[6/7] acpi, apei, ghes: Make unmapping functionality independent from architecture.

Message ID 1397056476-9183-7-git-send-email-tomasz.nowicki@linaro.org
State New
Headers show

Commit Message

Tomasz Nowicki April 9, 2014, 3:14 p.m.
Till now __flush_tlb_one was used for unmapping virtual memory which
is x86 specific function. Replace it with more generic
flush_tlb_kernel_range.

Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
---
 drivers/acpi/apei/ghes.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Borislav Petkov May 13, 2014, 8:11 p.m. | #1
On Wed, Apr 09, 2014 at 05:14:34PM +0200, Tomasz Nowicki wrote:
> Till now __flush_tlb_one was used for unmapping virtual memory which
> is x86 specific function. Replace it with more generic
> flush_tlb_kernel_range.
> 
> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
> ---
>  drivers/acpi/apei/ghes.c |    4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
> index aaf8db3..624878b 100644
> --- a/drivers/acpi/apei/ghes.c
> +++ b/drivers/acpi/apei/ghes.c
> @@ -185,7 +185,7 @@ static void ghes_iounmap_nmi(void __iomem *vaddr_ptr)
>  
>  	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_NMI_PAGE(base));
>  	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
> -	__flush_tlb_one(vaddr);
> +	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
>  }
>  
>  static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
> @@ -195,7 +195,7 @@ static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
>  
>  	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_IRQ_PAGE(base));
>  	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
> -	__flush_tlb_one(vaddr);
> +	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);

flush_tlb_kernel_range() does send an IPI to every core on x86 which is
much more expensive than what __flush_tlb_one does.

Fairer it would be if you added a __flush_tlb_one() version for arm
which does flush_tlb_kernel_range for you.
Tomasz Nowicki May 14, 2014, 12:32 p.m. | #2
On 13.05.2014 22:11, Borislav Petkov wrote:
> On Wed, Apr 09, 2014 at 05:14:34PM +0200, Tomasz Nowicki wrote:
>> Till now __flush_tlb_one was used for unmapping virtual memory which
>> is x86 specific function. Replace it with more generic
>> flush_tlb_kernel_range.
>>
>> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
>> ---
>>   drivers/acpi/apei/ghes.c |    4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
>> index aaf8db3..624878b 100644
>> --- a/drivers/acpi/apei/ghes.c
>> +++ b/drivers/acpi/apei/ghes.c
>> @@ -185,7 +185,7 @@ static void ghes_iounmap_nmi(void __iomem *vaddr_ptr)
>>
>>   	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_NMI_PAGE(base));
>>   	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
>> -	__flush_tlb_one(vaddr);
>> +	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
>>   }
>>
>>   static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
>> @@ -195,7 +195,7 @@ static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
>>
>>   	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_IRQ_PAGE(base));
>>   	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
>> -	__flush_tlb_one(vaddr);
>> +	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
>
> flush_tlb_kernel_range() does send an IPI to every core on x86 which is
> much more expensive than what __flush_tlb_one does.
>
> Fairer it would be if you added a __flush_tlb_one() version for arm
> which does flush_tlb_kernel_range for you.
>

Thanks for comment. I am not sure if maintainers will allow me to add 
sth like __flush_tlb_one() for arm/arm64. Let me ask them directly. 
Catalin, Russell what do you think?

Regards,
Tomasz
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Will Deacon May 14, 2014, 12:35 p.m. | #3
On Wed, May 14, 2014 at 01:32:27PM +0100, Tomasz Nowicki wrote:
> On 13.05.2014 22:11, Borislav Petkov wrote:
> > On Wed, Apr 09, 2014 at 05:14:34PM +0200, Tomasz Nowicki wrote:
> >> Till now __flush_tlb_one was used for unmapping virtual memory which
> >> is x86 specific function. Replace it with more generic
> >> flush_tlb_kernel_range.
> >>
> >> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
> >> ---
> >>   drivers/acpi/apei/ghes.c |    4 ++--
> >>   1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
> >> index aaf8db3..624878b 100644
> >> --- a/drivers/acpi/apei/ghes.c
> >> +++ b/drivers/acpi/apei/ghes.c
> >> @@ -185,7 +185,7 @@ static void ghes_iounmap_nmi(void __iomem *vaddr_ptr)
> >>
> >>   	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_NMI_PAGE(base));
> >>   	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
> >> -	__flush_tlb_one(vaddr);
> >> +	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
> >>   }
> >>
> >>   static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
> >> @@ -195,7 +195,7 @@ static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
> >>
> >>   	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_IRQ_PAGE(base));
> >>   	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
> >> -	__flush_tlb_one(vaddr);
> >> +	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
> >
> > flush_tlb_kernel_range() does send an IPI to every core on x86 which is
> > much more expensive than what __flush_tlb_one does.
> >
> > Fairer it would be if you added a __flush_tlb_one() version for arm
> > which does flush_tlb_kernel_range for you.
> >
> 
> Thanks for comment. I am not sure if maintainers will allow me to add 
> sth like __flush_tlb_one() for arm/arm64. Let me ask them directly. 
> Catalin, Russell what do you think?

