From 152125b7a882df36a55a8eadbea6d0edf1461ee7 Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Thu, 24 Jul 2014 11:03:41 +0200 Subject: s390/mm: implement dirty bits for large segment table entries The large segment table entry format has block of bits for the ACC/F values for the large page. These bits are valid only if another bit (AV bit 0x10000) of the segment table entry is set. The ACC/F bits do not have a meaning if the AV bit is off. This allows to put the THP splitting bit, the segment young bit and the new segment dirty bit into the ACC/F bits as long as the AV bit stays off. The dirty and young information is only available if the pmd is large. Signed-off-by: Martin Schwidefsky --- arch/s390/include/asm/pgtable.h | 197 ++++++++++++++++++++++------------------ arch/s390/mm/hugetlbpage.c | 103 ++++++++++----------- arch/s390/mm/pgtable.c | 3 + 3 files changed, 159 insertions(+), 144 deletions(-) diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h index fcba5e03839f..b76317c1f3eb 100644 --- a/arch/s390/include/asm/pgtable.h +++ b/arch/s390/include/asm/pgtable.h @@ -287,7 +287,14 @@ extern unsigned long MODULES_END; #define _SEGMENT_ENTRY_INVALID 0x20 /* invalid segment table entry */ #define _SEGMENT_ENTRY_COMMON 0x10 /* common segment bit */ #define _SEGMENT_ENTRY_PTL 0x0f /* page table length */ -#define _SEGMENT_ENTRY_NONE _SEGMENT_ENTRY_PROTECT + +#define _SEGMENT_ENTRY_DIRTY 0 /* No sw dirty bit for 31-bit */ +#define _SEGMENT_ENTRY_YOUNG 0 /* No sw young bit for 31-bit */ +#define _SEGMENT_ENTRY_READ 0 /* No sw read bit for 31-bit */ +#define _SEGMENT_ENTRY_WRITE 0 /* No sw write bit for 31-bit */ +#define _SEGMENT_ENTRY_LARGE 0 /* No large pages for 31-bit */ +#define _SEGMENT_ENTRY_BITS_LARGE 0 +#define _SEGMENT_ENTRY_ORIGIN_LARGE 0 #define _SEGMENT_ENTRY (_SEGMENT_ENTRY_PTL) #define _SEGMENT_ENTRY_EMPTY (_SEGMENT_ENTRY_INVALID) @@ -350,7 +357,7 @@ extern unsigned long MODULES_END; /* Bits in the segment table entry */ #define _SEGMENT_ENTRY_BITS 0xfffffffffffffe33UL -#define _SEGMENT_ENTRY_BITS_LARGE 0xfffffffffff1ff33UL +#define _SEGMENT_ENTRY_BITS_LARGE 0xfffffffffff0ff33UL #define _SEGMENT_ENTRY_ORIGIN_LARGE ~0xfffffUL /* large page address */ #define _SEGMENT_ENTRY_ORIGIN ~0x7ffUL/* segment table origin */ #define _SEGMENT_ENTRY_PROTECT 0x200 /* page protection bit */ @@ -359,30 +366,34 @@ extern unsigned long MODULES_END; #define _SEGMENT_ENTRY (0) #define _SEGMENT_ENTRY_EMPTY (_SEGMENT_ENTRY_INVALID) -#define _SEGMENT_ENTRY_LARGE 0x400 /* STE-format control, large page */ -#define _SEGMENT_ENTRY_CO 0x100 /* change-recording override */ -#define _SEGMENT_ENTRY_SPLIT 0x001 /* THP splitting bit */ -#define _SEGMENT_ENTRY_YOUNG 0x002 /* SW segment young bit */ -#define _SEGMENT_ENTRY_NONE _SEGMENT_ENTRY_YOUNG +#define _SEGMENT_ENTRY_DIRTY 0x2000 /* SW segment dirty bit */ +#define _SEGMENT_ENTRY_YOUNG 0x1000 /* SW segment young bit */ +#define _SEGMENT_ENTRY_SPLIT 0x0800 /* THP splitting bit */ +#define _SEGMENT_ENTRY_LARGE 0x0400 /* STE-format control, large page */ +#define _SEGMENT_ENTRY_CO 0x0100 /* change-recording override */ +#define _SEGMENT_ENTRY_READ 0x0002 /* SW segment read bit */ +#define _SEGMENT_ENTRY_WRITE 0x0001 /* SW segment write bit */ /* * Segment table entry encoding (R = read-only, I = invalid, y = young bit): - * ..R...I...y. - * prot-none, old ..0...1...1. - * prot-none, young ..1...1...1. - * read-only, old ..1...1...0. - * read-only, young ..1...0...1. - * read-write, old ..0...1...0. - * read-write, young ..0...0...1. + * dy..R...I...wr + * prot-none, clean, old 00..1...1...00 + * prot-none, clean, young 01..1...1...00 + * prot-none, dirty, old 10..1...1...00 + * prot-none, dirty, young 11..1...1...00 + * read-only, clean, old 00..1...1...01 + * read-only, clean, young 01..1...0...01 + * read-only, dirty, old 10..1...1...01 + * read-only, dirty, young 11..1...0...01 + * read-write, clean, old 00..1...1...11 + * read-write, clean, young 01..1...0...11 + * read-write, dirty, old 10..0...1...11 + * read-write, dirty, young 11..0...0...11 * The segment table origin is used to distinguish empty (origin==0) from * read-write, old segment table entries (origin!=0) */ -#define _SEGMENT_ENTRY_SPLIT_BIT 0 /* THP splitting bit number */ - -/* Set of bits not changed in pmd_modify */ -#define _SEGMENT_CHG_MASK (_SEGMENT_ENTRY_ORIGIN | _SEGMENT_ENTRY_LARGE \ - | _SEGMENT_ENTRY_SPLIT | _SEGMENT_ENTRY_CO) +#define _SEGMENT_ENTRY_SPLIT_BIT 11 /* THP splitting bit number */ /* Page status table bits for virtualization */ #define PGSTE_ACC_BITS 0xf000000000000000UL @@ -455,10 +466,11 @@ extern unsigned long MODULES_END; * Segment entry (large page) protection definitions. */ #define SEGMENT_NONE __pgprot(_SEGMENT_ENTRY_INVALID | \ - _SEGMENT_ENTRY_NONE) -#define SEGMENT_READ __pgprot(_SEGMENT_ENTRY_INVALID | \ _SEGMENT_ENTRY_PROTECT) -#define SEGMENT_WRITE __pgprot(_SEGMENT_ENTRY_INVALID) +#define SEGMENT_READ __pgprot(_SEGMENT_ENTRY_PROTECT | \ + _SEGMENT_ENTRY_READ) +#define SEGMENT_WRITE __pgprot(_SEGMENT_ENTRY_READ | \ + _SEGMENT_ENTRY_WRITE) static inline int mm_has_pgste(struct mm_struct *mm) { @@ -569,25 +581,23 @@ static inline int pmd_none(pmd_t pmd) static inline int pmd_large(pmd_t pmd) { -#ifdef CONFIG_64BIT return (pmd_val(pmd) & _SEGMENT_ENTRY_LARGE) != 0; -#else - return 0; -#endif } -static inline int pmd_prot_none(pmd_t pmd) +static inline int pmd_pfn(pmd_t pmd) { - return (pmd_val(pmd) & _SEGMENT_ENTRY_INVALID) && - (pmd_val(pmd) & _SEGMENT_ENTRY_NONE); + unsigned long origin_mask; + + origin_mask = _SEGMENT_ENTRY_ORIGIN; + if (pmd_large(pmd)) + origin_mask = _SEGMENT_ENTRY_ORIGIN_LARGE; + return (pmd_val(pmd) & origin_mask) >> PAGE_SHIFT; } static inline int pmd_bad(pmd_t pmd) { -#ifdef CONFIG_64BIT if (pmd_large(pmd)) return (pmd_val(pmd) & ~_SEGMENT_ENTRY_BITS_LARGE) != 0; -#endif return (pmd_val(pmd) & ~_SEGMENT_ENTRY_BITS) != 0; } @@ -607,20 +617,22 @@ extern int pmdp_clear_flush_young(struct vm_area_struct *vma, #define __HAVE_ARCH_PMD_WRITE static inline int pmd_write(pmd_t pmd) { - if (pmd_prot_none(pmd)) - return 0; - return (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT) == 0; + return (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE) != 0; +} + +static inline int pmd_dirty(pmd_t pmd) +{ + int dirty = 1; + if (pmd_large(pmd)) + dirty = (pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY) != 0; + return dirty; } static inline int pmd_young(pmd_t pmd) { - int young = 0; -#ifdef CONFIG_64BIT - if (pmd_prot_none(pmd)) - young = (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT) != 0; - else + int young = 1; + if (pmd_large(pmd)) young = (pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG) != 0; -#endif return young; } @@ -1391,7 +1403,7 @@ static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) #define pte_pfn(x) (pte_val(x) >> PAGE_SHIFT) #define pte_page(x) pfn_to_page(pte_pfn(x)) -#define pmd_page(pmd) pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT) +#define pmd_page(pmd) pfn_to_page(pmd_pfn(pmd)) /* Find an entry in the lowest level page