diff mbox series

s390/mm: Use pmd_pgtable_page() helper in __gmap_segment_gaddr()

Message ID 20221125034502.1559986-1-anshuman.khandual@arm.com (mailing list archive)
State New
Headers show
Series s390/mm: Use pmd_pgtable_page() helper in __gmap_segment_gaddr() | expand

Commit Message

Anshuman Khandual Nov. 25, 2022, 3:45 a.m. UTC
In __gmap_segment_gaddr() pmd level page table page is being extracted from
the pmd pointer, similar to pmd_pgtable_page() implementation. This reduces
some redundancy by directly using pmd_pgtable_page() instead,  though first
making it available.

Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: kvm@vger.kernel.org
Cc: linux-s390@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
---
This applies on v6.1-rc6 but after the following patch. Build tested for
s390 plaform (defconfig).

https://lore.kernel.org/all/20221124131641.1523772-1-anshuman.khandual@arm.com/

 arch/s390/mm/gmap.c | 5 ++---
 include/linux/mm.h  | 2 +-
 2 files changed, 3 insertions(+), 4 deletions(-)

Comments

Alexander Gordeev Nov. 28, 2022, 6:07 a.m. UTC | #1
On Fri, Nov 25, 2022 at 09:15:02AM +0530, Anshuman Khandual wrote:

Hi Anshuman,

> In __gmap_segment_gaddr() pmd level page table page is being extracted from
> the pmd pointer, similar to pmd_pgtable_page() implementation. This reduces
> some redundancy by directly using pmd_pgtable_page() instead,  though first
> making it available.

[...]

> diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
> index 02d15c8dc92e..8947451ae021 100644
> --- a/arch/s390/mm/gmap.c
> +++ b/arch/s390/mm/gmap.c
> @@ -336,12 +336,11 @@ static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
>  static unsigned long __gmap_segment_gaddr(unsigned long *entry)
>  {
>  	struct page *page;
> -	unsigned long offset, mask;
> +	unsigned long offset;
>  
>  	offset = (unsigned long) entry / sizeof(unsigned long);
>  	offset = (offset & (PTRS_PER_PMD - 1)) * PMD_SIZE;
> -	mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
> -	page = virt_to_page((void *)((unsigned long) entry & mask));
> +	page = pmd_pgtable_page((pmd_t *) entry);
>  	return page->index + offset;
>  }

Looks okay to me.

> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index e9e387caffac..5ead9e997510 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -2403,7 +2403,7 @@ static inline void pgtable_pte_page_dtor(struct page *page)
>  
>  #if USE_SPLIT_PMD_PTLOCKS
>  
> -static struct page *pmd_pgtable_page(pmd_t *pmd)
> +static inline struct page *pmd_pgtable_page(pmd_t *pmd)
>  {
>  	unsigned long mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
>  	return virt_to_page((void *)((unsigned long) pmd & mask));

This chunk does not appear to belong to this patch.

Thanks!
Anshuman Khandual Nov. 28, 2022, 6:31 a.m. UTC | #2
On 11/28/22 11:37, Alexander Gordeev wrote:
> On Fri, Nov 25, 2022 at 09:15:02AM +0530, Anshuman Khandual wrote:
> 
> Hi Anshuman,
> 
>> In __gmap_segment_gaddr() pmd level page table page is being extracted from
>> the pmd pointer, similar to pmd_pgtable_page() implementation. This reduces
>> some redundancy by directly using pmd_pgtable_page() instead,  though first
>> making it available.
> 
> [...]
> 
>> diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
>> index 02d15c8dc92e..8947451ae021 100644
>> --- a/arch/s390/mm/gmap.c
>> +++ b/arch/s390/mm/gmap.c
>> @@ -336,12 +336,11 @@ static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
>>  static unsigned long __gmap_segment_gaddr(unsigned long *entry)
>>  {
>>  	struct page *page;
>> -	unsigned long offset, mask;
>> +	unsigned long offset;
>>  
>>  	offset = (unsigned long) entry / sizeof(unsigned long);
>>  	offset = (offset & (PTRS_PER_PMD - 1)) * PMD_SIZE;
>> -	mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
>> -	page = virt_to_page((void *)((unsigned long) entry & mask));
>> +	page = pmd_pgtable_page((pmd_t *) entry);
>>  	return page->index + offset;
>>  }
> 
> Looks okay to me.
> 
>> diff --git a/include/linux/mm.h b/include/linux/mm.h
>> index e9e387caffac..5ead9e997510 100644
>> --- a/include/linux/mm.h
>> +++ b/include/linux/mm.h
>> @@ -2403,7 +2403,7 @@ static inline void pgtable_pte_page_dtor(struct page *page)
>>  
>>  #if USE_SPLIT_PMD_PTLOCKS
>>  
>> -static struct page *pmd_pgtable_page(pmd_t *pmd)
>> +static inline struct page *pmd_pgtable_page(pmd_t *pmd)
>>  {
>>  	unsigned long mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
>>  	return virt_to_page((void *)((unsigned long) pmd & mask));
> 
> This chunk does not appear to belong to this patch.

