[PATCH v2] arm64: Fix double TCR_T0SZ_OFFSET shift
Seongsu Park
sgsu.park at samsung.com
Sun Apr 7 19:19:25 PDT 2024
> On Wed, Apr 03, 2024 at 11:42:36AM +0900, Seongsu Park wrote:
> > We have already shifted the value of t0sz in TCR_T0SZ by
TCR_T0SZ_OFFSET.
> > So, the TCR_T0SZ_OFFSET shift here should be removed.
>
> Can we please write a better commit message?
>
> This doesn't explain:
>
> * Where we have already shifted the value of t0sz, nor why it makes sense
> to do
> that there.
>
> * That the value of TCR_T0SZ_OFFSET is 0, and hence shifting this
> repeatedly is
> beningn, and this patch is a cleanup rather than a fix.
>
> Mark.
Thank you for feedback. I'll send v3 patch.
In v3, We will upgrade the commit message, and add the cpu_set_tcr_t0sz
macro.
Please check v3!
>
> > Co-developed-by: Leem ChaeHoon <infinite.run at gmail.com>
> > Signed-off-by: Leem ChaeHoon <infinite.run at gmail.com>
> > Co-developed-by: Gyeonggeon Choi <gychoi at student.42seoul.kr>
> > Signed-off-by: Gyeonggeon Choi <gychoi at student.42seoul.kr>
> > Co-developed-by: Soomin Cho <to.soomin at gmail.com>
> > Signed-off-by: Soomin Cho <to.soomin at gmail.com>
> > Co-developed-by: DaeRo Lee <skseofh at gmail.com>
> > Signed-off-by: DaeRo Lee <skseofh at gmail.com>
> > Co-developed-by: kmasta <kmasta.study at gmail.com>
> > Signed-off-by: kmasta <kmasta.study at gmail.com>
> > Signed-off-by: Seongsu Park <sgsu.park at samsung.com>
> > ---
> >
> > Changes in v2:
> > - Condition is updated
> >
> > ---
> > arch/arm64/include/asm/mmu_context.h | 4 ++--
> > 1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/arch/arm64/include/asm/mmu_context.h
> > b/arch/arm64/include/asm/mmu_context.h
> > index c768d16b81a4..bd19f4c758b7 100644
> > --- a/arch/arm64/include/asm/mmu_context.h
> > +++ b/arch/arm64/include/asm/mmu_context.h
> > @@ -72,11 +72,11 @@ static inline void __cpu_set_tcr_t0sz(unsigned
> > long t0sz) {
> > unsigned long tcr = read_sysreg(tcr_el1);
> >
> > - if ((tcr & TCR_T0SZ_MASK) >> TCR_T0SZ_OFFSET == t0sz)
> > + if ((tcr & TCR_T0SZ_MASK) == t0sz)
> > return;
> >
> > tcr &= ~TCR_T0SZ_MASK;
> > - tcr |= t0sz << TCR_T0SZ_OFFSET;
> > + tcr |= t0sz;
> > write_sysreg(tcr, tcr_el1);
> > isb();
> > }
> > --
> > 2.34.1
> >
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