559 lines
13 KiB
C
559 lines
13 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* arch/arm64/mm/hugetlbpage.c
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*
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* Copyright (C) 2013 Linaro Ltd.
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*
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* Based on arch/x86/mm/hugetlbpage.c.
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*/
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#include <linux/init.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/hugetlb.h>
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#include <linux/pagemap.h>
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#include <linux/err.h>
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#include <linux/sysctl.h>
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#include <asm/mman.h>
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#include <asm/tlb.h>
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#include <asm/tlbflush.h>
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/*
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* HugeTLB Support Matrix
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*
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* ---------------------------------------------------
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* | Page Size | CONT PTE | PMD | CONT PMD | PUD |
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* ---------------------------------------------------
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* | 4K | 64K | 2M | 32M | 1G |
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* | 16K | 2M | 32M | 1G | |
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* | 64K | 2M | 512M | 16G | |
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* ---------------------------------------------------
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*/
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/*
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* Reserve CMA areas for the largest supported gigantic
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* huge page when requested. Any other smaller gigantic
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* huge pages could still be served from those areas.
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*/
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#ifdef CONFIG_CMA
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void __init arm64_hugetlb_cma_reserve(void)
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{
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int order;
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if (pud_sect_supported())
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order = PUD_SHIFT - PAGE_SHIFT;
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else
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order = CONT_PMD_SHIFT - PAGE_SHIFT;
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hugetlb_cma_reserve(order);
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}
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#endif /* CONFIG_CMA */
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static bool __hugetlb_valid_size(unsigned long size)
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{
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switch (size) {
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#ifndef __PAGETABLE_PMD_FOLDED
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case PUD_SIZE:
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return pud_sect_supported();
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#endif
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case CONT_PMD_SIZE:
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case PMD_SIZE:
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case CONT_PTE_SIZE:
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return true;
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}
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return false;
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}
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#ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
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bool arch_hugetlb_migration_supported(struct hstate *h)
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{
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size_t pagesize = huge_page_size(h);
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if (!__hugetlb_valid_size(pagesize)) {
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pr_warn("%s: unrecognized huge page size 0x%lx\n",
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__func__, pagesize);
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return false;
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}
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return true;
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}
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#endif
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int pmd_huge(pmd_t pmd)
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{
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return pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT);
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}
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int pud_huge(pud_t pud)
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{
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#ifndef __PAGETABLE_PMD_FOLDED
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return pud_val(pud) && !(pud_val(pud) & PUD_TABLE_BIT);
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#else
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return 0;
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#endif
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}
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static int find_num_contig(struct mm_struct *mm, unsigned long addr,
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pte_t *ptep, size_t *pgsize)
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{
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pgd_t *pgdp = pgd_offset(mm, addr);
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p4d_t *p4dp;
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pud_t *pudp;
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pmd_t *pmdp;
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*pgsize = PAGE_SIZE;
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p4dp = p4d_offset(pgdp, addr);
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pudp = pud_offset(p4dp, addr);
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pmdp = pmd_offset(pudp, addr);
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if ((pte_t *)pmdp == ptep) {
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*pgsize = PMD_SIZE;
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return CONT_PMDS;
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}
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return CONT_PTES;
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}
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static inline int num_contig_ptes(unsigned long size, size_t *pgsize)
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{
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int contig_ptes = 0;
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*pgsize = size;
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switch (size) {
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#ifndef __PAGETABLE_PMD_FOLDED
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case PUD_SIZE:
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if (pud_sect_supported())
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contig_ptes = 1;
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break;
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#endif
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case PMD_SIZE:
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contig_ptes = 1;
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break;
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case CONT_PMD_SIZE:
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*pgsize = PMD_SIZE;
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contig_ptes = CONT_PMDS;
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break;
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case CONT_PTE_SIZE:
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*pgsize = PAGE_SIZE;
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contig_ptes = CONT_PTES;
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break;
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}
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return contig_ptes;
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}
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pte_t huge_ptep_get(pte_t *ptep)
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{
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int ncontig, i;
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size_t pgsize;
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pte_t orig_pte = __ptep_get(ptep);
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if (!pte_present(orig_pte) || !pte_cont(orig_pte))
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return orig_pte;
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ncontig = num_contig_ptes(page_size(pte_page(orig_pte)), &pgsize);
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for (i = 0; i < ncontig; i++, ptep++) {
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pte_t pte = __ptep_get(ptep);
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if (pte_dirty(pte))
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orig_pte = pte_mkdirty(orig_pte);
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if (pte_young(pte))
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orig_pte = pte_mkyoung(orig_pte);
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}
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return orig_pte;
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}
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/*
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* Changing some bits of contiguous entries requires us to follow a
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* Break-Before-Make approach, breaking the whole contiguous set
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* before we can change any entries. See ARM DDI 0487A.k_iss10775,
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* "Misprogramming of the Contiguous bit", page D4-1762.
