hugetlbpage.c

 1// SPDX-License-Identifier: GPL-2.0
 2/*
 3 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
 4 */
 5
 6#include <linux/fs.h>
 7#include <linux/mm.h>
 8#include <linux/hugetlb.h>
 9#include <linux/pagemap.h>
10#include <linux/err.h>
11#include <linux/sysctl.h>
12#include <asm/mman.h>
13#include <asm/tlb.h>
14#include <asm/tlbflush.h>
15
16pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
17		      unsigned long addr, unsigned long sz)
18{
19	pgd_t *pgd;
20	p4d_t *p4d;
21	pud_t *pud;
22	pte_t *pte = NULL;
23
24	pgd = pgd_offset(mm, addr);
25	p4d = p4d_alloc(mm, pgd, addr);
26	pud = pud_alloc(mm, p4d, addr);
27	if (pud)
28		pte = (pte_t *)pmd_alloc(mm, pud, addr);
29
30	return pte;
31}
32
33pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr,
34		       unsigned long sz)
35{
36	pgd_t *pgd;
37	p4d_t *p4d;
38	pud_t *pud;
39	pmd_t *pmd = NULL;
40
41	pgd = pgd_offset(mm, addr);
42	if (pgd_present(pgdp_get(pgd))) {
43		p4d = p4d_offset(pgd, addr);
44		if (p4d_present(p4dp_get(p4d))) {
45			pud = pud_offset(p4d, addr);
46			if (pud_present(pudp_get(pud)))
47				pmd = pmd_offset(pud, addr);
48		}
49	}
50
51	return (!pmd || pmd_none(pmdp_get(pmd))) ? NULL : (pte_t *) pmd;
52}
53
54uint64_t pmd_to_entrylo(unsigned long pmd_val)
55{
56	uint64_t val;
57	/* PMD as PTE. Must be huge page */
58	if (!pmd_leaf(__pmd(pmd_val)))
59		panic("%s", __func__);
60
61	val = pmd_val ^ _PAGE_HUGE;
62	val |= ((val & _PAGE_HGLOBAL) >>
63		(_PAGE_HGLOBAL_SHIFT - _PAGE_GLOBAL_SHIFT));
64
65	return val;
66}