table.. */ #define pte_offset(pmd, addr) ((pte_t *) pmd_deref(*(pmd)) + pte_index(addr)) @@ -1413,41 +1425,75 @@ static inline unsigned long massage_pgprot_pmd(pgprot_t pgprot) return pgprot_val(SEGMENT_WRITE); } -static inline pmd_t pmd_mkyoung(pmd_t pmd) +static inline pmd_t pmd_wrprotect(pmd_t pmd) { -#ifdef CONFIG_64BIT - if (pmd_prot_none(pmd)) { + pmd_val(pmd) &= ~_SEGMENT_ENTRY_WRITE; + pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT; + return pmd; +} + +static inline pmd_t pmd_mkwrite(pmd_t pmd) +{ + pmd_val(pmd) |= _SEGMENT_ENTRY_WRITE; + if (pmd_large(pmd) && !(pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY)) + return pmd; + pmd_val(pmd) &= ~_SEGMENT_ENTRY_PROTECT; + return pmd; +} + +static inline pmd_t pmd_mkclean(pmd_t pmd) +{ + if (pmd_large(pmd)) { + pmd_val(pmd) &= ~_SEGMENT_ENTRY_DIRTY; pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT; - } else { + } + return pmd; +} + +static inline pmd_t pmd_mkdirty(pmd_t pmd) +{ + if (pmd_large(pmd)) { + pmd_val(pmd) |= _SEGMENT_ENTRY_DIRTY; + if (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE) + pmd_val(pmd) &= ~_SEGMENT_ENTRY_PROTECT; + } + return pmd; +} + +static inline pmd_t pmd_mkyoung(pmd_t pmd) +{ + if (pmd_large(pmd)) { pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG; - pmd_val(pmd) &= ~_SEGMENT_ENTRY_INVALID; + if (pmd_val(pmd) & _SEGMENT_ENTRY_READ) + pmd_val(pmd) &= ~_SEGMENT_ENTRY_INVALID; } -#endif return pmd; } static inline pmd_t pmd_mkold(pmd_t pmd) { -#ifdef CONFIG_64BIT - if (pmd_prot_none(pmd)) { - pmd_val(pmd) &= ~_SEGMENT_ENTRY_PROTECT; - } else { + if (pmd_large(pmd)) { pmd_val(pmd) &= ~_SEGMENT_ENTRY_YOUNG; pmd_val(pmd) |= _SEGMENT_ENTRY_INVALID; } -#endif return pmd; } static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) { - int young; - - young = pmd_young(pmd); - pmd_val(pmd) &= _SEGMENT_CHG_MASK; + if (pmd_large(pmd)) { + pmd_val(pmd) &= _SEGMENT_ENTRY_ORIGIN_LARGE | + _SEGMENT_ENTRY_DIRTY | _SEGMENT_ENTRY_YOUNG | + _SEGMENT_ENTRY_LARGE | _SEGMENT_ENTRY_SPLIT; + pmd_val(pmd) |= massage_pgprot_pmd(newprot); + if (!(pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY)) + pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT; + if (!(pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG)) + pmd_val(pmd) |= _SEGMENT_ENTRY_INVALID; + return pmd; + } + pmd_val(pmd) &= _SEGMENT_ENTRY_ORIGIN; pmd_val(pmd) |= massage_pgprot_pmd(newprot); - if (young) - pmd = pmd_mkyoung(pmd); return pmd; } @@ -1455,16 +1501,9 @@ static inline pmd_t mk_pmd_phys(unsigned long physpage, pgprot_t pgprot) { pmd_t __pmd; pmd_val(__pmd) = physpage + massage_pgprot_pmd(pgprot); - return pmd_mkyoung(__pmd); + return __pmd; } -static inline pmd_t pmd_mkwrite(pmd_t pmd) -{ - /* Do not clobber PROT_NONE segments! */ - if (!pmd_prot_none(pmd)) - pmd_val(pmd) &= ~_SEGMENT_ENTRY_PROTECT; - return pmd; -} #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLB_PAGE */ static inline void __pmdp_csp(pmd_t *pmdp) @@ -1555,34 +1594,21 @@ extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp); static inline int pmd_trans_splitting(pmd_t pmd) { - return pmd_val(pmd) & _SEGMENT_ENTRY_SPLIT; + return (pmd_val(pmd) & _SEGMENT_ENTRY_LARGE) && + (pmd_val(pmd) & _SEGMENT_ENTRY_SPLIT); } static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp, pmd_t entry) { - if (!