https://github.com/torvalds/linux
Tip revision: c3f38fa61af77b49866b006939479069cd451173 authored by Linus Torvalds on 02 June 2024, 22:44:56 UTC
Linux 6.10-rc2
Linux 6.10-rc2
Tip revision: c3f38fa
hugetlbpage.c
// SPDX-License-Identifier: GPL-2.0
#include <linux/hugetlb.h>
#include <linux/err.h>
#ifdef CONFIG_RISCV_ISA_SVNAPOT
pte_t huge_ptep_get(pte_t *ptep)
{
unsigned long pte_num;
int i;
pte_t orig_pte = ptep_get(ptep);
if (!pte_present(orig_pte) || !pte_napot(orig_pte))
return orig_pte;
pte_num = napot_pte_num(napot_cont_order(orig_pte));
for (i = 0; i < pte_num; 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;
}
pte_t *huge_pte_alloc(struct mm_struct *mm,
struct vm_area_struct *vma,
unsigned long addr,
unsigned long sz)
{
unsigned long order;
pte_t *pte = NULL;
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pgd = pgd_offset(mm, addr);
p4d = p4d_alloc(mm, pgd, addr);
if (!p4d)
return NULL;
pud = pud_alloc(mm, p4d, addr);
if (!pud)
return NULL;
if (sz == PUD_SIZE) {
pte = (pte_t *)pud;
goto out;
}
if (sz == PMD_SIZE) {
if (want_pmd_share(vma, addr) && pud_none(pudp_get(pud)))
pte = huge_pmd_share(mm, vma, addr, pud);
else
pte = (pte_t *)pmd_alloc(mm, pud, addr);
goto out;
}
pmd = pmd_alloc(mm, pud, addr);
if (!pmd)
return NULL;
for_each_napot_order(order) {
if (napot_cont_size(order) == sz) {
pte = pte_alloc_huge(mm, pmd, addr & napot_cont_mask(order));
break;
}
}
out:
if (pte) {
pte_t pteval = ptep_get_lockless(pte);
WARN_ON_ONCE(pte_present(pteval) && !pte_huge(pteval));
}
return pte;
}
pte_t *huge_pte_offset(struct mm_struct *mm,
unsigned long addr,
unsigned long sz)
{
unsigned long order;
pte_t *pte = NULL;
pgd_t *pgd;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pgd = pgd_offset(mm, addr);
if (!pgd_present(pgdp_get(pgd)))
return NULL;
p4d = p4d_offset(pgd, addr);
if (!p4d_present(p4dp_get(p4d)))
return NULL;
pud = pud_offset(p4d, addr);
if (sz == PUD_SIZE)
/* must be pud huge, non-present or none */
return (pte_t *)pud;
if (!pud_present(pudp_get(pud)))
return NULL;
pmd = pmd_offset(pud, addr);
if (sz == PMD_SIZE)
/* must be pmd huge, non-present or none */
return (pte_t *)pmd;
if (!pmd_present(pmdp_get(pmd)))
return NULL;
for_each_napot_order(order) {
if (napot_cont_size(order) == sz) {
pte = pte_offset_huge(pmd, addr & napot_cont_mask(order));
break;
}
}
return pte;
}
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 P4D_SIZE - PUD_SIZE;
#endif
case PMD_SIZE:
return PUD_SIZE - PMD_SIZE;
case napot_cont_size(NAPOT_CONT64KB_ORDER):
return PMD_SIZE - napot_cont_size(NAPOT_CONT64KB_ORDER);
default:
break;
}
return 0UL;
}
static pte_t get_clear_contig(struct mm_struct *mm,
unsigned long addr,
pte_t *ptep,
unsigned long pte_num)
{
pte_t orig_pte = ptep_get(ptep);
unsigned long i;
for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++) {
pte_t pte = ptep_get_and_clear(mm, addr, ptep);
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 pte_num)
{
pte_t orig_pte = get_clear_contig(mm, addr, ptep, pte_num);
struct vm_area_struct vma = TLB_FLUSH_VMA(mm, 0);
bool valid = !pte_none(orig_pte);
if (valid)
flush_tlb_range(&vma, addr, addr + (PAGE_SIZE * pte_num));
return orig_pte;
}
pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags)
{
unsigned long order;
for_each_napot_order(order) {
if (shift == napot_cont_shift(order)) {
entry = pte_mknapot(entry, order);
break;
}
}
if (order == NAPOT_ORDER_MAX)
entry = pte_mkhuge(entry);
return entry;
}
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_get_and_clear(mm, addr, ptep);
flush_tlb_range(&vma, saddr, addr);
}
/*
* When dealing with NAPOT mappings, the privileged specification indicates that
* "if an update needs to be made, the OS generally should first mark all of the
* PTEs invalid, then issue SFENCE.VMA instruction(s) covering all 4 KiB regions
* within the range, [...] then update the PTE(s), as described in Section
* 4.2.1.". That's the equivalent of the Break-Before-Make approach used by
* arm64.
