xref: /linux/arch/loongarch/mm/hugetlbpage.c (revision b2db6f4ace72e71fa09b8d1354f8ac9854140d74)
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 
16 pte_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 
33 pte_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 	return (pte_t *) pmd;
51 }
52 
53 uint64_t pmd_to_entrylo(unsigned long pmd_val)
54 {
55 	uint64_t val;
56 	/* PMD as PTE. Must be huge page */
57 	if (!pmd_leaf(__pmd(pmd_val)))
58 		panic("%s", __func__);
59 
60 	val = pmd_val ^ _PAGE_HUGE;
61 	val |= ((val & _PAGE_HGLOBAL) >>
62 		(_PAGE_HGLOBAL_SHIFT - _PAGE_GLOBAL_SHIFT));
63 
64 	return val;
65 }
66