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