFSAIF_SYSCFG(100));
> > -       tmp &= ~STF_DPHY_REFCLK_IN_SEL;
> > -       tmp |= FIELD_PREP(STF_DPHY_REFCLK_IN_SEL, STF_DPHY_REFCLK_12M);
> > +       FIELD_MODIFY(STF_DPHY_REFCLK_IN_SEL,&tmp, STF_DPHY_REFCLK_12M);
> >          writel(tmp, dphy->topsys + STF_DPHY_APBIFSAIF_SYSCFG(100));
>
> The Coccinelle software is still evolving somehow.
> Thus your test result can trigger further development considerations.
> I hope that clarifications and corresponding improvements can be achieved
> also according to such source code layout concerns.
>
> Regards,
> Markus

OK, understand. I will keep the original patch as below for now, as we
need to ensure the script generates code with the expected style.
+- reg &= ~mask;
+- reg |= FIELD_PREP(mask, val);
++ FIELD_MODIFY(mask, &reg, val);

In addition, below case is filed to request this improvement on the
coccinelle project.
https://github.com/coccinelle/coccinelle/issues/397

Thanks.