[PATCHv2] remove unnecessary cache flush on v6 copypage

[PATCHv2] remove unnecessary cache flush on v6 copypage

[Heechul Yun]

ARM: mm: remove unnecessary cache flush on v6 copypage

Originally introduced to maintain coherency between icache and dcache
in v6 nonaliasing mode. This is now handled by __sync_icache_dcache since
c0177800, therefore unneceary in this function.  

Signed-off-by: Heechul Yun <heechul@illinois.edu>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
--
arch/arm/mm/copypage-v6.c |    1 -
 1 files changed, 0 insertions(+), 1 deletions(-)

diff --git a/arch/arm/mm/copypage-v6.c b/arch/arm/mm/copypage-v6.c
index bdba6c6..63cca00 100644
--- a/arch/arm/mm/copypage-v6.c
+++ b/arch/arm/mm/copypage-v6.c
@@ -41,7 +41,6 @@ static void v6_copy_user_highpage_nonaliasing(struct page *to,
 	kfrom = kmap_atomic(from, KM_USER0);
 	kto = kmap_atomic(to, KM_USER1);
 	copy_page(kto, kfrom);
-	__cpuc_flush_dcache_area(kto, PAGE_SIZE);
 	kunmap_atomic(kto, KM_USER1);
 	kunmap_atomic(kfrom, KM_USER0);
 }

[PATCHv2] remove unnecessary cache flush on v6 copypage

[Catalin Marinas]

On Thu, Jul 07, 2011 at 09:30:19AM -0500, Heechul Yun wrote:
> ARM: mm: remove unnecessary cache flush on v6 copypage

Just move this line in the subject and remove it from the body.

> Originally introduced to maintain coherency between icache and dcache
> in v6 nonaliasing mode. This is now handled by __sync_icache_dcache since
> c0177800, therefore unneceary in this function.  

Minor typo - "unnecessary".

Thanks.

-- 
Catalin

[PATCHv2] remove unnecessary cache flush on v6 copypage

[Russell King - ARM Linux]

On Thu, Jul 07, 2011 at 09:30:19AM -0500, Heechul Yun wrote:
> 
> ARM: mm: remove unnecessary cache flush on v6 copypage
> 
> Originally introduced to maintain coherency between icache and dcache
> in v6 nonaliasing mode. This is now handled by __sync_icache_dcache since
> c0177800, therefore unneceary in this function.  
> 
> Signed-off-by: Heechul Yun <heechul@illinois.edu>
> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
> --
> arch/arm/mm/copypage-v6.c |    1 -
>  1 files changed, 0 insertions(+), 1 deletions(-)
> 
> diff --git a/arch/arm/mm/copypage-v6.c b/arch/arm/mm/copypage-v6.c
> index bdba6c6..63cca00 100644
> --- a/arch/arm/mm/copypage-v6.c
> +++ b/arch/arm/mm/copypage-v6.c
> @@ -41,7 +41,6 @@ static void v6_copy_user_highpage_nonaliasing(struct page *to,
>  	kfrom = kmap_atomic(from, KM_USER0);
>  	kto = kmap_atomic(to, KM_USER1);
>  	copy_page(kto, kfrom);
> -	__cpuc_flush_dcache_area(kto, PAGE_SIZE);
>  	kunmap_atomic(kto, KM_USER1);
>  	kunmap_atomic(kfrom, KM_USER0);
>  }

The above patch is fine (it has tabs preserved) but the version in the
patch system has spaces instead (each space character has been replaced
with a '.') and so doesn't apply:

$ pdb getpatch 6995/1 |tr ' ' '.'
Patch:.6995/1:.mm:.remove.unnecessary.cache.flush.on.v6.copypage
From:.Heechul.Yun
-------------------------------------------------------------------------------
.arch/arm/mm/copypage-v6.c.|....1.-
.1.file.changed,.1.deletion(-)
-------------------------------------------------------------------------------
diff.--git.a/arch/arm/mm/copypage-v6.c.b/arch/arm/mm/copypage-v6.c
index.bdba6c6..63cca00.100644
---.a/arch/arm/mm/copypage-v6.c
+++.b/arch/arm/mm/copypage-v6.c
@@.-41,7.+41,6.@@.static.void.v6_copy_user_highpage_nonaliasing(struct.page.*to,........kfrom.=.kmap_atomic(from,.KM_USER0);
........kto.=.kmap_atomic(to,.KM_USER1);
........copy_page(kto,.kfrom);
-.......__cpuc_flush_dcache_area(kto,.PAGE_SIZE);
........kunmap_atomic(kto,.KM_USER1);
........kunmap_atomic(kfrom,.KM_USER0);
.}

[PATCHv2] remove unnecessary cache flush on v6 copypage

[Catalin Marinas]

