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-rw-r--r--arch/arm64/mm/hugetlbpage.c112
1 files changed, 91 insertions, 21 deletions
diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index 08deed7c71f0..b82df85fe920 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -68,6 +68,66 @@ static int find_num_contig(struct mm_struct *mm, unsigned long addr,
return CONT_PTES;
}
+/*
+ * Changing some bits of contiguous entries requires us to follow a
+ * Break-Before-Make approach, breaking the whole contiguous set
+ * before we can change any entries. See ARM DDI 0487A.k_iss10775,
+ * "Misprogramming of the Contiguous bit", page D4-1762.
+ *
+ * This helper performs the break step.
+ */
+static pte_t get_clear_flush(struct mm_struct *mm,
+ unsigned long addr,
+ pte_t *ptep,
+ unsigned long pgsize,
+ unsigned long ncontig)
+{
+ struct vm_area_struct vma = { .vm_mm = mm };
+ pte_t orig_pte = huge_ptep_get(ptep);
+ bool valid = pte_valid(orig_pte);
+ unsigned long i, saddr = addr;
+
+ for (i = 0; i < ncontig; i++, addr += pgsize, ptep++) {
+ pte_t pte = ptep_get_and_clear(mm, addr, ptep);
+
+ /*
+ * If HW_AFDBM is enabled, then the HW could turn on
+ * the dirty bit for any page in the set, so check
+ * them all. All hugetlb entries are already young.
+ */
+ if (pte_dirty(pte))
+ orig_pte = pte_mkdirty(orig_pte);
+ }
+
+ if (valid)
+ flush_tlb_range(&vma, saddr, addr);
+ return orig_pte;
+}
+
+/*
+ * Changing some bits of contiguous entries requires us to follow a
+ * Break-Before-Make approach, breaking the whole contiguous set
+ * before we can change any entries. See ARM DDI 0487A.k_iss10775,
+ * "Misprogramming of the Contiguous bit", page D4-1762.
+ *
+ * This helper performs the break step for use cases where the
+ * original pte is not needed.
+ */
+static void clear_flush(struct mm_struct *mm,
+ unsigned long addr,
+ pte_t *ptep,
+ unsigned long pgsize,
+ unsigned long ncontig)
+{
+ struct vm_area_struct vma = { .vm_mm = mm };
+ unsigned long i, saddr = addr;
+
+ for (i = 0; i < ncontig; i++, addr += pgsize, ptep++)
+ pte_clear(mm, addr, ptep);
+
+ flush_tlb_range(&vma, saddr, addr);
+}
+
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte)
{
@@ -93,6 +153,8 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
dpfn = pgsize >> PAGE_SHIFT;
hugeprot = pte_pgprot(pte);
+ clear_flush(mm, addr, ptep, pgsize, ncontig);
+
for (i = 0; i < ncontig; i++, ptep++, addr += pgsize, pfn += dpfn) {
pr_debug("%s: set pte %p to 0x%llx\n", __func__, ptep,
pte_val(pfn_pte(pfn, hugeprot)));
@@ -194,7 +256,7 @@ pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
- int ncontig, i;
+ int ncontig;
size_t pgsize;
pte_t orig_pte = huge_ptep_get(ptep);
@@ -202,17 +264,8 @@ pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
return ptep_get_and_clear(mm, addr, ptep);
ncontig = find_num_contig(mm, addr, ptep, &pgsize);
- for (i = 0; i < ncontig; i++, addr += pgsize, ptep++) {
- /*
- * If HW_AFDBM is enabled, then the HW could
- * turn on the dirty bit for any of the page
- * in the set, so check them all.
- */
- if (pte_dirty(ptep_get_and_clear(mm, addr, ptep)))
- orig_pte = pte_mkdirty(orig_pte);
- }
- return orig_pte;
+ return get_clear_flush(mm, addr, ptep, pgsize, ncontig);
}
int huge_ptep_set_access_flags(struct vm_area_struct *vma,
@@ -223,18 +276,25 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma,
size_t pgsize = 0;
unsigned long pfn = pte_pfn(pte), dpfn;
pgprot_t hugeprot;
+ pte_t orig_pte;
if (!pte_cont(pte))
return ptep_set_access_flags(vma, addr, ptep, pte, dirty);
ncontig = find_num_contig(vma->vm_mm, addr, ptep, &pgsize);
dpfn = pgsize >> PAGE_SHIFT;
- hugeprot = pte_pgprot(pte);
- for (i = 0; i < ncontig; i++, ptep++, addr += pgsize, pfn += dpfn) {
- changed |= ptep_set_access_flags(vma, addr, ptep,
- pfn_pte(pfn, hugeprot), dirty);
- }
+ orig_pte = get_clear_flush(vma->vm_mm, addr, ptep, pgsize, ncontig);
+ if (!pte_same(orig_pte, pte))
+ changed = 1;
+
+ /* Make sure we don't lose the dirty state */
+ if (pte_dirty(orig_pte))
+ pte = pte_mkdirty(pte);
+
+ hugeprot = pte_pgprot(pte);
+ for (i = 0; i < ncontig; i++, ptep++, addr += pgsize, pfn += dpfn)
+ set_pte_at(vma->vm_mm, addr, ptep, pfn_pte(pfn, hugeprot));
return changed;
}
@@ -242,8 +302,11 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma,
void huge_ptep_set_wrprotect(struct mm_struct *mm,
unsigned long addr, pte_t *ptep)
{
+ unsigned long pfn, dpfn;
+ pgprot_t hugeprot;
int ncontig, i;
size_t pgsize;
+ pte_t pte;
if (!pte_cont(*ptep)) {
ptep_set_wrprotect(mm, addr, ptep);
@@ -251,15 +314,23 @@ void huge_ptep_set_wrprotect(struct mm_struct *mm,
}
ncontig = find_num_contig(mm, addr, ptep, &pgsize);
- for (i = 0; i < ncontig; i++, ptep++, addr += pgsize)
- ptep_set_wrprotect(mm, addr, ptep);
+ dpfn = pgsize >> PAGE_SHIFT;
+
+ pte = get_clear_flush(mm, addr, ptep, pgsize, ncontig);
+ pte = pte_wrprotect(pte);
+
+ hugeprot = pte_pgprot(pte);
+ pfn = pte_pfn(pte);
+
+ for (i = 0; i < ncontig; i++, ptep++, addr += pgsize, pfn += dpfn)
+ set_pte_at(mm, addr, ptep, pfn_pte(pfn, hugeprot));
}
void huge_ptep_clear_flush(struct vm_area_struct *vma,
unsigned long addr, pte_t *ptep)
{
- int ncontig, i;
size_t pgsize;
+ int ncontig;
if (!pte_cont(*ptep)) {
ptep_clear_flush(vma, addr, ptep);
@@ -267,8 +338,7 @@ void huge_ptep_clear_flush(struct vm_area_struct *vma,
}
ncontig = find_num_contig(vma->vm_mm, addr, ptep, &pgsize);
- for (i = 0; i < ncontig; i++, ptep++, addr += pgsize)
- ptep_clear_flush(vma, addr, ptep);
+ clear_flush(vma->vm_mm, addr, ptep, pgsize, ncontig);
}
static __init int setup_hugepagesz(char *opt)