Should not this helper be made a 'static inline' before using it else where ?
Alexander Gordeev Nov. 28, 2022, 7:13 a.m. UTC | #3
On Mon, Nov 28, 2022 at 12:01:06PM +0530, Anshuman Khandual wrote:
> >> diff --git a/include/linux/mm.h b/include/linux/mm.h
> >> index e9e387caffac..5ead9e997510 100644
> >> --- a/include/linux/mm.h
> >> +++ b/include/linux/mm.h
> >> @@ -2403,7 +2403,7 @@ static inline void pgtable_pte_page_dtor(struct page *page)
> >>  
> >>  #if USE_SPLIT_PMD_PTLOCKS
> >>  
> >> -static struct page *pmd_pgtable_page(pmd_t *pmd)
> >> +static inline struct page *pmd_pgtable_page(pmd_t *pmd)
> >>  {
> >>  	unsigned long mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
> >>  	return virt_to_page((void *)((unsigned long) pmd & mask));
> > 
> > This chunk does not appear to belong to this patch.
> 
> Should not this helper be made a 'static inline' before using it else where ?

Probably yes, but it is not kvm s390-specific change.

I guess, you wanted to make it together or as a follow-up to this one?
https://lore.kernel.org/all/20221124131641.1523772-1-anshuman.khandual@arm.com/
Anshuman Khandual Nov. 28, 2022, 7:43 a.m. UTC | #4
On 11/28/22 12:43, Alexander Gordeev wrote:
> On Mon, Nov 28, 2022 at 12:01:06PM +0530, Anshuman Khandual wrote:
>>>> diff --git a/include/linux/mm.h b/include/linux/mm.h
>>>> index e9e387caffac..5ead9e997510 100644
>>>> --- a/include/linux/mm.h
>>>> +++ b/include/linux/mm.h
>>>> @@ -2403,7 +2403,7 @@ static inline void pgtable_pte_page_dtor(struct page *page)
>>>>  
>>>>  #if USE_SPLIT_PMD_PTLOCKS
>>>>  
>>>> -static struct page *pmd_pgtable_page(pmd_t *pmd)
>>>> +static inline struct page *pmd_pgtable_page(pmd_t *pmd)
>>>>  {
>>>>  	unsigned long mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
>>>>  	return virt_to_page((void *)((unsigned long) pmd & mask));
>>>
>>> This chunk does not appear to belong to this patch.
>>
>> Should not this helper be made a 'static inline' before using it else where ?
> 
> Probably yes, but it is not kvm s390-specific change.

Right, just that the s390 change here is the first instance where this helper
is being used outside the header, hence kept them together.

> 
> I guess, you wanted to make it together or as a follow-up to this one?
> https://lore.kernel.org/all/20221124131641.1523772-1-anshuman.khandual@arm.com/
> 
Unless too much trouble, could we just keep it here as proposed.
Alexander Gordeev Nov. 28, 2022, 8:18 a.m. UTC | #5
On Mon, Nov 28, 2022 at 01:13:45PM +0530, Anshuman Khandual wrote:
> >>>> index e9e387caffac..5ead9e997510 100644
> >>>> --- a/include/linux/mm.h
> >>>> +++ b/include/linux/mm.h
> >>>> @@ -2403,7 +2403,7 @@ static inline void pgtable_pte_page_dtor(struct page *page)
> >>>>  
> >>>>  #if USE_SPLIT_PMD_PTLOCKS
> >>>>  
> >>>> -static struct page *pmd_pgtable_page(pmd_t *pmd)
> >>>> +static inline struct page *pmd_pgtable_page(pmd_t *pmd)
> >>>>  {
> >>>>  	unsigned long mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
> >>>>  	return virt_to_page((void *)((unsigned long) pmd & mask));
> >>>
> >>> This chunk does not appear to belong to this patch.
> >>
> >> Should not this helper be made a 'static inline' before using it else where ?
> > 
> > Probably yes, but it is not kvm s390-specific change.
> 
> Right, just that the s390 change here is the first instance where this helper
> is being used outside the header, hence kept them together.
> 
> > 
> > I guess, you wanted to make it together or as a follow-up to this one?
> > https://lore.kernel.org/all/20221124131641.1523772-1-anshuman.khandual@arm.com/
> > 
> Unless too much trouble, could we just keep it here as proposed.

For s390 part:

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>

Thanks!
diff mbox series

Patch

diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index 02d15c8dc92e..8947451ae021 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -336,12 +336,11 @@  static int gmap_alloc_table(struct gmap *gmap, unsigned long *table,
 static unsigned long __gmap_segment_gaddr(unsigned long *entry)
 {
 	struct page *page;
-	unsigned long offset, mask;
+	unsigned long offset;
 
 	offset = (unsigned long) entry / sizeof(unsigned long);
 	offset = (offset & (PTRS_PER_PMD - 1)) * PMD_SIZE;
-	mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
-	page = virt_to_page((void *)((unsigned long) entry & mask));
+	page = pmd_pgtable_page((pmd_t *) entry);
 	return page->index + offset;
 }
 
diff --git a/include/linux/mm.h b/include/linux/mm.h
index e9e387caffac..5ead9e997510 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2403,7 +2403,7 @@  static inline void pgtable_pte_page_dtor(struct page *page)
 
 #if USE_SPLIT_PMD_PTLOCKS
 
-static struct page *pmd_pgtable_page(pmd_t *pmd)
+static inline struct page *pmd_pgtable_page(pmd_t *pmd)
 {
 	unsigned long mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
 	return virt_to_page((void *)((unsigned long) pmd & mask));