mm: convert generic code to 5-level paging
Convert all non-architecture-specific code to 5-level paging.
It's mostly mechanical adding handling one more page table level in
places where we deal with pud_t.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/gup.c b/mm/gup.c
index 9c047e9..c74bad1 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -226,6 +226,7 @@
unsigned int *page_mask)
{
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
spinlock_t *ptl;
@@ -243,8 +244,13 @@
pgd = pgd_offset(mm, address);
if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
return no_page_table(vma, flags);
-
- pud = pud_offset(pgd, address);
+ p4d = p4d_offset(pgd, address);
+ if (p4d_none(*p4d))
+ return no_page_table(vma, flags);
+ BUILD_BUG_ON(p4d_huge(*p4d));
+ if (unlikely(p4d_bad(*p4d)))
+ return no_page_table(vma, flags);
+ pud = pud_offset(p4d, address);
if (pud_none(*pud))
return no_page_table(vma, flags);
if (pud_huge(*pud) && vma->vm_flags & VM_HUGETLB) {
@@ -325,6 +331,7 @@
struct page **page)
{
pgd_t *pgd;
+ p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
@@ -338,7 +345,9 @@
else
pgd = pgd_offset_gate(mm, address);
BUG_ON(pgd_none(*pgd));
- pud = pud_offset(pgd, address);
+ p4d = p4d_offset(pgd, address);
+ BUG_ON(p4d_none(*p4d));
+ pud = pud_offset(p4d, address);
BUG_ON(pud_none(*pud));
pmd = pmd_offset(pud, address);
if (pmd_none(*pmd))
@@ -1400,13 +1409,13 @@
return 1;
}
-static int gup_pud_range(pgd_t pgd, unsigned long addr, unsigned long end,
+static int gup_pud_range(p4d_t p4d, unsigned long addr, unsigned long end,
int write, struct page **pages, int *nr)
{
unsigned long next;
pud_t *pudp;
- pudp = pud_offset(&pgd, addr);
+ pudp = pud_offset(&p4d, addr);
do {
pud_t pud = READ_ONCE(*pudp);
@@ -1428,6 +1437,31 @@
return 1;
}
+static int gup_p4d_range(pgd_t pgd, unsigned long addr, unsigned long end,
+ int write, struct page **pages, int *nr)
+{
+ unsigned long next;
+ p4d_t *p4dp;
+
+ p4dp = p4d_offset(&pgd, addr);
+ do {
+ p4d_t p4d = READ_ONCE(*p4dp);
+
+ next = p4d_addr_end(addr, end);
+ if (p4d_none(p4d))
+ return 0;
+ BUILD_BUG_ON(p4d_huge(p4d));
+ if (unlikely(is_hugepd(__hugepd(p4d_val(p4d))))) {
+ if (!gup_huge_pd(__hugepd(p4d_val(p4d)), addr,
+ P4D_SHIFT, next, write, pages, nr))
+ return 0;
+ } else if (!gup_p4d_range(p4d, addr, next, write, pages, nr))
+ return 0;
+ } while (p4dp++, addr = next, addr != end);
+
+ return 1;
+}
+
/*
* Like get_user_pages_fast() except it's IRQ-safe in that it won't fall back to
* the regular GUP. It will only return non-negative values.
@@ -1478,7 +1512,7 @@
if (!gup_huge_pd(__hugepd(pgd_val(pgd)), addr,
PGDIR_SHIFT, next, write, pages, &nr))
break;
- } else if (!gup_pud_range(pgd, addr, next, write, pages, &nr))
+ } else if (!gup_p4d_range(pgd, addr, next, write, pages, &nr))
break;
} while (pgdp++, addr = next, addr != end);
local_irq_restore(flags);