(pmd_val(entry) & _SEGMENT_ENTRY_INVALID) && MACHINE_HAS_EDAT1) - pmd_val(entry) |= _SEGMENT_ENTRY_CO; *pmdp = entry; } static inline pmd_t pmd_mkhuge(pmd_t pmd) { pmd_val(pmd) |= _SEGMENT_ENTRY_LARGE; - return pmd; -} - -static inline pmd_t pmd_wrprotect(pmd_t pmd) -{ - /* Do not clobber PROT_NONE segments! */ - if (!pmd_prot_none(pmd)) - pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT; - return pmd; -} - -static inline pmd_t pmd_mkdirty(pmd_t pmd) -{ - /* No dirty bit in the segment table entry. */ + pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG; + pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT; return pmd; } @@ -1647,11 +1673,6 @@ static inline int has_transparent_hugepage(void) { return MACHINE_HAS_HPAGE ? 1 : 0; } - -static inline unsigned long pmd_pfn(pmd_t pmd) -{ - return pmd_val(pmd) >> PAGE_SHIFT; -} #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ /* diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c index 0ff66a7e29bb..389bc17934b7 100644 --- a/arch/s390/mm/hugetlbpage.c +++ b/arch/s390/mm/hugetlbpage.c @@ -10,42 +10,33 @@ static inline pmd_t __pte_to_pmd(pte_t pte) { - int none, young, prot; pmd_t pmd; /* - * Convert encoding pte bits pmd bits - * .IR...wrdytp ..R...I...y. - * empty .10...000000 -> ..0...1...0. - * prot-none, clean, old .11...000001 -> ..0...1...1. - * prot-none, clean, young .11...000101 -> ..1...1...1. - * prot-none, dirty, old .10...001001 -> ..0...1...1. - * prot-none, dirty, young .10...001101 -> ..1...1...1. - * read-only, clean, old .11...010001 -> ..1...1...0. - * read-only, clean, young .01...010101 -> ..1...0...1. - * read-only, dirty, old .11...011001 -> ..1...1...0. - * read-only, dirty, young .01...011101 -> ..1...0...1. - * read-write, clean, old .11...110001 -> ..0...1...0. - * read-write, clean, young .01...110101 -> ..0...0...1. - * read-write, dirty, old .10...111001 -> ..0...1...0. - * read-write, dirty, young .00...111101 -> ..0...0...1. - * Huge ptes are dirty by definition, a clean pte is made dirty - * by the conversion. + * Convert encoding pte bits pmd bits + * .IR...wrdytp dy..R...I...wr + * empty .10...000000 -> 00..0...1...00 + * prot-none, clean, old .11...000001 -> 00..1...1...00 + * prot-none, clean, young .11...000101 -> 01..1...1...00 + * prot-none, dirty, old .10...001001 -> 10..1...1...00 + * prot-none, dirty, young .10...001101 -> 11..1...1...00 + * read-only, clean, old .11...010001 -> 00..1...1...01 + * read-only, clean, young .01...010101 -> 01..1...0...01 + * read-only, dirty, old .11...011001 -> 10..1...1...01 + * read-only, dirty, young .01...011101 -> 11..1...0...01 + * read-write, clean, old .11...110001 -> 00..0...1...11 + * read-write, clean, young .01...110101 -> 01..0...0...11 + * read-write, dirty, old .10...111001 -> 10..0...1...11 + * read-write, dirty, young .00...111101 -> 11..0...0...11 */ if (pte_present(pte)) { pmd_val(pmd) = pte_val(pte) & PAGE_MASK; - if (pte_val(pte) & _PAGE_INVALID) - pmd_val(pmd) |= _SEGMENT_ENTRY_INVALID; - none = (pte_val(pte) & _PAGE_PRESENT) && - !(pte_val(pte) & _PAGE_READ) && - !(pte_val(pte) & _PAGE_WRITE); - prot = (pte_val(pte) & _PAGE_PROTECT) && - !(pte_val(pte) & _PAGE_WRITE); - young = pte_val(pte) & _PAGE_YOUNG; - if (none || young) - pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG; - if (prot || (none && young)) - pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT; + pmd_val(pmd) |= (pte_val(pte) & _PAGE_READ) >> 4; + pmd_val(pmd) |= (pte_val(pte) & _PAGE_WRITE) >> 4; + pmd_val(pmd) |= (pte_val(pte) & _PAGE_INVALID) >> 5; + pmd_val(pmd) |= (pte_val(pte) & _PAGE_PROTECT); + pmd_val(pmd) |= (pte_val(pte) & _PAGE_DIRTY) << 10; + pmd_val(pmd) |= (pte_val(pte) & _PAGE_YOUNG) << 10; } else pmd_val(pmd) = _SEGMENT_ENTRY_INVALID; return