228 lines
6.5 KiB
C
228 lines
6.5 KiB
C
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/*
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* IBM System z Huge TLB Page Support for Kernel.
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*
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* Copyright IBM Corp. 2007,2016
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* Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
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*/
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#define KMSG_COMPONENT "hugetlb"
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#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
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#include <linux/mm.h>
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#include <linux/hugetlb.h>
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/*
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* If the bit selected by single-bit bitmask "a" is set within "x", move
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* it to the position indicated by single-bit bitmask "b".
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*/
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#define move_set_bit(x, a, b) (((x) & (a)) >> ilog2(a) << ilog2(b))
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static inline unsigned long __pte_to_rste(pte_t pte)
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{
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unsigned long rste;
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/*
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* Convert encoding pte bits pmd / pud bits
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* lIR.uswrdy.p dy..R...I...wr
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* empty 010.000000.0 -> 00..0...1...00
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* prot-none, clean, old 111.000000.1 -> 00..1...1...00
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* prot-none, clean, young 111.000001.1 -> 01..1...1...00
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* prot-none, dirty, old 111.000010.1 -> 10..1...1...00
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* prot-none, dirty, young 111.000011.1 -> 11..1...1...00
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* read-only, clean, old 111.000100.1 -> 00..1...1...01
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* read-only, clean, young 101.000101.1 -> 01..1...0...01
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* read-only, dirty, old 111.000110.1 -> 10..1...1...01
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* read-only, dirty, young 101.000111.1 -> 11..1...0...01
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* read-write, clean, old 111.001100.1 -> 00..1...1...11
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* read-write, clean, young 101.001101.1 -> 01..1...0...11
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* read-write, dirty, old 110.001110.1 -> 10..0...1...11
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* read-write, dirty, young 100.001111.1 -> 11..0...0...11
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* HW-bits: R read-only, I invalid
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* SW-bits: p present, y young, d dirty, r read, w write, s special,
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* u unused, l large
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*/
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if (pte_present(pte)) {
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rste = pte_val(pte) & PAGE_MASK;
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rste |= move_set_bit(pte_val(pte), _PAGE_READ,
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_SEGMENT_ENTRY_READ);
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rste |= move_set_bit(pte_val(pte), _PAGE_WRITE,
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_SEGMENT_ENTRY_WRITE);
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rste |= move_set_bit(pte_val(pte), _PAGE_INVALID,
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_SEGMENT_ENTRY_INVALID);
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rste |= move_set_bit(pte_val(pte), _PAGE_PROTECT,
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_SEGMENT_ENTRY_PROTECT);
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rste |= move_set_bit(pte_val(pte), _PAGE_DIRTY,
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_SEGMENT_ENTRY_DIRTY);
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rste |= move_set_bit(pte_val(pte), _PAGE_YOUNG,
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_SEGMENT_ENTRY_YOUNG);
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#ifdef CONFIG_MEM_SOFT_DIRTY
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rste |= move_set_bit(pte_val(pte), _PAGE_SOFT_DIRTY,
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_SEGMENT_ENTRY_SOFT_DIRTY);
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#endif
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} else
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rste = _SEGMENT_ENTRY_INVALID;
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return rste;
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}
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static inline pte_t __rste_to_pte(unsigned long rste)
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{
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int present;
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pte_t pte;
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if ((rste & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
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present = pud_present(__pud(rste));
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else
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present = pmd_present(__pmd(rste));
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/*
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* Convert encoding pmd / pud bits pte bits
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* dy..R...I...wr lIR.uswrdy.p
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* empty 00..0...1...00 -> 010.000000.0
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* prot-none, clean, old 00..1...1...00 -> 111.000000.1
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* prot-none, clean, young 01..1...1...00 -> 111.000001.1
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* prot-none, dirty, old 10..1...1...00 -> 111.000010.1
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* prot-none, dirty, young 11..1...1...00 -> 111.000011.1
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* read-only, clean, old 00..1...1...01 -> 111.000100.1
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* read-only, clean, young 01..1...0...01 -> 101.000101.1
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* read-only, dirty, old 10..1...1...01 -> 111.000110.1
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* read-only, dirty, young 11..1...0...01 -> 101.000111.1
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* read-write, clean, old 00..1...1...11 -> 111.001100.1
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* read-write, clean, young 01..1...0...11 -> 101.001101.1
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* read-write, dirty, old 10..0...1...11 -> 110.001110.1
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* read-write, dirty, young 11..0...0...11 -> 100.001111.1
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* HW-bits: R read-only, I invalid
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* SW-bits: p present, y young, d dirty, r read, w write, s special,
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* u unused, l large
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*/
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if (present) {
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pte_val(pte) = rste & _SEGMENT_ENTRY_ORIGIN_LARGE;
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pte_val(pte) |= _PAGE_LARGE | _PAGE_PRESENT;
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pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_READ,
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_PAGE_READ);
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pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_WRITE,
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_PAGE_WRITE);
