| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * IBM System z Huge TLB Page Support for Kernel. |
| * |
| * Copyright IBM Corp. 2007,2016 |
| * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com> |
| */ |
| |
| #define KMSG_COMPONENT "hugetlb" |
| #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt |
| |
| #include <linux/mm.h> |
| #include <linux/hugetlb.h> |
| |
| /* |
| * 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 |
| rste |= move_set_bit(pte_val(pte), _PAGE_NOEXEC, |
| _SEGMENT_ENTRY_NOEXEC); |
| } else |
| rste = _SEGMENT_ENTRY_EMPTY; |
| 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 |
| pte_val(pte) |= move_set_bit(rste, _SEGMENT_ENTRY_NOEXEC, |
| _PAGE_NOEXEC); |
| } 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; |
| |
| rste = __pte_to_rste(pte); |
| if (!MACHINE_HAS_NX) |
| rste &= ~_SEGMENT_ENTRY_NOEXEC; |
| |
| /* 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; |
| p4d_t *p4dp; |
| pud_t *pudp; |
| pmd_t *pmdp = NULL; |
| |
| pgdp = pgd_offset(mm, addr); |
| p4dp = p4d_alloc(mm, pgdp, addr); |
| if (p4dp) { |
| pudp = pud_alloc(mm, p4dp, 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, unsigned long sz) |
| { |
| pgd_t *pgdp; |
| p4d_t *p4dp; |
| pud_t *pudp; |
| pmd_t *pmdp = NULL; |
| |
| pgdp = pgd_offset(mm, addr); |
| if (pgd_present(*pgdp)) { |
| p4dp = p4d_offset(pgdp, addr); |
| if (p4d_present(*p4dp)) { |
| pudp = pud_offset(p4dp, 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); |
