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* [PATCH v2] arm64: Fix double TCR_T0SZ_OFFSET shift
       [not found] <CGME20240403024240epcas1p155cd55ca8c1dae6114b970cf3f57084e@epcas1p1.samsung.com>
@ 2024-04-03  2:42 ` Seongsu Park
  2024-04-03 10:01   ` Mark Rutland
  0 siblings, 1 reply; 3+ messages in thread
From: Seongsu Park @ 2024-04-03  2:42 UTC (permalink / raw)
  To: will, catalin.marinas, ardb, mark.rutland
  Cc: linux-arm-kernel, linux-kernel, sgsu.park, Leem ChaeHoon,
	Gyeonggeon Choi, Soomin Cho, DaeRo Lee, kmasta

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.

Co-developed-by: Leem ChaeHoon <infinite.run@gmail.com>
Signed-off-by: Leem ChaeHoon <infinite.run@gmail.com>
Co-developed-by: Gyeonggeon Choi <gychoi@student.42seoul.kr>
Signed-off-by: Gyeonggeon Choi <gychoi@student.42seoul.kr>
Co-developed-by: Soomin Cho <to.soomin@gmail.com>
Signed-off-by: Soomin Cho <to.soomin@gmail.com>
Co-developed-by: DaeRo Lee <skseofh@gmail.com>
Signed-off-by: DaeRo Lee <skseofh@gmail.com>
Co-developed-by: kmasta <kmasta.study@gmail.com>
Signed-off-by: kmasta <kmasta.study@gmail.com>
Signed-off-by: Seongsu Park <sgsu.park@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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^ permalink raw reply related	[flat|nested] 3+ messages in thread

* Re: [PATCH v2] arm64: Fix double TCR_T0SZ_OFFSET shift
  2024-04-03  2:42 ` [PATCH v2] arm64: Fix double TCR_T0SZ_OFFSET shift Seongsu Park
@ 2024-04-03 10:01   ` Mark Rutland
  2024-04-08  2:19     ` Seongsu Park
  0 siblings, 1 reply; 3+ messages in thread
From: Mark Rutland @ 2024-04-03 10:01 UTC (permalink / raw)
  To: Seongsu Park
  Cc: will, catalin.marinas, ardb, linux-arm-kernel, linux-kernel,
	Leem ChaeHoon, Gyeonggeon Choi, Soomin Cho, DaeRo Lee, kmasta

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.

> Co-developed-by: Leem ChaeHoon <infinite.run@gmail.com>
> Signed-off-by: Leem ChaeHoon <infinite.run@gmail.com>
> Co-developed-by: Gyeonggeon Choi <gychoi@student.42seoul.kr>
> Signed-off-by: Gyeonggeon Choi <gychoi@student.42seoul.kr>
> Co-developed-by: Soomin Cho <to.soomin@gmail.com>
> Signed-off-by: Soomin Cho <to.soomin@gmail.com>
> Co-developed-by: DaeRo Lee <skseofh@gmail.com>
> Signed-off-by: DaeRo Lee <skseofh@gmail.com>
> Co-developed-by: kmasta <kmasta.study@gmail.com>
> Signed-off-by: kmasta <kmasta.study@gmail.com>
> Signed-off-by: Seongsu Park <sgsu.park@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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^ permalink raw reply	[flat|nested] 3+ messages in thread

* RE: [PATCH v2] arm64: Fix double TCR_T0SZ_OFFSET shift
  2024-04-03 10:01   ` Mark Rutland
@ 2024-04-08  2:19     ` Seongsu Park
  0 siblings, 0 replies; 3+ messages in thread
From: Seongsu Park @ 2024-04-08  2:19 UTC (permalink / raw)
  To: 'Mark Rutland'
  Cc: will, catalin.marinas, ardb, linux-arm-kernel, linux-kernel,
	'Leem	ChaeHoon', 'Gyeonggeon Choi',
	'Soomin Cho', 'DaeRo Lee', 'kmasta'



> 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@gmail.com>
> > Signed-off-by: Leem ChaeHoon <infinite.run@gmail.com>
> > Co-developed-by: Gyeonggeon Choi <gychoi@student.42seoul.kr>
> > Signed-off-by: Gyeonggeon Choi <gychoi@student.42seoul.kr>
> > Co-developed-by: Soomin Cho <to.soomin@gmail.com>
> > Signed-off-by: Soomin Cho <to.soomin@gmail.com>
> > Co-developed-by: DaeRo Lee <skseofh@gmail.com>
> > Signed-off-by: DaeRo Lee <skseofh@gmail.com>
> > Co-developed-by: kmasta <kmasta.study@gmail.com>
> > Signed-off-by: kmasta <kmasta.study@gmail.com>
> > Signed-off-by: Seongsu Park <sgsu.park@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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^ permalink raw reply	[flat|nested] 3+ messages in thread

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     [not found] <CGME20240403024240epcas1p155cd55ca8c1dae6114b970cf3f57084e@epcas1p1.samsung.com>
2024-04-03  2:42 ` [PATCH v2] arm64: Fix double TCR_T0SZ_OFFSET shift Seongsu Park
2024-04-03 10:01   ` Mark Rutland
2024-04-08  2:19     ` Seongsu Park

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