I don't have the background for this, but if you don't need broadcasting
(if this avoids IPIs on x86, I guess you don't) then why not use
local_flush_tlb_kernel_range instead?

Will
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Catalin Marinas May 14, 2014, 12:45 p.m. | #4
On Wed, May 14, 2014 at 01:35:42PM +0100, Will Deacon wrote:
> On Wed, May 14, 2014 at 01:32:27PM +0100, Tomasz Nowicki wrote:
> > On 13.05.2014 22:11, Borislav Petkov wrote:
> > > On Wed, Apr 09, 2014 at 05:14:34PM +0200, Tomasz Nowicki wrote:
> > >> Till now __flush_tlb_one was used for unmapping virtual memory which
> > >> is x86 specific function. Replace it with more generic
> > >> flush_tlb_kernel_range.
> > >>
> > >> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
> > >> ---
> > >>   drivers/acpi/apei/ghes.c |    4 ++--
> > >>   1 file changed, 2 insertions(+), 2 deletions(-)
> > >>
> > >> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
> > >> index aaf8db3..624878b 100644
> > >> --- a/drivers/acpi/apei/ghes.c
> > >> +++ b/drivers/acpi/apei/ghes.c
> > >> @@ -185,7 +185,7 @@ static void ghes_iounmap_nmi(void __iomem *vaddr_ptr)
> > >>
> > >>   	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_NMI_PAGE(base));
> > >>   	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
> > >> -	__flush_tlb_one(vaddr);
> > >> +	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
> > >>   }
> > >>
> > >>   static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
> > >> @@ -195,7 +195,7 @@ static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
> > >>
> > >>   	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_IRQ_PAGE(base));
> > >>   	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
> > >> -	__flush_tlb_one(vaddr);
> > >> +	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
> > >
> > > flush_tlb_kernel_range() does send an IPI to every core on x86 which is
> > > much more expensive than what __flush_tlb_one does.
> > >
> > > Fairer it would be if you added a __flush_tlb_one() version for arm
> > > which does flush_tlb_kernel_range for you.
> > >
> > 
> > Thanks for comment. I am not sure if maintainers will allow me to add 
> > sth like __flush_tlb_one() for arm/arm64. Let me ask them directly. 
> > Catalin, Russell what do you think?
> 
> I don't have the background for this, but if you don't need broadcasting
> (if this avoids IPIs on x86, I guess you don't) then why not use
> local_flush_tlb_kernel_range instead?

Is this generic enough (we don't have it on arm64)?
Will Deacon May 14, 2014, 12:48 p.m. | #5
On Wed, May 14, 2014 at 01:45:07PM +0100, Catalin Marinas wrote:
> On Wed, May 14, 2014 at 01:35:42PM +0100, Will Deacon wrote:
> > On Wed, May 14, 2014 at 01:32:27PM +0100, Tomasz Nowicki wrote:
> > > On 13.05.2014 22:11, Borislav Petkov wrote:
> > > > On Wed, Apr 09, 2014 at 05:14:34PM +0200, Tomasz Nowicki wrote:
> > > >> Till now __flush_tlb_one was used for unmapping virtual memory which
> > > >> is x86 specific function. Replace it with more generic
> > > >> flush_tlb_kernel_range.
> > > >>
> > > >> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
> > > >> ---
> > > >>   drivers/acpi/apei/ghes.c |    4 ++--
> > > >>   1 file changed, 2 insertions(+), 2 deletions(-)
> > > >>
> > > >> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
> > > >> index aaf8db3..624878b 100644
> > > >> --- a/drivers/acpi/apei/ghes.c
> > > >> +++ b/drivers/acpi/apei/ghes.c
> > > >> @@ -185,7 +185,7 @@ static void ghes_iounmap_nmi(void __iomem *vaddr_ptr)
> > > >>
> > > >>   	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_NMI_PAGE(base));
> > > >>   	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
> > > >> -	__flush_tlb_one(vaddr);
> > > >> +	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
> > > >>   }
> > > >>
> > > >>   static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
> > > >> @@ -195,7 +195,7 @@ static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
> > > >>
> > > >>   	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_IRQ_PAGE(base));
> > > >>   	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
> > > >> -	__flush_tlb_one(vaddr);
> > > >> +	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
> > > >
> > > > flush_tlb_kernel_range() does send an IPI to every core on x86 which is
> > > > much more expensive than what __flush_tlb_one does.
> > > >
> > > > Fairer it would be if you added a __flush_tlb_one() version for arm
> > > > which does flush_tlb_kernel_range for you.
> > > >
> > > 
> > > Thanks for comment. I am not sure if maintainers will allow me to add 
> > > sth like __flush_tlb_one() for arm/arm64. Let me ask them directly. 
> > > Catalin, Russell what do you think?
> > 
> > I don't have the background for this, but if you don't need broadcasting
> > (if this avoids IPIs on x86, I guess you don't) then why not use
> > local_flush_tlb_kernel_range instead?
> 
> Is this generic enough (we don't have it on arm64)?