pmd; @@ -56,34 +47,31 @@ static inline pte_t __pmd_to_pte(pmd_t pmd) pte_t pte; /* - * Convert encoding pmd bits pte bits - * ..R...I...y. .IR...wrdytp - * empty ..0...1...0. -> .10...000000 - * prot-none, old ..0...1...1. -> .10...001001 - * prot-none, young ..1...1...1. -> .10...001101 - * read-only, old ..1...1...0. -> .11...011001 - * read-only, young ..1...0...1. -> .01...011101 - * read-write, old ..0...1...0. -> .10...111001 - * read-write, young ..0...0...1. -> .00...111101 - * Huge ptes are dirty by definition + * Convert encoding pmd bits pte bits + * dy..R...I...wr .IR...wrdytp + * empty 00..0...1...00 -> .10...001100 + * prot-none, clean, old 00..0...1...00 -> .10...000001 + * prot-none, clean, young 01..0...1...00 -> .10...000101 + * prot-none, dirty, old 10..0...1...00 -> .10...001001 + * prot-none, dirty, young 11..0...1...00 -> .10...001101 + * read-only, clean, old 00..1...1...01 -> .11...010001 + * read-only, clean, young 01..1...1...01 -> .11...010101 + * read-only, dirty, old 10..1...1...01 -> .11...011001 + * read-only, dirty, young 11..1...1...01 -> .11...011101 + * read-write, clean, old 00..0...1...11 -> .10...110001 + * read-write, clean, young 01..0...1...11 -> .10...110101 + * read-write, dirty, old 10..0...1...11 -> .10...111001 + * read-write, dirty, young 11..0...1...11 -> .10...111101 */ if (pmd_present(pmd)) { - pte_val(pte) = _PAGE_PRESENT | _PAGE_LARGE | _PAGE_DIRTY | - (pmd_val(pmd) & PAGE_MASK); - if (pmd_val(pmd) & _SEGMENT_ENTRY_INVALID) - pte_val(pte) |= _PAGE_INVALID; - if (pmd_prot_none(pmd)) { - if (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT) - pte_val(pte) |= _PAGE_YOUNG; - } else { - pte_val(pte) |= _PAGE_READ; - if (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT) - pte_val(pte) |= _PAGE_PROTECT; - else - pte_val(pte) |= _PAGE_WRITE; - if (pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG) - pte_val(pte) |= _PAGE_YOUNG; - } + pte_val(pte) = pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN_LARGE; + pte_val(pte) |= _PAGE_LARGE | _PAGE_PRESENT; + pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_READ) << 4; + pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE) << 4; + pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_INVALID) << 5; + pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT); + pmd_val(pmd) |= (pte_val(pte) & _PAGE_DIRTY) << 10; + pmd_val(pmd) |= (pte_val(pte) & _PAGE_YOUNG) << 10; } else pte_val(pte) = _PAGE_INVALID; return pte; @@ -96,6 +84,7 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pmd = __pte_to_pmd(pte); if (!MACHINE_HAS_HPAGE) { + /* Emulated huge ptes loose the dirty and young bit */ pmd_val(pmd) &= ~_SEGMENT_ENTRY_ORIGIN; pmd_val(pmd) |= pte_page(pte)[1].index; } else @@ -113,6 +102,8 @@ pte_t huge_ptep_get(pte_t *ptep) origin = pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN; pmd_val(pmd) &= ~_SEGMENT_ENTRY_ORIGIN; pmd_val(pmd) |= *(unsigned long *) origin; + /* Emulated huge ptes are young and dirty by definition */ + pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG | _SEGMENT_ENTRY_DIRTY; } return __pmd_to_pte(pmd); } diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index f90ad8592b36..19daa53a3da4 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -1433,6 +1433,9 @@ int pmdp_set_access_flags(struct vm_area_struct *vma, { VM_BUG_ON(address & ~HPAGE_PMD_MASK); + entry = pmd_mkyoung(entry); + if (dirty) + entry = pmd_mkdirty(entry); if (pmd_same(*pmdp, entry)) return 0; pmdp_invalidate(vma, address, pmdp); -- cgit v1.2.3-59-g8ed1b