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-rw-r--r--arch/arm64/mm/hugetlbpage.c561
1 files changed, 561 insertions, 0 deletions
diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
new file mode 100644
index 000000000..134dcf6bc
--- /dev/null
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -0,0 +1,561 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * arch/arm64/mm/hugetlbpage.c
+ *
+ * Copyright (C) 2013 Linaro Ltd.
+ *
+ * Based on arch/x86/mm/hugetlbpage.c.
+ */
+
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/pagemap.h>
+#include <linux/err.h>
+#include <linux/sysctl.h>
+#include <asm/mman.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+
+/*
+ * HugeTLB Support Matrix
+ *
+ * ---------------------------------------------------
+ * | Page Size | CONT PTE | PMD | CONT PMD | PUD |
+ * ---------------------------------------------------
+ * | 4K | 64K | 2M | 32M | 1G |
+ * | 16K | 2M | 32M | 1G | |
+ * | 64K | 2M | 512M | 16G | |
+ * ---------------------------------------------------
+ */
+
+/*
+ * Reserve CMA areas for the largest supported gigantic
+ * huge page when requested. Any other smaller gigantic
+ * huge pages could still be served from those areas.
+ */
+#ifdef CONFIG_CMA
+void __init arm64_hugetlb_cma_reserve(void)
+{
+ int order;
+
+ if (pud_sect_supported())
+ order = PUD_SHIFT - PAGE_SHIFT;
+ else
+ order = CONT_PMD_SHIFT - PAGE_SHIFT;
+
+ /*
+ * HugeTLB CMA reservation is required for gigantic
+ * huge pages which could not be allocated via the
+ * page allocator. Just warn if there is any change
+ * breaking this assumption.
+ */
+ WARN_ON(order <= MAX_ORDER);
+ hugetlb_cma_reserve(order);
+}
+#endif /* CONFIG_CMA */
+
+static bool __hugetlb_valid_size(unsigned long size)
+{
+ switch (size) {
+#ifndef __PAGETABLE_PMD_FOLDED
+ case PUD_SIZE:
+ return pud_sect_supported();
+#endif
+ case CONT_PMD_SIZE:
+ case PMD_SIZE:
+ case CONT_PTE_SIZE:
+ return true;
+ }
+
+ return false;
+}
+
+#ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
+bool arch_hugetlb_migration_supported(struct hstate *h)
+{
+ size_t pagesize = huge_page_size(h);
+
+ if (!__hugetlb_valid_size(pagesize)) {
+ pr_warn("%s: unrecognized huge page size 0x%lx\n",
+ __func__, pagesize);
+ return false;
+ }
+ return true;
+}
+#endif
+
+int pmd_huge(pmd_t pmd)
+{
+ return pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT);
+}
+
+int pud_huge(pud_t pud)
+{
+#ifndef __PAGETABLE_PMD_FOLDED
+ return pud_val(pud) && !(pud_val(pud) & PUD_TABLE_BIT);
+#else
+ return 0;
+#endif
+}
+
+static int find_num_contig(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, size_t *pgsize)
+{
+ pgd_t *pgdp = pgd_offset(mm, addr);
+ p4d_t *p4dp;
+ pud_t *pudp;
+ pmd_t *pmdp;
+
+ *pgsize = PAGE_SIZE;
+ p4dp = p4d_offset(pgdp, addr);
+ pudp = pud_offset(p4dp, addr);
+ pmdp = pmd_offset(pudp, addr);
+ if ((pte_t *)pmdp == ptep) {
+ *pgsize = PMD_SIZE;
+ return CONT_PMDS;
+ }
+ return CONT_PTES;
+}
+
+static inline int num_contig_ptes(unsigned long size, size_t *pgsize)
+{
+ int contig_ptes = 0;
+
+ *pgsize = size;
+
+ switch (size) {
+#ifndef __PAGETABLE_PMD_FOLDED
+ case PUD_SIZE:
+ if (pud_sect_supported())
+ contig_ptes = 1;
+ break;
+#endif
+ case PMD_SIZE:
+ contig_ptes = 1;
+ break;
+ case CONT_PMD_SIZE:
+ *pgsize = PMD_SIZE;
+ contig_ptes = CONT_PMDS;
+ break;
+ case CONT_PTE_SIZE:
+ *pgsize = PAGE_SIZE;
+ contig_ptes = CONT_PTES;
+ break;
+ }
+
+ return contig_ptes;
+}
+
+pte_t huge_ptep_get(pte_t *ptep)
+{
+ int ncontig, i;
+ size_t pgsize;
+ pte_t orig_pte = ptep_get(ptep);
+
+ if (!pte_present(orig_pte) || !pte_cont(orig_pte))
+ return orig_pte;
+
+ ncontig = num_contig_ptes(page_size(pte_page(orig_pte)), &pgsize);
+ for (i = 0; i < ncontig; i++, ptep++) {
+ pte_t pte = ptep_get(ptep);
+
+ if (pte_dirty(pte))
+ orig_pte = pte_mkdirty(orig_pte);
+
+ if (pte_young(pte))
+ orig_pte = pte_mkyoung(orig_pte);
+ }
+ return orig_pte;
+}
+
+/*
+ * Changing some bits of contiguous entries requires us to follow a
+ * Break-Before-Make approach, breaking the whole contiguous set
+ * before we can change any entries. See ARM DDI 0487A.k_iss10775,
+ * "Misprogramming of the Contiguous bit", page D4-1762.
