| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * IBM System z Huge TLB Page Support for Kernel. |
| * |
| * Copyright IBM Corp. 2007,2020 |
| * Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com> |
| */ |
| |
| #define KMSG_COMPONENT "hugetlb" |
| #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt |
| |
| #include <linux/cpufeature.h> |
| #include <linux/mm.h> |
| #include <linux/hugetlb.h> |
| #include <linux/mman.h> |
| #include <linux/sched/mm.h> |
| #include <linux/security.h> |
| #include <asm/pgalloc.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) |
| { |
| swp_entry_t arch_entry; |
| 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 |= _SEGMENT_ENTRY_PRESENT; |
| 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 if (!pte_none(pte)) { |
| /* swap pte */ |
| arch_entry = __pte_to_swp_entry(pte); |
| rste = mk_swap_rste(__swp_type(arch_entry), __swp_offset(arch_entry)); |
| } else |
| rste = _SEGMENT_ENTRY_EMPTY; |
| return rste; |
| } |
| |
| static inline pte_t __rste_to_pte(unsigned long rste) |
| { |
| swp_entry_t arch_entry; |
| unsigned long pteval; |
| int present, none; |
| pte_t pte; |
| |
| if ((rste & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) { |
| present = pud_present(__pud(rste)); |
| none = pud_none(__pud(rste)); |
| } else { |
| present = pmd_present(__pmd(rste)); |
| none = pmd_none(__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) { |
| pteval = rste & _SEGMENT_ENTRY_ORIGIN_LARGE; |
| pteval |= _PAGE_LARGE | _PAGE_PRESENT; |
| pteval |= move_set_bit(rste, _SEGMENT_ENTRY_READ, _PAGE_READ); |
| pteval |= move_set_bit(rste, _SEGMENT_ENTRY_WRITE, _PAGE_WRITE); |
| pteval |= move_set_bit(rste, _SEGMENT_ENTRY_INVALID, _PAGE_INVALID); |
| pteval |= move_set_bit(rste, _SEGMENT_ENTRY_PROTECT, _PAGE_PROTECT); |
| pteval |= move_set_bit(rste, _SEGMENT_ENTRY_DIRTY, _PAGE_DIRTY); |
| pteval |= move_set_bit(rste, _SEGMENT_ENTRY_YOUNG, _PAGE_YOUNG); |
| #ifdef CONFIG_MEM_SOFT_DIRTY |
| pteval |= move_set_bit(rste, _SEGMENT_ENTRY_SOFT_DIRTY, _PAGE_SOFT_DIRTY); |
| #endif |
| pteval |= move_set_bit(rste, _SEGMENT_ENTRY_NOEXEC, _PAGE_NOEXEC); |
| } else if (!none) { |
| /* swap rste */ |
| arch_entry = __rste_to_swp_entry(rste); |
| pte = mk_swap_pte(__swp_type_rste(arch_entry), __swp_offset_rste(arch_entry)); |
| pteval = pte_val(pte); |
| } else |
| pteval = _PAGE_INVALID; |
| return __pte(pteval); |
| } |
| |
| static void clear_huge_pte_skeys(struct mm_struct *mm, unsigned long rste) |
| { |
| struct folio *folio; |
| unsigned long size, paddr; |
| |
| if (!mm_uses_skeys(mm) || |
| rste & _SEGMENT_ENTRY_INVALID) |
| return; |
| |
| if ((rste & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) { |
| folio = page_folio(pud_page(__pud(rste))); |
| size = PUD_SIZE; |
| paddr = rste & PUD_MASK; |
| } else { |
| folio = page_folio(pmd_page(__pmd(rste))); |
| size = PMD_SIZE; |
| paddr = rste & PMD_MASK; |
| } |
| |
| if (!test_and_set_bit(PG_arch_1, &folio->flags)) |
| __storage_key_init_range(paddr, paddr + size); |
| } |
| |
| 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); |
| |
| /* Set correct table type for 2G hugepages */ |
| if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) { |
| if (likely(pte_present(pte))) |
| rste |= _REGION3_ENTRY_LARGE; |
| rste |= _REGION_ENTRY_TYPE_R3; |
| } else if (likely(pte_present(pte))) |
| rste |= _SEGMENT_ENTRY_LARGE; |
| |
| clear_huge_pte_skeys(mm, rste); |
| set_pte(ptep, __pte(rste)); |
| } |
| |
| void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, |
| pte_t *ptep, pte_t pte, unsigned long sz) |
| { |
| __set_huge_pte_at(mm, addr, ptep, pte); |
| } |
| |
| pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, 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(mm, addr, 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, struct vm_area_struct *vma, |
| 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 (sz == PUD_SIZE) |
| return (pte_t *)pudp; |
| if (pud_present(*pudp)) |
| pmdp = pmd_offset(pudp, addr); |
| } |
| } |
| return (pte_t *) pmdp; |
| } |
| |
| bool __init arch_hugetlb_valid_size(unsigned long size) |
| { |
| if (cpu_has_edat1() && size == PMD_SIZE) |
| return true; |
| else if (cpu_has_edat2() && size == PUD_SIZE) |
| return true; |
| else |
| return false; |
| } |