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pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_INVALID,
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_PAGE_INVALID);
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pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_PROTECT,
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_PAGE_PROTECT);
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pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_DIRTY,
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_PAGE_DIRTY);
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pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_YOUNG,
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_PAGE_YOUNG);
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#ifdef CONFIG_MEM_SOFT_DIRTY
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pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_SOFT_DIRTY,
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_PAGE_SOFT_DIRTY);
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#endif
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} else
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pte_val(pte) = _PAGE_INVALID;
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return pte;
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}
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void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
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pte_t *ptep, pte_t pte)
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{
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unsigned long rste = __pte_to_rste(pte);
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/* Set correct table type for 2G hugepages */
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if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
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rste |= _REGION_ENTRY_TYPE_R3 | _REGION3_ENTRY_LARGE;
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else
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rste |= _SEGMENT_ENTRY_LARGE;
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pte_val(*ptep) = rste;
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}
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pte_t huge_ptep_get(pte_t *ptep)
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{
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return __rste_to_pte(pte_val(*ptep));
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}
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pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
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unsigned long addr, pte_t *ptep)
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{
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pte_t pte = huge_ptep_get(ptep);
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pmd_t *pmdp = (pmd_t *) ptep;
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pud_t *pudp = (pud_t *) ptep;
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if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
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pudp_xchg_direct(mm, addr, pudp, __pud(_REGION3_ENTRY_EMPTY));
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else
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pmdp_xchg_direct(mm, addr, pmdp, __pmd(_SEGMENT_ENTRY_EMPTY));
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return pte;
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}
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pte_t *huge_pte_alloc(struct mm_struct *mm,
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unsigned long addr, unsigned long sz)
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{
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pgd_t *pgdp;
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pud_t *pudp;
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pmd_t *pmdp = NULL;
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pgdp = pgd_offset(mm, addr);
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pudp = pud_alloc(mm, pgdp, addr);
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if (pudp) {
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if (sz == PUD_SIZE)
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return (pte_t *) pudp;
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else if (sz == PMD_SIZE)
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pmdp = pmd_alloc(mm, pudp, addr);
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}
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return (pte_t *) pmdp;
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}
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pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr)
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{
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pgd_t *pgdp;
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pud_t *pudp;
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pmd_t *pmdp = NULL;
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pgdp = pgd_offset(mm, addr);
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if (pgd_present(*pgdp)) {
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pudp = pud_offset(pgdp, addr);
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if (pud_present(*pudp)) {
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if (pud_large(*pudp))
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return (pte_t *) pudp;
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pmdp = pmd_offset(pudp, addr);
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}
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}
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return (pte_t *) pmdp;
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}
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int pmd_huge(pmd_t pmd)
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{
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return pmd_large(pmd);
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}
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int pud_huge(pud_t pud)
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{
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return pud_large(pud);
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}
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struct page *
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follow_huge_pud(struct mm_struct *mm, unsigned long address,
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pud_t *pud, int flags)
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{
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if (flags & FOLL_GET)
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return NULL;
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return pud_page(*pud) + ((address & ~PUD_MASK) >> PAGE_SHIFT);
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}
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static __init int setup_hugepagesz(char *opt)
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{
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unsigned long size;
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char *string = opt;
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size = memparse(opt, &opt);
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if (MACHINE_HAS_EDAT1 && size == PMD_SIZE) {
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hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
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} else if (MACHINE_HAS_EDAT2 && size == PUD_SIZE) {
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hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
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} else {
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hugetlb_bad_size();
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pr_err("hugepagesz= specifies an unsupported page size %s\n",
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string);
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return 0;
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}
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return 1;
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}
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__setup("hugepagesz=", setup_hugepagesz);
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