*/
void set_huge_pte_at(struct mm_struct *mm,
unsigned long addr,
pte_t *ptep,
pte_t pte,
unsigned long sz)
{
unsigned long hugepage_shift, pgsize;
int i, pte_num;
if (sz >= PGDIR_SIZE)
hugepage_shift = PGDIR_SHIFT;
else if (sz >= P4D_SIZE)
hugepage_shift = P4D_SHIFT;
else if (sz >= PUD_SIZE)
hugepage_shift = PUD_SHIFT;
else if (sz >= PMD_SIZE)
hugepage_shift = PMD_SHIFT;
else
hugepage_shift = PAGE_SHIFT;
pte_num = sz >> hugepage_shift;
pgsize = 1 << hugepage_shift;
if (!pte_present(pte)) {
for (i = 0; i < pte_num; i++, ptep++, addr += pgsize)
set_ptes(mm, addr, ptep, pte, 1);
return;
}
if (!pte_napot(pte)) {
set_ptes(mm, addr, ptep, pte, 1);
return;
}
clear_flush(mm, addr, ptep, pgsize, pte_num);
for (i = 0; i < pte_num; i++, ptep++, addr += pgsize)
set_pte_at(mm, addr, ptep, pte);
}
int huge_ptep_set_access_flags(struct vm_area_struct *vma,
unsigned long addr,
pte_t *ptep,
pte_t pte,
int dirty)
{
struct mm_struct *mm = vma->vm_mm;
unsigned long order;
pte_t orig_pte;
int i, pte_num;
if (!pte_napot(pte))
return ptep_set_access_flags(vma, addr, ptep, pte, dirty);
order = napot_cont_order(pte);
pte_num = napot_pte_num(order);
ptep = huge_pte_offset(mm, addr, napot_cont_size(order));
orig_pte = get_clear_contig_flush(mm, addr, ptep, pte_num);
if (pte_dirty(orig_pte))
pte = pte_mkdirty(pte);
if (pte_young(orig_pte))
pte = pte_mkyoung(pte);
for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++)
set_pte_at(mm, addr, ptep, pte);
return true;
}
pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
unsigned long addr,
pte_t *ptep)
{
pte_t orig_pte = ptep_get(ptep);
int pte_num;
if (!pte_napot(orig_pte))
return ptep_get_and_clear(mm, addr, ptep);
pte_num = napot_pte_num(napot_cont_order(orig_pte));
return get_clear_contig(mm, addr, ptep, pte_num);
}
void huge_ptep_set_wrprotect(struct mm_struct *mm,
unsigned long addr,
pte_t *ptep)
{
pte_t pte = ptep_get(ptep);
unsigned long order;
pte_t orig_pte;
int i, pte_num;
if (!pte_napot(pte)) {
ptep_set_wrprotect(mm, addr, ptep);
return;
}
order = napot_cont_order(pte);
pte_num = napot_pte_num(order);
ptep = huge_pte_offset(mm, addr, napot_cont_size(order));
orig_pte = get_clear_contig_flush(mm, addr, ptep, pte_num);
orig_pte = pte_wrprotect(orig_pte);
for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++)
set_pte_at(mm, addr, ptep, orig_pte);
}
pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
unsigned long addr,
pte_t *ptep)
{
pte_t pte = ptep_get(ptep);
int pte_num;
if (!pte_napot(pte))
return ptep_clear_flush(vma, addr, ptep);
pte_num = napot_pte_num(napot_cont_order(pte));
return get_clear_contig_flush(vma->vm_mm, addr, ptep, pte_num);
}
void huge_pte_clear(struct mm_struct *mm,
unsigned long addr,
pte_t *ptep,
unsigned long sz)
{
pte_t pte = ptep_get(ptep);
int i, pte_num;
if (!pte_napot(pte)) {
pte_clear(mm, addr, ptep);
return;
}
pte_num = napot_pte_num(napot_cont_order(pte));
for (i = 0; i < pte_num; i++, addr += PAGE_SIZE, ptep++)
pte_clear(mm, addr, ptep);
}
static bool is_napot_size(unsigned long size)
{
unsigned long order;
if (!has_svnapot())
return false;
for_each_napot_order(order) {
if (size == napot_cont_size(order))
return true;
}
return false;
}
static __init int napot_hugetlbpages_init(void)
{
if (has_svnapot()) {
unsigned long order;
for_each_napot_order(order)
hugetlb_add_hstate(order);
}
return 0;
}
arch_initcall(napot_hugetlbpages_init);
#else
static bool is_napot_size(unsigned long size)
{
return false;
}
#endif /*CONFIG_RISCV_ISA_SVNAPOT*/
static bool __hugetlb_valid_size(unsigned long size)
{
if (size == HPAGE_SIZE)
return true;
else if (IS_ENABLED(CONFIG_64BIT) && size == PUD_SIZE)
return true;
else if (is_napot_size(size))
return true;
else
return false;
}
bool __init arch_hugetlb_valid_size(unsigned long size)
{
return __hugetlb_valid_size(size);
}
#ifdef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
bool arch_hugetlb_migration_supported(struct hstate *h)
{
return __hugetlb_valid_size(huge_page_size(h));
}
#endif
#ifdef CONFIG_CONTIG_ALLOC
static __init int gigantic_pages_init(void)
{
/* With CONTIG_ALLOC, we can allocate gigantic pages at runtime */
if (IS_ENABLED(CONFIG_64BIT))
hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
return 0;
}
arch_initcall(gigantic_pages_init);
#endif