Well, it's more popular than __flush_tlb_one and the naming is more
descriptive imo.

Will
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Tomasz Nowicki May 14, 2014, 12:52 p.m. | #6
On 14.05.2014 14:48, Will Deacon wrote:
> On Wed, May 14, 2014 at 01:45:07PM +0100, Catalin Marinas wrote:
>> On Wed, May 14, 2014 at 01:35:42PM +0100, Will Deacon wrote:
>>> On Wed, May 14, 2014 at 01:32:27PM +0100, Tomasz Nowicki wrote:
>>>> On 13.05.2014 22:11, Borislav Petkov wrote:
>>>>> On Wed, Apr 09, 2014 at 05:14:34PM +0200, Tomasz Nowicki wrote:
>>>>>> Till now __flush_tlb_one was used for unmapping virtual memory which
>>>>>> is x86 specific function. Replace it with more generic
>>>>>> flush_tlb_kernel_range.
>>>>>>
>>>>>> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@linaro.org>
>>>>>> ---
>>>>>>    drivers/acpi/apei/ghes.c |    4 ++--
>>>>>>    1 file changed, 2 insertions(+), 2 deletions(-)
>>>>>>
>>>>>> diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
>>>>>> index aaf8db3..624878b 100644
>>>>>> --- a/drivers/acpi/apei/ghes.c
>>>>>> +++ b/drivers/acpi/apei/ghes.c
>>>>>> @@ -185,7 +185,7 @@ static void ghes_iounmap_nmi(void __iomem *vaddr_ptr)
>>>>>>
>>>>>>    	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_NMI_PAGE(base));
>>>>>>    	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
>>>>>> -	__flush_tlb_one(vaddr);
>>>>>> +	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
>>>>>>    }
>>>>>>
>>>>>>    static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
>>>>>> @@ -195,7 +195,7 @@ static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
>>>>>>
>>>>>>    	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_IRQ_PAGE(base));
>>>>>>    	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
>>>>>> -	__flush_tlb_one(vaddr);
>>>>>> +	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
>>>>>
>>>>> flush_tlb_kernel_range() does send an IPI to every core on x86 which is
>>>>> much more expensive than what __flush_tlb_one does.
>>>>>
>>>>> Fairer it would be if you added a __flush_tlb_one() version for arm
>>>>> which does flush_tlb_kernel_range for you.
>>>>>
>>>>
>>>> Thanks for comment. I am not sure if maintainers will allow me to add
>>>> sth like __flush_tlb_one() for arm/arm64. Let me ask them directly.
>>>> Catalin, Russell what do you think?
>>>
>>> I don't have the background for this, but if you don't need broadcasting
>>> (if this avoids IPIs on x86, I guess you don't) then why not use
>>> local_flush_tlb_kernel_range instead?
>>
>> Is this generic enough (we don't have it on arm64)?
>
> Well, it's more popular than __flush_tlb_one and the naming is more
> descriptive imo.

I am aiming ARM64 but ideally it should work for x86, arm64 and arm.

Tomasz
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Borislav Petkov May 14, 2014, 1:21 p.m. | #7
On Wed, May 14, 2014 at 02:52:29PM +0200, Tomasz Nowicki wrote:
> I am aiming ARM64 but ideally it should work for x86, arm64 and arm.

I guess you can call it local_flush_tlb_one() which calls
__flush_tlb_one() on x86 and flush_tlb_kernel_range() on arm*

A bunch of other arches have local_flush_tlb_one so going with that
naming might be on the right track :)

Patch

diff --git a/drivers/acpi/apei/ghes.c b/drivers/acpi/apei/ghes.c
index aaf8db3..624878b 100644
--- a/drivers/acpi/apei/ghes.c
+++ b/drivers/acpi/apei/ghes.c
@@ -185,7 +185,7 @@  static void ghes_iounmap_nmi(void __iomem *vaddr_ptr)
 
 	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_NMI_PAGE(base));
 	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
-	__flush_tlb_one(vaddr);
+	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
 }
 
 static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
@@ -195,7 +195,7 @@  static void ghes_iounmap_irq(void __iomem *vaddr_ptr)
 
 	BUG_ON(vaddr != (unsigned long)GHES_IOREMAP_IRQ_PAGE(base));
 	unmap_kernel_range_noflush(vaddr, PAGE_SIZE);
-	__flush_tlb_one(vaddr);
+	flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE);
 }
 
 static int ghes_estatus_pool_init(void)