+ *
+ * This helper performs the break step.
+ */
+static pte_t get_clear_contig(struct mm_struct *mm,
+ unsigned long addr,
+ pte_t *ptep,
+ unsigned long pgsize,
+ unsigned long ncontig)
+{
+ pte_t orig_pte = ptep_get(ptep);
+ unsigned long i;
+
+ for (i = 0; i < ncontig; i++, addr += pgsize, ptep++) {
+ pte_t pte = ptep_get_and_clear(mm, addr, ptep);
+
+ /*
+ * If HW_AFDBM is enabled, then the HW could turn on
+ * the dirty or accessed bit for any page in the set,
+ * so check them all.
+ */
+ if (pte_dirty(pte))
+ orig_pte = pte_mkdirty(orig_pte);
+
+ if (pte_young(pte))
+ orig_pte = pte_mkyoung(orig_pte);
+ }
+ return orig_pte;
+}
+
+static pte_t get_clear_contig_flush(struct mm_struct *mm,
+ unsigned long addr,
+ pte_t *ptep,
+ unsigned long pgsize,
+ unsigned long ncontig)
+{
+ pte_t orig_pte = get_clear_contig(mm, addr, ptep, pgsize, ncontig);
+ struct vm_area_struct vma = TLB_FLUSH_VMA(mm, 0);
+
+ flush_tlb_range(&vma, addr, addr + (pgsize * ncontig));
+ return orig_pte;
+}
+
+/*
+ * Changing some bits of contiguous entries requires us to follow a
+ * Break-Before-Make approach, breaking the whole contiguous set
+ * before we can change any entries. See ARM DDI 0487A.k_iss10775,
+ * "Misprogramming of the Contiguous bit", page D4-1762.
+ *
+ * This helper performs the break step for use cases where the
+ * original pte is not needed.
+ */
+static void clear_flush(struct mm_struct *mm,
+ unsigned long addr,
+ pte_t *ptep,
+ unsigned long pgsize,
+ unsigned long ncontig)
+{
+ struct vm_area_struct vma = TLB_FLUSH_VMA(mm, 0);
+ unsigned long i, saddr = addr;
+
+ for (i = 0; i < ncontig; i++, addr += pgsize, ptep++)
+ ptep_clear(mm, addr, ptep);
+
+ flush_tlb_range(&vma, saddr, addr);
+}
+
+static inline struct folio *hugetlb_swap_entry_to_folio(swp_entry_t entry)
+{
+ VM_BUG_ON(!is_migration_entry(entry) && !is_hwpoison_entry(entry));
+
+ return page_folio(pfn_to_page(swp_offset_pfn(entry)));
+}
+
+void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pte)
+{
+ size_t pgsize;
+ int i;
+ int ncontig;
+ unsigned long pfn, dpfn;
+ pgprot_t hugeprot;
+
+ if (!pte_present(pte)) {
+ struct folio *folio;
+
+ folio = hugetlb_swap_entry_to_folio(pte_to_swp_entry(pte));
+ ncontig = num_contig_ptes(folio_size(folio), &pgsize);
+
+ for (i = 0; i < ncontig; i++, ptep++)
+ set_pte_at(mm, addr, ptep, pte);
+ return;
+ }
+
+ if (!pte_cont(pte)) {
+ set_pte_at(mm, addr, ptep, pte);
+ return;
+ }
+
+ ncontig = find_num_contig(mm, addr, ptep, &pgsize);
+ pfn = pte_pfn(pte);
+ dpfn = pgsize >> PAGE_SHIFT;
+ hugeprot = pte_pgprot(pte);
+
+ clear_flush(mm, addr, ptep, pgsize, ncontig);
+
+ for (i = 0; i < ncontig; i++, ptep++, addr += pgsize, pfn += dpfn)
+ set_pte_at(mm, addr, ptep, pfn_pte(pfn, hugeprot));
+}
+
+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;
+ pte_t *ptep = NULL;
+
+ pgdp = pgd_offset(mm, addr);
+ p4dp = p4d_offset(pgdp, addr);
+ pudp = pud_alloc(mm, p4dp, addr);
+ if (!pudp)
+ return NULL;
+
+ if (sz == PUD_SIZE) {
+ ptep = (pte_t *)pudp;
+ } else if (sz == (CONT_PTE_SIZE)) {
+ pmdp = pmd_alloc(mm, pudp, addr);
+ if (!pmdp)
+ return NULL;
+
+ WARN_ON(addr & (sz - 1));
+ /*
+ * Note that if this code were ever ported to the
+ * 32-bit arm platform then it will cause trouble in
+ * the case where CONFIG_HIGHPTE is set, since there
+ * will be no pte_unmap() to correspond with this
+ * pte_alloc_map().
