diff options
Diffstat (limited to 'arch/s390/mm/hugetlbpage.c')
| -rw-r--r-- | arch/s390/mm/hugetlbpage.c | 336 |
1 files changed, 336 insertions, 0 deletions
diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c new file mode 100644 index 000000000..c299a1827 --- /dev/null +++ b/arch/s390/mm/hugetlbpage.c @@ -0,0 +1,336 @@ +// 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 <asm/pgalloc.h> +#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) +{ + unsigned long pteval; + int present; + + 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) { + 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 + pteval = _PAGE_INVALID; + return __pte(pteval); +} + +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) { + 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)); +} + +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, 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 (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); +} + +bool __init arch_hugetlb_valid_size(unsigned long size) +{ + if (MACHINE_HAS_EDAT1 && size == PMD_SIZE) + return true; + else if (MACHINE_HAS_EDAT2 && size == PUD_SIZE) + return true; + else + return false; +} + +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); +} |