1 /*
2  * MIPS Huge TLB Page Support for Kernel.
3  *
4  * This file is subject to the terms and conditions of the GNU General Public
5  * License.  See the file "COPYING" in the main directory of this archive
6  * for more details.
7  *
8  * Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com>
9  * Copyright 2005, Embedded Alley Solutions, Inc.
10  * Matt Porter <mporter@embeddedalley.com>
11  * Copyright (C) 2008, 2009 Cavium Networks, Inc.
12  */
13 
14 #include <linux/fs.h>
15 #include <linux/mm.h>
16 #include <linux/hugetlb.h>
17 #include <linux/pagemap.h>
18 #include <linux/err.h>
19 #include <linux/sysctl.h>
20 #include <asm/mman.h>
21 #include <asm/tlb.h>
22 #include <asm/tlbflush.h>
23 
huge_pte_alloc(struct mm_struct * mm,struct vm_area_struct * vma,unsigned long addr,unsigned long sz)24 pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
25 		      unsigned long addr, unsigned long sz)
26 {
27 	pgd_t *pgd;
28 	p4d_t *p4d;
29 	pud_t *pud;
30 	pte_t *pte = NULL;
31 
32 	pgd = pgd_offset(mm, addr);
33 	p4d = p4d_alloc(mm, pgd, addr);
34 	pud = pud_alloc(mm, p4d, addr);
35 	if (pud)
36 		pte = (pte_t *)pmd_alloc(mm, pud, addr);
37 
38 	return pte;
39 }
40 
huge_pte_offset(struct mm_struct * mm,unsigned long addr,unsigned long sz)41 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr,
42 		       unsigned long sz)
43 {
44 	pgd_t *pgd;
45 	p4d_t *p4d;
46 	pud_t *pud;
47 	pmd_t *pmd = NULL;
48 
49 	pgd = pgd_offset(mm, addr);
50 	if (pgd_present(*pgd)) {
51 		p4d = p4d_offset(pgd, addr);
52 		if (p4d_present(*p4d)) {
53 			pud = pud_offset(p4d, addr);
54 			if (pud_present(*pud))
55 				pmd = pmd_offset(pud, addr);
56 		}
57 	}
58 	return (pte_t *) pmd;
59 }
60 
pmd_huge(pmd_t pmd)61 int pmd_huge(pmd_t pmd)
62 {
63 	return (pmd_val(pmd) & _PAGE_HUGE) != 0;
64 }
65 
pud_huge(pud_t pud)66 int pud_huge(pud_t pud)
67 {
68 	return (pud_val(pud) & _PAGE_HUGE) != 0;
69 }
70