Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 463 insertions, 0 deletions

diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
new file mode 100644
index 000000000..1d7656761
--- /dev/null
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -0,0 +1,463 @@
+/*
+ * arch/arm64/mm/hugetlbpage.c
+ *
+ * Copyright (C) 2013 Linaro Ltd.
+ *
+ * Based on arch/x86/mm/hugetlbpage.c.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#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>
+#include <asm/pgalloc.h>
+
+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
+}
+
+/*
+ * Select all bits except the pfn
+ */
+static inline pgprot_t pte_pgprot(pte_t pte)
+{
+	unsigned long pfn = pte_pfn(pte);
+
+	return __pgprot(pte_val(pfn_pte(pfn, __pgprot(0))) ^ pte_val(pte));
+}
+
+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);
+	pud_t *pudp;
+	pmd_t *pmdp;
+
+	*pgsize = PAGE_SIZE;
+	pudp = pud_offset(pgdp, 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) {
+#ifdef CONFIG_ARM64_4K_PAGES
+	case PUD_SIZE:
+#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;
+}
+
+/*
+ * 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_flush(struct mm_struct *mm,
+			     unsigned long addr,
+			     pte_t *ptep,
+			     unsigned long pgsize,
+			     unsigned long ncontig)
+{
+	pte_t orig_pte = huge_ptep_get(ptep);
+	bool valid = pte_valid(orig_pte);
+	unsigned long i, saddr = addr;
+
+	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);
+	}
+
+	if (valid) {
+		struct vm_area_struct vma = TLB_FLUSH_VMA(mm, 0);
+		flush_tlb_range(&vma, saddr, addr);
+	}
+	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++)
+		pte_clear(mm, addr, ptep);
+
+	flush_tlb_range(&vma, saddr, addr);
+}
+
+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;
+
+	/*
+	 * Code needs to be expanded to handle huge swap and migration
+	 * entries. Needed for HUGETLB and MEMORY_FAILURE.
+	 */
+	WARN_ON(!pte_present(pte));
+
+	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));
+}
+
+void set_huge_swap_pte_at(struct mm_struct *mm, unsigned long addr,
+			  pte_t *ptep, pte_t pte, unsigned long sz)
+{
+	int i, ncontig;
+	size_t pgsize;
+
+	ncontig = num_contig_ptes(sz, &pgsize);
+
+	for (i = 0; i < ncontig; i++, ptep++)
+		set_pte(ptep, pte);
+}
+
+pte_t *huge_pte_alloc(struct mm_struct *mm,
+		      unsigned long addr, unsigned long sz)
+{
+	pgd_t *pgdp;
+	pud_t *pudp;
+	pmd_t *pmdp;
+	pte_t *ptep = NULL;
+
+	pgdp = pgd_offset(mm, addr);
+	pudp = pud_alloc(mm, pgdp, addr);
+	if (!pudp)
+		return NULL;
+
+	if (sz == PUD_SIZE) {
+		ptep = (pte_t *)pudp;
+	} else if (sz == (PAGE_SIZE * CONT_PTES)) {
+		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 (IS_ENABLED(CONFIG_ARCH_WANT_HUGE_PMD_SHARE) &&
+		    pud_none(READ_ONCE(*pudp)))
+			ptep = huge_pmd_share(mm, addr, pudp);
+		else
+			ptep = (pte_t *)pmd_alloc(mm, pudp, addr);
+	} else if (sz == (PMD_SIZE * CONT_PMDS)) {
+		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;
+	pud_t *pudp, pud;
+	pmd_t *pmdp, pmd;
+
+	pgdp = pgd_offset(mm, addr);
+	if (!pgd_present(READ_ONCE(*pgdp)))
+		return NULL;
+
+	pudp = pud_offset(pgdp, 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;
+}
+
+pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
+			 struct page *page, int writable)
+{
+	size_t pagesize = huge_page_size(hstate_vma(vma));
+
+	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 = huge_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_flush(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(huge_ptep_get(ptep)))
+		return 1;
+
+	for (i = 0; i < ncontig; i++) {
+		pte_t orig_pte = huge_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;
+	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(vma->vm_mm, addr, ptep, &pgsize);
+	dpfn = pgsize >> PAGE_SHIFT;
+
+	if (!__cont_access_flags_changed(ptep, pte, ncontig))
+		return 0;
+
+	orig_pte = get_clear_flush(vma->vm_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(vma->vm_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_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));
+}
+
+void huge_ptep_clear_flush(struct vm_area_struct *vma,
+			   unsigned long addr, pte_t *ptep)
+{
+	size_t pgsize;
+	int ncontig;
+
+	if (!pte_cont(READ_ONCE(*ptep))) {
+		ptep_clear_flush(vma, addr, ptep);
+		return;
+	}
+
+	ncontig = find_num_contig(vma->vm_mm, addr, ptep, &pgsize);
+	clear_flush(vma->vm_mm, addr, ptep, pgsize, ncontig);
+}
+
+static __init int setup_hugepagesz(char *opt)
+{
+	unsigned long ps = memparse(opt, &opt);
+
+	switch (ps) {
+#ifdef CONFIG_ARM64_4K_PAGES
+	case PUD_SIZE:
+#endif
+	case PMD_SIZE * CONT_PMDS:
+	case PMD_SIZE:
+	case PAGE_SIZE * CONT_PTES:
+		hugetlb_add_hstate(ilog2(ps) - PAGE_SHIFT);
+		return 1;
+	}
+
+	hugetlb_bad_size();
+	pr_err("hugepagesz: Unsupported page size %lu K\n", ps >> 10);
+	return 0;
+}
+__setup("hugepagesz=", setup_hugepagesz);
+
+#ifdef CONFIG_ARM64_64K_PAGES
+static __init int add_default_hugepagesz(void)
+{
+	if (size_to_hstate(CONT_PTES * PAGE_SIZE) == NULL)
+		hugetlb_add_hstate(CONT_PTE_SHIFT);
+	return 0;
+}
+arch_initcall(add_default_hugepagesz);
+#endif