On Fri, Jul 08, 2011 at 10:35:42AM +0100, Russell King - ARM Linux wrote:
> On Thu, Jul 07, 2011 at 09:30:19AM -0500, Heechul Yun wrote:
> > ARM: mm: remove unnecessary cache flush on v6 copypage
> > 
> > Originally introduced to maintain coherency between icache and dcache
> > in v6 nonaliasing mode. This is now handled by __sync_icache_dcache since
> > c0177800, therefore unneceary in this function.  
> > 
> > Signed-off-by: Heechul Yun <heechul@illinois.edu>
> > Acked-by: Catalin Marinas <catalin.marinas@arm.com>
> > --
> > arch/arm/mm/copypage-v6.c |    1 -
> >  1 files changed, 0 insertions(+), 1 deletions(-)
> > 
> > diff --git a/arch/arm/mm/copypage-v6.c b/arch/arm/mm/copypage-v6.c
> > index bdba6c6..63cca00 100644
> > --- a/arch/arm/mm/copypage-v6.c
> > +++ b/arch/arm/mm/copypage-v6.c
> > @@ -41,7 +41,6 @@ static void v6_copy_user_highpage_nonaliasing(struct page *to,
> >  	kfrom = kmap_atomic(from, KM_USER0);
> >  	kto = kmap_atomic(to, KM_USER1);
> >  	copy_page(kto, kfrom);
> > -	__cpuc_flush_dcache_area(kto, PAGE_SIZE);
> >  	kunmap_atomic(kto, KM_USER1);
> >  	kunmap_atomic(kfrom, KM_USER0);
> >  }
> 
> The above patch is fine (it has tabs preserved) but the version in the
> patch system has spaces instead (each space character has been replaced
> with a '.') and so doesn't apply:

Does your patch system now understand a From: line in the patch log (and
preserve the author)? I can upload the patch on Heechul's behalf.

-- 
Catalin

[PATCHv2] remove unnecessary cache flush on v6 copypage

[heechul Yun]

I just resubmitted the patch to the patch system (6995/2).

Thank you for your patience.

On Fri, Jul 8, 2011 at 2:35 AM, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:
> On Thu, Jul 07, 2011 at 09:30:19AM -0500, Heechul Yun wrote:
>>
>> ARM: mm: remove unnecessary cache flush on v6 copypage
>>
>> Originally introduced to maintain coherency between icache and dcache
>> in v6 nonaliasing mode. This is now handled by __sync_icache_dcache since
>> c0177800, therefore unneceary in this function.
>>
>> Signed-off-by: Heechul Yun <heechul@illinois.edu>
>> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
>> --
>> arch/arm/mm/copypage-v6.c | ? ?1 -
>> ?1 files changed, 0 insertions(+), 1 deletions(-)
>>
>> diff --git a/arch/arm/mm/copypage-v6.c b/arch/arm/mm/copypage-v6.c
>> index bdba6c6..63cca00 100644
>> --- a/arch/arm/mm/copypage-v6.c
>> +++ b/arch/arm/mm/copypage-v6.c
>> @@ -41,7 +41,6 @@ static void v6_copy_user_highpage_nonaliasing(struct page *to,
>> ? ? ? kfrom = kmap_atomic(from, KM_USER0);
>> ? ? ? kto = kmap_atomic(to, KM_USER1);
>> ? ? ? copy_page(kto, kfrom);
>> - ? ? __cpuc_flush_dcache_area(kto, PAGE_SIZE);
>> ? ? ? kunmap_atomic(kto, KM_USER1);
>> ? ? ? kunmap_atomic(kfrom, KM_USER0);
>> ?}
>
> The above patch is fine (it has tabs preserved) but the version in the
> patch system has spaces instead (each space character has been replaced
> with a '.') and so doesn't apply:
>
> $ pdb getpatch 6995/1 |tr ' ' '.'
> Patch:.6995/1:.mm:.remove.unnecessary.cache.flush.on.v6.copypage
> From:.Heechul.Yun
> -------------------------------------------------------------------------------
> .arch/arm/mm/copypage-v6.c.|....1.-
> .1.file.changed,.1.deletion(-)
> -------------------------------------------------------------------------------
> diff.--git.a/arch/arm/mm/copypage-v6.c.b/arch/arm/mm/copypage-v6.c
> index.bdba6c6..63cca00.100644
> ---.a/arch/arm/mm/copypage-v6.c
> +++.b/arch/arm/mm/copypage-v6.c
> @@.-41,7.+41,6.@@.static.void.v6_copy_user_highpage_nonaliasing(struct.page.*to,........kfrom.=.kmap_atomic(from,.KM_USER0);
> ........kto.=.kmap_atomic(to,.KM_USER1);
> ........copy_page(kto,.kfrom);
> -.......__cpuc_flush_dcache_area(kto,.PAGE_SIZE);
> ........kunmap_atomic(kto,.KM_USER1);
> ........kunmap_atomic(kfrom,.KM_USER0);
> .}
>
>