diff options
Diffstat (limited to 'arch/x86/mm/hugetlbpage.c')
| -rw-r--r-- | arch/x86/mm/hugetlbpage.c | 203 |
1 files changed, 203 insertions, 0 deletions
diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c new file mode 100644 index 000000000..a0d023cb4 --- /dev/null +++ b/arch/x86/mm/hugetlbpage.c @@ -0,0 +1,203 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * IA-32 Huge TLB Page Support for Kernel. + * + * Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com> + */ + +#include <linux/init.h> +#include <linux/fs.h> +#include <linux/mm.h> +#include <linux/sched/mm.h> +#include <linux/hugetlb.h> +#include <linux/pagemap.h> +#include <linux/err.h> +#include <linux/sysctl.h> +#include <linux/compat.h> +#include <asm/mman.h> +#include <asm/tlb.h> +#include <asm/tlbflush.h> +#include <asm/elf.h> + +#if 0 /* This is just for testing */ +struct page * +follow_huge_addr(struct mm_struct *mm, unsigned long address, int write) +{ + unsigned long start = address; + int length = 1; + int nr; + struct page *page; + struct vm_area_struct *vma; + + vma = find_vma(mm, addr); + if (!vma || !is_vm_hugetlb_page(vma)) + return ERR_PTR(-EINVAL); + + pte = huge_pte_offset(mm, address, vma_mmu_pagesize(vma)); + + /* hugetlb should be locked, and hence, prefaulted */ + WARN_ON(!pte || pte_none(*pte)); + + page = &pte_page(*pte)[vpfn % (HPAGE_SIZE/PAGE_SIZE)]; + + WARN_ON(!PageHead(page)); + + return page; +} + +int pmd_huge(pmd_t pmd) +{ + return 0; +} + +int pud_huge(pud_t pud) +{ + return 0; +} + +#else + +/* + * pmd_huge() returns 1 if @pmd is hugetlb related entry, that is normal + * hugetlb entry or non-present (migration or hwpoisoned) hugetlb entry. + * Otherwise, returns 0. + */ +int pmd_huge(pmd_t pmd) +{ + return !pmd_none(pmd) && + (pmd_val(pmd) & (_PAGE_PRESENT|_PAGE_PSE)) != _PAGE_PRESENT; +} + +int pud_huge(pud_t pud) +{ + return !!(pud_val(pud) & _PAGE_PSE); +} +#endif + +#ifdef CONFIG_HUGETLB_PAGE +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 = get_mmap_base(1); + + /* + * If hint address is above DEFAULT_MAP_WINDOW, look for unmapped area + * in the full address space. + */ + info.high_limit = in_32bit_syscall() ? + task_size_32bit() : task_size_64bit(addr > DEFAULT_MAP_WINDOW); + + 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 addr, unsigned long len, + unsigned long pgoff, unsigned long flags) +{ + struct hstate *h = hstate_file(file); + struct vm_unmapped_area_info info; + + info.flags = VM_UNMAPPED_AREA_TOPDOWN; + info.length = len; + info.low_limit = PAGE_SIZE; + info.high_limit = get_mmap_base(0); + + /* + * If hint address is above DEFAULT_MAP_WINDOW, look for unmapped area + * in the full address space. + */ + if (addr > DEFAULT_MAP_WINDOW && !in_32bit_syscall()) + info.high_limit += TASK_SIZE_MAX - DEFAULT_MAP_WINDOW; + + 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_LOW; + 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) + return -ENOMEM; + + /* No address checking. See comment at mmap_address_hint_valid() */ + if (flags & MAP_FIXED) { + if (prepare_hugepage_range(file, addr, len)) + return -EINVAL; + return addr; + } + + if (addr) { + addr &= huge_page_mask(h); + if (!mmap_address_hint_valid(addr, len)) + goto get_unmapped_area; + + vma = find_vma(mm, addr); + if (!vma || addr + len <= vm_start_gap(vma)) + return addr; + } + +get_unmapped_area: + if (mm->get_unmapped_area == arch_get_unmapped_area) + return hugetlb_get_unmapped_area_bottomup(file, addr, len, + pgoff, flags); + else + return hugetlb_get_unmapped_area_topdown(file, addr, len, + pgoff, flags); +} +#endif /* CONFIG_HUGETLB_PAGE */ + +#ifdef CONFIG_X86_64 +bool __init arch_hugetlb_valid_size(unsigned long size) +{ + if (size == PMD_SIZE) + return true; + else if (size == PUD_SIZE && boot_cpu_has(X86_FEATURE_GBPAGES)) + return true; + else + return false; +} + +#ifdef CONFIG_CONTIG_ALLOC +static __init int gigantic_pages_init(void) +{ + /* With compaction or CMA we can allocate gigantic pages at runtime */ + if (boot_cpu_has(X86_FEATURE_GBPAGES)) + hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT); + return 0; +} +arch_initcall(gigantic_pages_init); +#endif +#endif |