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*
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* This helper performs the break step.
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*/
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static pte_t get_clear_contig(struct mm_struct *mm,
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unsigned long addr,
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pte_t *ptep,
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unsigned long pgsize,
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unsigned long ncontig)
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{
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pte_t orig_pte = __ptep_get(ptep);
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unsigned long i;
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for (i = 0; i < ncontig; i++, addr += pgsize, ptep++) {
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pte_t pte = __ptep_get_and_clear(mm, addr, ptep);
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/*
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* If HW_AFDBM is enabled, then the HW could turn on
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* the dirty or accessed bit for any page in the set,
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* so check them all.
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*/
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if (pte_dirty(pte))
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orig_pte = pte_mkdirty(orig_pte);
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if (pte_young(pte))
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orig_pte = pte_mkyoung(orig_pte);
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}
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return orig_pte;
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}
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static pte_t get_clear_contig_flush(struct mm_struct *mm,
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unsigned long addr,
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pte_t *ptep,
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unsigned long pgsize,
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unsigned long ncontig)
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{
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pte_t orig_pte = get_clear_contig(mm, addr, ptep, pgsize, ncontig);
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struct vm_area_struct vma = TLB_FLUSH_VMA(mm, 0);
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flush_tlb_range(&vma, addr, addr + (pgsize * ncontig));
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return orig_pte;
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}
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/*
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* Changing some bits of contiguous entries requires us to follow a
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* Break-Before-Make approach, breaking the whole contiguous set
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* before we can change any entries. See ARM DDI 0487A.k_iss10775,
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* "Misprogramming of the Contiguous bit", page D4-1762.
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*
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* This helper performs the break step for use cases where the
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* original pte is not needed.
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*/
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static void clear_flush(struct mm_struct *mm,
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unsigned long addr,
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pte_t *ptep,
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unsigned long pgsize,
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unsigned long ncontig)
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{
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struct vm_area_struct vma = TLB_FLUSH_VMA(mm, 0);
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unsigned long i, saddr = addr;
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for (i = 0; i < ncontig; i++, addr += pgsize, ptep++)
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__ptep_get_and_clear(mm, addr, ptep);
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flush_tlb_range(&vma, saddr, addr);
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}
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void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
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pte_t *ptep, pte_t pte, unsigned long sz)
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{
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size_t pgsize;
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int i;
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int ncontig;
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unsigned long pfn, dpfn;
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pgprot_t hugeprot;
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ncontig = num_contig_ptes(sz, &pgsize);
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if (!pte_present(pte)) {
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for (i = 0; i < ncontig; i++, ptep++, addr += pgsize)
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__set_ptes(mm, addr, ptep, pte, 1);
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return;
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}
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if (!pte_cont(pte)) {
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__set_ptes(mm, addr, ptep, pte, 1);
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return;
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}
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pfn = pte_pfn(pte);
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dpfn = pgsize >> PAGE_SHIFT;
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hugeprot = pte_pgprot(pte);
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clear_flush(mm, addr, ptep, pgsize, ncontig);
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for (i = 0; i < ncontig; i++, ptep++, addr += pgsize, pfn += dpfn)
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__set_ptes(mm, addr, ptep, pfn_pte(pfn, hugeprot), 1);
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}
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pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
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unsigned long addr, unsigned long sz)
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{
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pgd_t *pgdp;
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p4d_t *p4dp;
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pud_t *pudp;
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pmd_t *pmdp;
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pte_t *ptep = NULL;
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pgdp = pgd_offset(mm, addr);
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p4dp = p4d_offset(pgdp, addr);
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pudp = pud_alloc(mm, p4dp, addr);
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if (!pudp)
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return NULL;
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if (sz == PUD_SIZE) {
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ptep = (pte_t *)pudp;
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} else if (sz == (CONT_PTE_SIZE)) {
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pmdp = pmd_alloc(mm, pudp, addr);
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if (!pmdp)
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return NULL;
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WARN_ON(addr & (sz - 1));
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ptep = pte_alloc_huge(mm, pmdp, addr);
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} else if (sz == PMD_SIZE) {
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if (want_pmd_share(vma, addr) && pud_none(READ_ONCE(*pudp)))
