[PATCH v4 1/8] arm64: hugetlb: Refactor find_num_contig

From: Punit Agrawal
Date: Wed May 24 2017 - 07:59:26 EST


From: Steve Capper <steve.capper@xxxxxxx>

As we regularly check for contiguous pte's in the huge accessors, remove
this extra check from find_num_contig.

Cc: David Woods <dwoods@xxxxxxxxxxxx>
Signed-off-by: Steve Capper <steve.capper@xxxxxxx>
[ Resolved rebase conflicts due to patch re-ordering ]
Signed-off-by: Punit Agrawal <punit.agrawal@xxxxxxx>
---
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 69b8200b1cfd..710bf935a473 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) {
@@ -65,15 +63,16 @@ 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;

- 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++) {
@@ -188,7 +187,7 @@ 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) {
@@ -228,7 +227,7 @@ 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,
@@ -251,7 +250,7 @@ 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 {
@@ -269,7 +268,7 @@ 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