[PATCH V5 2/3] powerpc/mm: Use generic version of pmdp_clear_flush

[Andrew Morton]

On Fri, 15 May 2015 21:12:29 +0530 "Aneesh Kumar K.V" <aneesh.kumar at linux.vnet.ibm.com> wrote:

> Also move the pmd_trans_huge check to generic code.
> 
> ...
>
> --- a/include/asm-generic/pgtable.h
> +++ b/include/asm-generic/pgtable.h
> @@ -196,7 +196,12 @@ static inline pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
>  					unsigned long address,
>  					pmd_t *pmdp)
>  {
> -	return pmdp_clear_flush(vma, address, pmdp);
> +	pmd_t pmd;
> +	VM_BUG_ON(address & ~HPAGE_PMD_MASK);
> +	VM_BUG_ON(pmd_trans_huge(*pmdp));
> +	pmd = pmdp_get_and_clear(vma->vm_mm, address, pmdp);
> +	flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);
> +	return pmd;
>  }

x86_64 allmodconfig:

In file included from ./arch/x86/include/asm/pgtable.h:878,
                 from include/linux/mm.h:53,
                 from include/linux/suspend.h:8,
                 from arch/x86/kernel/asm-offsets.c:12:
include/asm-generic/pgtable.h: In function 'pmdp_collapse_flush':
include/asm-generic/pgtable.h:199: error: 'HPAGE_PMD_MASK' undeclared (first use in this function)
include/asm-generic/pgtable.h:199: error: (Each undeclared identifier is reported only once
include/asm-generic/pgtable.h:199: error: for each function it appears in.)
include/asm-generic/pgtable.h:202: error: implicit declaration of function 'flush_tlb_range'
include/asm-generic/pgtable.h:202: error: 'HPAGE_PMD_SIZE' undeclared (first use in this function)


Including linux/huge_mm.h doesn't work.  A suitable fix would be to
move this into a .c file.