+ */
+ ptep = pte_alloc_map(mm, pmdp, addr);
+ } else if (sz == PMD_SIZE) {
+ if (want_pmd_share(vma, addr) && pud_none(READ_ONCE(*pudp)))
+ ptep = huge_pmd_share(mm, vma, addr, pudp);
+ else
+ ptep = (pte_t *)pmd_alloc(mm, pudp, addr);
+ } else if (sz == (CONT_PMD_SIZE)) {
+ pmdp = pmd_alloc(mm, pudp, addr);
+ WARN_ON(addr & (sz - 1));
+ return (pte_t *)pmdp;
+ }
+
+ return ptep;
+}
+
+pte_t *huge_pte_offset(struct mm_struct *mm,
+ unsigned long addr, unsigned long sz)
+{
+ pgd_t *pgdp;
+ p4d_t *p4dp;
+ pud_t *pudp, pud;
+ pmd_t *pmdp, pmd;
+
+ pgdp = pgd_offset(mm, addr);
+ if (!pgd_present(READ_ONCE(*pgdp)))
+ return NULL;
+
+ p4dp = p4d_offset(pgdp, addr);
+ if (!p4d_present(READ_ONCE(*p4dp)))
+ return NULL;
+
+ pudp = pud_offset(p4dp, addr);
+ pud = READ_ONCE(*pudp);
+ if (sz != PUD_SIZE && pud_none(pud))
+ return NULL;
+ /* hugepage or swap? */
+ if (pud_huge(pud) || !pud_present(pud))
+ return (pte_t *)pudp;
+ /* table; check the next level */
+
+ if (sz == CONT_PMD_SIZE)
+ addr &= CONT_PMD_MASK;
+
+ pmdp = pmd_offset(pudp, addr);
+ pmd = READ_ONCE(*pmdp);
+ if (!(sz == PMD_SIZE || sz == CONT_PMD_SIZE) &&
+ pmd_none(pmd))
+ return NULL;
+ if (pmd_huge(pmd) || !pmd_present(pmd))
+ return (pte_t *)pmdp;
+
+ if (sz == CONT_PTE_SIZE)
+ return pte_offset_kernel(pmdp, (addr & CONT_PTE_MASK));
+
+ return NULL;
+}
+
+unsigned long hugetlb_mask_last_page(struct hstate *h)
+{
+ unsigned long hp_size = huge_page_size(h);
+
+ switch (hp_size) {
+#ifndef __PAGETABLE_PMD_FOLDED
+ case PUD_SIZE:
+ return PGDIR_SIZE - PUD_SIZE;
+#endif
+ case CONT_PMD_SIZE:
+ return PUD_SIZE - CONT_PMD_SIZE;
+ case PMD_SIZE:
+ return PUD_SIZE - PMD_SIZE;
+ case CONT_PTE_SIZE:
+ return PMD_SIZE - CONT_PTE_SIZE;
+ default:
+ break;
+ }
+
+ return 0UL;
+}
+
+pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags)
+{
+ size_t pagesize = 1UL << shift;
+
+ entry = pte_mkhuge(entry);
+ if (pagesize == CONT_PTE_SIZE) {
+ entry = pte_mkcont(entry);
+ } else if (pagesize == CONT_PMD_SIZE) {
+ entry = pmd_pte(pmd_mkcont(pte_pmd(entry)));
+ } else if (pagesize != PUD_SIZE && pagesize != PMD_SIZE) {
+ pr_warn("%s: unrecognized huge page size 0x%lx\n",
+ __func__, pagesize);
+ }
+ return entry;
+}
+
+void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, unsigned long sz)
+{
+ int i, ncontig;
+ size_t pgsize;
+
+ ncontig = num_contig_ptes(sz, &pgsize);
+
+ for (i = 0; i < ncontig; i++, addr += pgsize, ptep++)
+ pte_clear(mm, addr, ptep);
+}
+
+pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep)
+{
+ int ncontig;
+ size_t pgsize;
+ pte_t orig_pte = ptep_get(ptep);
+
+ if (!pte_cont(orig_pte))
+ return ptep_get_and_clear(mm, addr, ptep);
+
+ ncontig = find_num_contig(mm, addr, ptep, &pgsize);
+
+ return get_clear_contig(mm, addr, ptep, pgsize, ncontig);
+}
+
+/*
+ * huge_ptep_set_access_flags will update access flags (dirty, accesssed)
+ * and write permission.
