[PATCH 3/7] arm64: hugetlb: Refactor find_num_contig

[mark.rutland@arm.com (Mark Rutland)]

On Tue, Mar 21, 2017 at 06:04:17PM +0000, Punit Agrawal wrote:
> From: Steve Capper <steve.capper@arm.com>
> 
> As we regularly check for contiguous pte's in the huge accessors, remove
> this extra check from find_num_contig.
> 
> Cc: David Woods <dwoods@mellanox.com>
> Signed-off-by: Steve Capper <steve.capper@arm.com>
> Signed-off-by: Punit Agrawal <punit.agrawal@arm.com>

Reviewed-by: Mark Rutland <mark.rutland@arm.com>

Mark.

> ---
>  arch/arm64/mm/hugetlbpage.c | 17 ++++++++---------
>  1 file changed, 8 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
> index aacbe18e6640..81bc6e4cf714 100644
> --- a/arch/arm64/mm/hugetlbpage.c
> +++ b/arch/arm64/mm/hugetlbpage.c
> @@ -42,15 +42,13 @@ int pud_huge(pud_t pud)
>  }
>  
>  static int find_num_contig(struct mm_struct *mm, unsigned long addr,
> -			   pte_t *ptep, pte_t pte, size_t *pgsize)
> +			   pte_t *ptep, size_t *pgsize)
>  {
>  	pgd_t *pgd = pgd_offset(mm, addr);
>  	pud_t *pud;
>  	pmd_t *pmd;
>  
>  	*pgsize = PAGE_SIZE;
> -	if (!pte_cont(pte))
> -		return 1;
>  	pud = pud_offset(pgd, addr);
>  	pmd = pmd_offset(pud, addr);
>  	if ((pte_t *)pmd == ptep) {
> @@ -65,7 +63,7 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>  {
>  	size_t pgsize;
>  	int i;
> -	int ncontig = find_num_contig(mm, addr, ptep, pte, &pgsize);
> +	int ncontig;
>  	unsigned long pfn;
>  	pgprot_t hugeprot;
>  
> @@ -75,11 +73,12 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
>  	 */
>  	WARN_ON(!pte_present(pte));
>  
> -	if (ncontig == 1) {
> +	if (!pte_cont(pte)) {
>  		set_pte_at(mm, addr, ptep, pte);
>  		return;
>  	}
>  
> +	ncontig = find_num_contig(mm, addr, ptep, &pgsize);
>  	pfn = pte_pfn(pte);
>  	hugeprot = __pgprot(pte_val(pfn_pte(pfn, __pgprot(0))) ^ pte_val(pte));
>  	for (i = 0; i < ncontig; i++) {
> @@ -203,7 +202,7 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
>  		bool is_dirty = false;
>  
>  		cpte = huge_pte_offset(mm, addr);
> -		ncontig = find_num_contig(mm, addr, cpte, *cpte, &pgsize);
> +		ncontig = find_num_contig(mm, addr, cpte, &pgsize);
>  		/* save the 1st pte to return */
>  		pte = ptep_get_and_clear(mm, addr, cpte);
>  		for (i = 1, addr += pgsize; i < ncontig; ++i, addr += pgsize) {
> @@ -243,7 +242,7 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma,
>  		cpte = huge_pte_offset(vma->vm_mm, addr);
>  		pfn = pte_pfn(*cpte);
>  		ncontig = find_num_contig(vma->vm_mm, addr, cpte,
> -					  *cpte, &pgsize);
> +					  &pgsize);
>  		for (i = 0; i < ncontig; ++i, ++cpte, addr += pgsize) {
>  			changed |= ptep_set_access_flags(vma, addr, cpte,
>  							pfn_pte(pfn,
> @@ -266,7 +265,7 @@ void huge_ptep_set_wrprotect(struct mm_struct *mm,
>  		size_t pgsize = 0;
>  
>  		cpte = huge_pte_offset(mm, addr);
> -		ncontig = find_num_contig(mm, addr, cpte, *cpte, &pgsize);
> +		ncontig = find_num_contig(mm, addr, cpte, &pgsize);
>  		for (i = 0; i < ncontig; ++i, ++cpte, addr += pgsize)
>  			ptep_set_wrprotect(mm, addr, cpte);
>  	} else {
> @@ -284,7 +283,7 @@ void huge_ptep_clear_flush(struct vm_area_struct *vma,
>  
>  		cpte = huge_pte_offset(vma->vm_mm, addr);
>  		ncontig = find_num_contig(vma->vm_mm, addr, cpte,
> -					  *cpte, &pgsize);
> +					  &pgsize);
>  		for (i = 0; i < ncontig; ++i, ++cpte, addr += pgsize)
>  			ptep_clear_flush(vma, addr, cpte);
>  	} else {
> -- 
> 2.11.0
>