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author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-03-10 17:59:07 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-03-10 17:59:07 +0100 |
commit | baeedc7158da5b0f489d04125ba6adfba532a6f7 (patch) | |
tree | 1f42b5cd4a961ed10673578a28602dd13d09ab99 /mm/huge_memory.c | |
parent | Merge branch 'akpm' (patches from Andrew) (diff) | |
parent | mm: introduce __p4d_alloc() (diff) | |
download | linux-baeedc7158da5b0f489d04125ba6adfba532a6f7.tar.xz linux-baeedc7158da5b0f489d04125ba6adfba532a6f7.zip |
Merge branch 'prep-for-5level'
Merge 5-level page table prep from Kirill Shutemov:
"Here's relatively low-risk part of 5-level paging patchset. Merging it
now will make x86 5-level paging enabling in v4.12 easier.
The first patch is actually x86-specific: detect 5-level paging
support. It boils down to single define.
The rest of patchset converts Linux MMU abstraction from 4- to 5-level
paging.
Enabling of new abstraction in most cases requires adding single line
of code in arch-specific code. The rest is taken care by asm-generic/.
Changes to mm/ code are mostly mechanical: add support for new page
table level -- p4d_t -- where we deal with pud_t now.
v2:
- fix build on microblaze (Michal);
- comment for __ARCH_HAS_5LEVEL_HACK in kasan_populate_zero_shadow();
- acks from Michal"
* emailed patches from Kirill A Shutemov <kirill.shutemov@linux.intel.com>:
mm: introduce __p4d_alloc()
mm: convert generic code to 5-level paging
asm-generic: introduce <asm-generic/pgtable-nop4d.h>
arch, mm: convert all architectures to use 5level-fixup.h
asm-generic: introduce __ARCH_USE_5LEVEL_HACK
asm-generic: introduce 5level-fixup.h
x86/cpufeature: Add 5-level paging detection
Diffstat (limited to 'mm/huge_memory.c')
-rw-r--r-- | mm/huge_memory.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 8f037e256c54..1ebc93e179f3 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2048,6 +2048,7 @@ void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address, bool freeze, struct page *page) { pgd_t *pgd; + p4d_t *p4d; pud_t *pud; pmd_t *pmd; @@ -2055,7 +2056,11 @@ void split_huge_pmd_address(struct vm_area_struct *vma, unsigned long address, if (!pgd_present(*pgd)) return; - pud = pud_offset(pgd, address); + p4d = p4d_offset(pgd, address); + if (!p4d_present(*p4d)) + return; + + pud = pud_offset(p4d, address); if (!pud_present(*pud)) return; |