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ptep = huge_pmd_share(mm, vma, addr, pudp);
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else
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ptep = (pte_t *)pmd_alloc(mm, pudp, addr);
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} else if (sz == (CONT_PMD_SIZE)) {
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pmdp = pmd_alloc(mm, pudp, addr);
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WARN_ON(addr & (sz - 1));
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return (pte_t *)pmdp;
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}
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return ptep;
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}
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pte_t *huge_pte_offset(struct mm_struct *mm,
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unsigned long addr, unsigned long sz)
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{
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pgd_t *pgdp;
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p4d_t *p4dp;
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pud_t *pudp, pud;
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pmd_t *pmdp, pmd;
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pgdp = pgd_offset(mm, addr);
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if (!pgd_present(READ_ONCE(*pgdp)))
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return NULL;
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p4dp = p4d_offset(pgdp, addr);
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if (!p4d_present(READ_ONCE(*p4dp)))
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return NULL;
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pudp = pud_offset(p4dp, addr);
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pud = READ_ONCE(*pudp);
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if (sz != PUD_SIZE && pud_none(pud))
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return NULL;
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/* hugepage or swap? */
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if (pud_huge(pud) || !pud_present(pud))
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return (pte_t *)pudp;
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/* table; check the next level */
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if (sz == CONT_PMD_SIZE)
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addr &= CONT_PMD_MASK;
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pmdp = pmd_offset(pudp, addr);
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pmd = READ_ONCE(*pmdp);
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if (!(sz == PMD_SIZE || sz == CONT_PMD_SIZE) &&
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pmd_none(pmd))
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return NULL;
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if (pmd_huge(pmd) || !pmd_present(pmd))
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return (pte_t *)pmdp;
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if (sz == CONT_PTE_SIZE)
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return pte_offset_huge(pmdp, (addr & CONT_PTE_MASK));
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return NULL;
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}
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unsigned long hugetlb_mask_last_page(struct hstate *h)
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{
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unsigned long hp_size = huge_page_size(h);
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switch (hp_size) {
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#ifndef __PAGETABLE_PMD_FOLDED
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case PUD_SIZE:
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return PGDIR_SIZE - PUD_SIZE;
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#endif
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case CONT_PMD_SIZE:
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return PUD_SIZE - CONT_PMD_SIZE;
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case PMD_SIZE:
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return PUD_SIZE - PMD_SIZE;
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case CONT_PTE_SIZE:
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return PMD_SIZE - CONT_PTE_SIZE;
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default:
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break;
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}
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return 0UL;
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}
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pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags)
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{
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size_t pagesize = 1UL << shift;
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entry = pte_mkhuge(entry);
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if (pagesize == CONT_PTE_SIZE) {
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entry = pte_mkcont(entry);
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} else if (pagesize == CONT_PMD_SIZE) {
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entry = pmd_pte(pmd_mkcont(pte_pmd(entry)));
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} else if (pagesize != PUD_SIZE && pagesize != PMD_SIZE) {
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pr_warn("%s: unrecognized huge page size 0x%lx\n",
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__func__, pagesize);
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}
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return entry;
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}
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void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
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pte_t *ptep, unsigned long sz)
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{
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int i, ncontig;
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size_t pgsize;
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ncontig = num_contig_ptes(sz, &pgsize);
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for (i = 0; i < ncontig; i++, addr += pgsize, ptep++)
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__pte_clear(mm, addr, ptep);
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}
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pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
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unsigned long addr, pte_t *ptep)
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{
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int ncontig;
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size_t pgsize;
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pte_t orig_pte = __ptep_get(ptep);
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if (!pte_cont(orig_pte))
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return __ptep_get_and_clear(mm, addr, ptep);
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ncontig = find_num_contig(mm, addr, ptep, &pgsize);
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return get_clear_contig(mm, addr, ptep, pgsize, ncontig);
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}
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/*
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* huge_ptep_set_access_flags will update access flags (dirty, accesssed)
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* and write permission.
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*
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* For a contiguous huge pte range we need to check whether or not write
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* permission has to change only on the first pte in the set. Then for
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* all the contiguous ptes we need to check whether or not there is a
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* discrepancy between dirty or young.