+ *
+ * For a contiguous huge pte range we need to check whether or not write
+ * permission has to change only on the first pte in the set. Then for
+ * all the contiguous ptes we need to check whether or not there is a
+ * discrepancy between dirty or young.
+ */
+static int __cont_access_flags_changed(pte_t *ptep, pte_t pte, int ncontig)
+{
+ int i;
+
+ if (pte_write(pte) != pte_write(ptep_get(ptep)))
+ return 1;
+
+ for (i = 0; i < ncontig; i++) {
+ pte_t orig_pte = ptep_get(ptep + i);
+
+ if (pte_dirty(pte) != pte_dirty(orig_pte))
+ return 1;
+
+ if (pte_young(pte) != pte_young(orig_pte))
+ return 1;
+ }
+
+ return 0;
+}
+
+int huge_ptep_set_access_flags(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep,
+ pte_t pte, int dirty)
+{
+ int ncontig, i;
+ size_t pgsize = 0;
+ unsigned long pfn = pte_pfn(pte), dpfn;
+ struct mm_struct *mm = vma->vm_mm;
+ pgprot_t hugeprot;
+ pte_t orig_pte;
+
+ if (!pte_cont(pte))
+ return ptep_set_access_flags(vma, addr, ptep, pte, dirty);
+
+ ncontig = find_num_contig(mm, addr, ptep, &pgsize);
+ dpfn = pgsize >> PAGE_SHIFT;
+
+ if (!__cont_access_flags_changed(ptep, pte, ncontig))
+ return 0;
+
+ orig_pte = get_clear_contig_flush(mm, addr, ptep, pgsize, ncontig);
+
+ /* Make sure we don't lose the dirty or young state */
+ if (pte_dirty(orig_pte))
+ pte = pte_mkdirty(pte);
+
+ if (pte_young(orig_pte))
+ pte = pte_mkyoung(pte);
+
+ hugeprot = pte_pgprot(pte);
+ for (i = 0; i < ncontig; i++, ptep++, addr += pgsize, pfn += dpfn)
+ set_pte_at(mm, addr, ptep, pfn_pte(pfn, hugeprot));
+
+ return 1;
+}
+
+void huge_ptep_set_wrprotect(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep)
+{
+ unsigned long pfn, dpfn;
+ pgprot_t hugeprot;
+ int ncontig, i;
+ size_t pgsize;
+ pte_t pte;
+
+ if (!pte_cont(READ_ONCE(*ptep))) {
+ ptep_set_wrprotect(mm, addr, ptep);
+ return;
+ }
+
+ ncontig = find_num_contig(mm, addr, ptep, &pgsize);
+ dpfn = pgsize >> PAGE_SHIFT;
+
+ pte = get_clear_contig_flush(mm, addr, ptep, pgsize, ncontig);
+ pte = pte_wrprotect(pte);
+
+ hugeprot = pte_pgprot(pte);
+ pfn = pte_pfn(pte);
+
+ for (i = 0; i < ncontig; i++, ptep++, addr += pgsize, pfn += dpfn)
+ set_pte_at(mm, addr, ptep, pfn_pte(pfn, hugeprot));
+}
+
+pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *ptep)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ size_t pgsize;
+ int ncontig;
+
+ if (!pte_cont(READ_ONCE(*ptep)))
+ 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);
+}