@@ -148,22 +148,25 @@ unsigned long hugetlb_mask_last_page(struct hstate *h)
static pte_t get_clear_contig(struct mm_struct *mm,
unsigned long addr,
pte_t *ptep,
- unsigned long pte_num)
+ unsigned long ncontig)
{
- pte_t orig_pte = ptep_get(ptep);
- unsigned long i;
-
- for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++) {
- pte_t pte = ptep_get_and_clear(mm, addr, ptep);
-
- if (pte_dirty(pte))
- orig_pte = pte_mkdirty(orig_pte);
-
- if (pte_young(pte))
- orig_pte = pte_mkyoung(orig_pte);
+ pte_t pte, tmp_pte;
+ bool present;
+
+ pte = ptep_get_and_clear(mm, addr, ptep);
+ present = pte_present(pte);
+ while (--ncontig) {
+ ptep++;
+ addr += PAGE_SIZE;
+ tmp_pte = ptep_get_and_clear(mm, addr, ptep);
+ if (present) {
+ if (pte_dirty(tmp_pte))
+ pte = pte_mkdirty(pte);
+ if (pte_young(tmp_pte))
+ pte = pte_mkyoung(pte);
+ }
}
-
- return orig_pte;
+ return pte;
}
static pte_t get_clear_contig_flush(struct mm_struct *mm,
@@ -212,6 +215,26 @@ static void clear_flush(struct mm_struct *mm,
flush_tlb_range(&vma, saddr, addr);
}
+static int num_contig_ptes_from_size(unsigned long sz, size_t *pgsize)
+{
+ unsigned long hugepage_shift;
+
+ if (sz >= PGDIR_SIZE)
+ hugepage_shift = PGDIR_SHIFT;
+ else if (sz >= P4D_SIZE)
+ hugepage_shift = P4D_SHIFT;
+ else if (sz >= PUD_SIZE)
+ hugepage_shift = PUD_SHIFT;
+ else if (sz >= PMD_SIZE)
+ hugepage_shift = PMD_SHIFT;
+ else
+ hugepage_shift = PAGE_SHIFT;
+
+ *pgsize = 1 << hugepage_shift;
+
+ return sz >> hugepage_shift;
+}
+
/*
* When dealing with NAPOT mappings, the privileged specification indicates that
* "if an update needs to be made, the OS generally should first mark all of the
@@ -226,22 +249,10 @@ void set_huge_pte_at(struct mm_struct *mm,
pte_t pte,
unsigned long sz)
{
- unsigned long hugepage_shift, pgsize;
+ size_t pgsize;
int i, pte_num;
- if (sz >= PGDIR_SIZE)
- hugepage_shift = PGDIR_SHIFT;
- else if (sz >= P4D_SIZE)
- hugepage_shift = P4D_SHIFT;
- else if (sz >= PUD_SIZE)
- hugepage_shift = PUD_SHIFT;
- else if (sz >= PMD_SIZE)
- hugepage_shift = PMD_SHIFT;
- else
- hugepage_shift = PAGE_SHIFT;
-
- pte_num = sz >> hugepage_shift;
- pgsize = 1 << hugepage_shift;
+ pte_num = num_contig_ptes_from_size(sz, &pgsize);
if (!pte_present(pte)) {
for (i = 0; i < pte_num; i++, ptep++, addr += pgsize)
@@ -295,13 +306,14 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
unsigned long addr,
pte_t *ptep, unsigned long sz)
{
+ size_t pgsize;
pte_t orig_pte = ptep_get(ptep);
int pte_num;
if (!pte_napot(orig_pte))
return ptep_get_and_clear(mm, addr, ptep);
- pte_num = napot_pte_num(napot_cont_order(orig_pte));
+ pte_num = num_contig_ptes_from_size(sz, &pgsize);
return get_clear_contig(mm, addr, ptep, pte_num);
}
@@ -351,6 +363,7 @@ void huge_pte_clear(struct mm_struct *mm,
pte_t *ptep,
unsigned long sz)
{
+ size_t pgsize;
pte_t pte = ptep_get(ptep);
int i, pte_num;
@@ -359,8 +372,9 @@ void huge_pte_clear(struct mm_struct *mm,
return;
}
- pte_num = napot_pte_num(napot_cont_order(pte));
- for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++)
+ pte_num = num_contig_ptes_from_size(sz, &pgsize);
+
+ for (i = 0; i < pte_num; i++, addr += pgsize, ptep++)
pte_clear(mm, addr, ptep);
}
Ryan sent a fix [1] for arm64 that applies to riscv too: in some hugetlb functions, we must not use the pte value to get the size of a mapping because the pte may not be present. So use the already present size parameter for huge_pte_clear() and the newly introduced size parameter for huge_ptep_get_and_clear(). And make sure to gather A/D bits only on present ptes. Fixes: 82a1a1f3bfb6 ("riscv: mm: support Svnapot in hugetlb page") Link: https://lore.kernel.org/all/20250217140419.1702389-1-ryan.roberts@arm.com/ [1] Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com> --- arch/riscv/mm/hugetlbpage.c | 76 ++++++++++++++++++++++--------------- 1 file changed, 45 insertions(+), 31 deletions(-)