| // 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/mm.h> |
| #include <linux/hugetlb.h> |
| #include <linux/mman.h> |
| #include <linux/sched/mm.h> |
| #include <linux/security.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; |
| } |
| |
| static void clear_huge_pte_skeys(struct mm_struct *mm, unsigned long rste) |
| { |
| struct page *page; |
| unsigned long size, paddr; |
| |
| if (!mm_uses_skeys(mm) || |
| rste & _SEGMENT_ENTRY_INVALID) |
| return; |
| |
| if ((rste & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) { |
| page = pud_page(__pud(rste)); |
| size = PUD_SIZE; |
| paddr = rste & PUD_MASK; |
| } else { |
| page = pmd_page(__pmd(rste)); |
| size = PMD_SIZE; |
| paddr = rste & PMD_MASK; |
| } |
| |
| if (!test_and_set_bit(PG_arch_1, &page->flags)) |
| __storage_key_init_range(paddr, paddr + size - 1); |
| } |
| |
| 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; |
| clear_huge_pte_skeys(mm, rste); |
| 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); |
| |
| static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file, |
| unsigned long addr, unsigned long len, |
| unsigned long pgoff, unsigned long flags) |
| { |
| struct hstate *h = hstate_file(file); |
| struct vm_unmapped_area_info info; |
| |
| info.flags = 0; |
| info.length = len; |
| info.low_limit = current->mm->mmap_base; |
| info.high_limit = TASK_SIZE; |
| info.align_mask = PAGE_MASK & ~huge_page_mask(h); |
| info.align_offset = 0; |
| return vm_unmapped_area(&info); |
| } |
| |
| static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file, |
| unsigned long addr0, unsigned long len, |
| unsigned long pgoff, unsigned long flags) |
| { |
| struct hstate *h = hstate_file(file); |
| struct vm_unmapped_area_info info; |
| unsigned long addr; |
| |
| info.flags = VM_UNMAPPED_AREA_TOPDOWN; |
| info.length = len; |
| info.low_limit = max(PAGE_SIZE, mmap_min_addr); |
| info.high_limit = current->mm->mmap_base; |
| info.align_mask = PAGE_MASK & ~huge_page_mask(h); |
| info.align_offset = 0; |
| addr = vm_unmapped_area(&info); |
| |
| /* |
| * A failed mmap() very likely causes application failure, |
| * so fall back to the bottom-up function here. This scenario |
| * can happen with large stack limits and large mmap() |
| * allocations. |
| */ |
| if (addr & ~PAGE_MASK) { |
| VM_BUG_ON(addr != -ENOMEM); |
| info.flags = 0; |
| info.low_limit = TASK_UNMAPPED_BASE; |
| info.high_limit = TASK_SIZE; |
| addr = vm_unmapped_area(&info); |
| } |
| |
| return addr; |
| } |
| |
| unsigned long hugetlb_get_unmapped_area(struct file *file, unsigned long addr, |
| unsigned long len, unsigned long pgoff, unsigned long flags) |
| { |
| struct hstate *h = hstate_file(file); |
| struct mm_struct *mm = current->mm; |
| struct vm_area_struct *vma; |
| |
| if (len & ~huge_page_mask(h)) |
| return -EINVAL; |
| if (len > TASK_SIZE - mmap_min_addr) |
| return -ENOMEM; |
| |
| if (flags & MAP_FIXED) { |
| if (prepare_hugepage_range(file, addr, len)) |
| return -EINVAL; |
| goto check_asce_limit; |
| } |
| |
| if (addr) { |
| addr = ALIGN(addr, huge_page_size(h)); |
| vma = find_vma(mm, addr); |
| if (TASK_SIZE - len >= addr && addr >= mmap_min_addr && |
| (!vma || addr + len <= vm_start_gap(vma))) |
| goto check_asce_limit; |
| } |
| |
| if (mm->get_unmapped_area == arch_get_unmapped_area) |
| addr = hugetlb_get_unmapped_area_bottomup(file, addr, len, |
| pgoff, flags); |
| else |
| addr = hugetlb_get_unmapped_area_topdown(file, addr, len, |
| pgoff, flags); |
| if (offset_in_page(addr)) |
| return addr; |
| |
| check_asce_limit: |
| return check_asce_limit(mm, addr, len); |
| } |
