567 lines
13 KiB
C
567 lines
13 KiB
C
// 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);
|
|
}
|
|
|
|
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
|
|
pte_t *ptep, pte_t pte, unsigned long sz)
|
|
{
|
|
size_t pgsize;
|
|
int i;
|
|
int ncontig;
|
|
unsigned long pfn, dpfn;
|
|
pgprot_t hugeprot;
|
|
|
|
ncontig = num_contig_ptes(sz, &pgsize);
|
|
|
|
if (!pte_present(pte)) {
|
|
for (i = 0; i < ncontig; i++, ptep++, addr += pgsize)
|
|
set_pte_at(mm, addr, ptep, pte);
|
|
return;
|
|
}
|
|
|
|
if (!pte_cont(pte)) {
|
|
set_pte_at(mm, addr, ptep, pte);
|
|
return;
|
|
}
|
|
|
|
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));
|
|
ptep = pte_alloc_huge(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_huge(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);
|
|
}
|
|
|
|
pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
|
|
{
|
|
if (IS_ENABLED(CONFIG_ARM64_ERRATUM_2645198) &&
|
|
cpus_have_const_cap(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(READ_ONCE(*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);
|
|
}
|