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*/
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static int __cont_access_flags_changed(pte_t *ptep, pte_t pte, int ncontig)
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{
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int i;
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if (pte_write(pte) != pte_write(__ptep_get(ptep)))
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return 1;
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for (i = 0; i < ncontig; i++) {
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pte_t orig_pte = __ptep_get(ptep + i);
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if (pte_dirty(pte) != pte_dirty(orig_pte))
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return 1;
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if (pte_young(pte) != pte_young(orig_pte))
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return 1;
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}
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return 0;
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}
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int huge_ptep_set_access_flags(struct vm_area_struct *vma,
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unsigned long addr, pte_t *ptep,
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pte_t pte, int dirty)
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{
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int ncontig, i;
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size_t pgsize = 0;
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unsigned long pfn = pte_pfn(pte), dpfn;
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struct mm_struct *mm = vma->vm_mm;
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pgprot_t hugeprot;
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pte_t orig_pte;
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if (!pte_cont(pte))
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return __ptep_set_access_flags(vma, addr, ptep, pte, dirty);
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ncontig = find_num_contig(mm, addr, ptep, &pgsize);
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dpfn = pgsize >> PAGE_SHIFT;
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if (!__cont_access_flags_changed(ptep, pte, ncontig))
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return 0;
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orig_pte = get_clear_contig_flush(mm, addr, ptep, pgsize, ncontig);
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/* Make sure we don't lose the dirty or young state */
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if (pte_dirty(orig_pte))
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pte = pte_mkdirty(pte);
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if (pte_young(orig_pte))
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pte = pte_mkyoung(pte);
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hugeprot = pte_pgprot(pte);
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for (i = 0; i < ncontig; i++, ptep++, addr += pgsize, pfn += dpfn)
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__set_ptes(mm, addr, ptep, pfn_pte(pfn, hugeprot), 1);
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return 1;
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}
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void huge_ptep_set_wrprotect(struct mm_struct *mm,
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unsigned long addr, pte_t *ptep)
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{
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unsigned long pfn, dpfn;
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pgprot_t hugeprot;
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int ncontig, i;
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size_t pgsize;
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pte_t pte;
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if (!pte_cont(__ptep_get(ptep))) {
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__ptep_set_wrprotect(mm, addr, ptep);
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return;
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}
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ncontig = find_num_contig(mm, addr, ptep, &pgsize);
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dpfn = pgsize >> PAGE_SHIFT;
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pte = get_clear_contig_flush(mm, addr, ptep, pgsize, ncontig);
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pte = pte_wrprotect(pte);
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hugeprot = pte_pgprot(pte);
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pfn = pte_pfn(pte);
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for (i = 0; i < ncontig; i++, ptep++, addr += pgsize, pfn += dpfn)
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__set_ptes(mm, addr, ptep, pfn_pte(pfn, hugeprot), 1);
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}
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pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
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unsigned long addr, pte_t *ptep)
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{
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struct mm_struct *mm = vma->vm_mm;
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size_t pgsize;
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int ncontig;
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if (!pte_cont(__ptep_get(ptep)))
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return ptep_clear_flush(vma, addr, ptep);
|
|
|
|
ncontig = find_num_contig(mm, addr, ptep, &pgsize);
|
|
return get_clear_contig_flush(mm, addr, ptep, pgsize, ncontig);
|
|
}
|
|
|
|
static int __init hugetlbpage_init(void)
|
|
{
|
|
if (pud_sect_supported())
|
|
hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
|
|
|
|
hugetlb_add_hstate(CONT_PMD_SHIFT - PAGE_SHIFT);
|
|
hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
|
|
hugetlb_add_hstate(CONT_PTE_SHIFT - PAGE_SHIFT);
|
|
|
|
return 0;
|
|
}
|
|
arch_initcall(hugetlbpage_init);
|
|
|
|
bool __init arch_hugetlb_valid_size(unsigned long size)
|
|
{
|
|
return __hugetlb_valid_size(size);
|
|
}
|
|
|
|
pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
|
|
{
|
|
if (alternative_has_cap_unlikely(ARM64_WORKAROUND_2645198)) {
|
|
/*
|
|
* Break-before-make (BBM) is required for all user space mappings
|
|
* when the permission changes from executable to non-executable
|
|
* in cases where cpu is affected with errata #2645198.
|
|
*/
|
|
if (pte_user_exec(__ptep_get(ptep)))
|
|
return huge_ptep_clear_flush(vma, addr, ptep);
|
|
}
|
|
return huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
|
|
}
|
|
|
|
void huge_ptep_modify_prot_commit(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep,
|
|
pte_t old_pte, pte_t pte)
|
|
{
|
|
unsigned long psize = huge_page_size(hstate_vma(vma));
|
|
|
|
set_huge_pte_at(vma->vm_mm, addr, ptep, pte, psize);
|
|
}
|