151 lines
4.4 KiB
C
151 lines
4.4 KiB
C
/*
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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
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* Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
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*/
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#include <linux/mm.h>
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#include <linux/hugetlb.h>
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static inline pmd_t __pte_to_pmd(pte_t pte)
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{
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pmd_t pmd;
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/*
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* Convert encoding pte bits pmd 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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pmd_val(pmd) = pte_val(pte) & PAGE_MASK;
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pmd_val(pmd) |= (pte_val(pte) & _PAGE_READ) >> 4;
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pmd_val(pmd) |= (pte_val(pte) & _PAGE_WRITE) >> 4;
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pmd_val(pmd) |= (pte_val(pte) & _PAGE_INVALID) >> 5;
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pmd_val(pmd) |= (pte_val(pte) & _PAGE_PROTECT);
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pmd_val(pmd) |= (pte_val(pte) & _PAGE_DIRTY) << 10;
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pmd_val(pmd) |= (pte_val(pte) & _PAGE_YOUNG) << 10;
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} else
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pmd_val(pmd) = _SEGMENT_ENTRY_INVALID;
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return pmd;
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}
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static inline pte_t __pmd_to_pte(pmd_t pmd)
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{
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pte_t pte;
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/*
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* Convert encoding pmd 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 (pmd_present(pmd)) {
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pte_val(pte) = pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN_LARGE;
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pte_val(pte) |= _PAGE_LARGE | _PAGE_PRESENT;
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pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_READ) << 4;
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pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_WRITE) << 4;
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pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_INVALID) << 5;
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pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT);
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pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_DIRTY) >> 10;
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pte_val(pte) |= (pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG) >> 10;
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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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pmd_t pmd = __pte_to_pmd(pte);
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pmd_val(pmd) |= _SEGMENT_ENTRY_LARGE;
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*(pmd_t *) ptep = pmd;
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}
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pte_t huge_ptep_get(pte_t *ptep)
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{
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pmd_t pmd = *(pmd_t *) ptep;
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return __pmd_to_pte(pmd);
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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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pmd_t *pmdp = (pmd_t *) ptep;
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pte_t pte = huge_ptep_get(ptep);
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pmdp_flush_direct(mm, addr, pmdp);
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pmd_val(*pmdp) = _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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pmdp = pmd_alloc(mm, pudp, addr);
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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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pmdp = pmd_offset(pudp, addr);
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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 0;
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}
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