[PATCH v6 2/7] powerpc/64s: mm: Introduce __pmdp_collapse_flush with mm_struct argument

[Rohan McLure]

> On 14 Feb 2023, at 5:02 pm, Christophe Leroy <christophe.leroy at csgroup.eu> wrote:
> 
> 
> 
> Le 14/02/2023 à 02:59, Rohan McLure a écrit :
>> pmdp_collapse_flush has references in generic code with just three
>> parameters, due to the choice of mm context being implied by the vm_area
>> context parameter.
>> 
>> Define __pmdp_collapse_flush to accept an additional mm_struct *
>> parameter, with pmdp_collapse_flush a macro that unpacks the vma and
>> calls __pmdp_collapse_flush. The mm_struct * parameter is needed in a
>> future patch providing Page Table Check support, which is defined in
>> terms of mm context objects.
>> 
>> Signed-off-by: Rohan McLure <rmclure at linux.ibm.com>
>> ---
>> v6: New patch
>> ---
>>  arch/powerpc/include/asm/book3s/64/pgtable.h | 14 +++++++++++---
>>  1 file changed, 11 insertions(+), 3 deletions(-)
>> 
>> diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
>> index cb4c67bf45d7..9d8b4e25f5ed 100644
>> --- a/arch/powerpc/include/asm/book3s/64/pgtable.h
>> +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
>> @@ -1244,14 +1244,22 @@ static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
>>   return hash__pmdp_huge_get_and_clear(mm, addr, pmdp);
>>  }
>> 
>> -static inline pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
>> - unsigned long address, pmd_t *pmdp)
>> +static inline pmd_t __pmdp_collapse_flush(struct vm_area_struct *vma, struct mm_struct *mm,
>> +  unsigned long address, pmd_t *pmdp)
>>  {
>>   if (radix_enabled())
>>   return radix__pmdp_collapse_flush(vma, address, pmdp);
>>   return hash__pmdp_collapse_flush(vma, address, pmdp);
>>  }
>> -#define pmdp_collapse_flush pmdp_collapse_flush
>> +#define pmdp_collapse_flush(vma, addr, pmdp) \
>> +({ \
>> + struct vm_area_struct *_vma = (vma); \
>> + pmd_t _r; \
>> + \
>> + _r = __pmdp_collapse_flush(_vma, _vma->vm_mm, (addr), (pmdp)); \
>> + \
>> + _r; \
>> +})
> 
> Can you make it a static inline function instead of a ugly macro ?

Due to some header hell, it’s looking like this location only has access to
a prototype for struct vm_area_struct. Might have to remain a macro then.

Probably don’t need to expliclty declare a variable for the macro ‘return’
though.

> 
>> 
>>  #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR_FULL
>>  pmd_t pmdp_huge_get_and_clear_full(struct vm_area_struct *vma,