xref: /openbmc/linux/arch/mips/mm/hugetlbpage.c (revision e2c75e76)
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 
24 pte_t *huge_pte_alloc(struct mm_struct *mm, unsigned long addr,
25 		      unsigned long sz)
26 {
27 	pgd_t *pgd;
28 	pud_t *pud;
29 	pte_t *pte = NULL;
30 
31 	pgd = pgd_offset(mm, addr);
32 	pud = pud_alloc(mm, pgd, addr);
33 	if (pud)
34 		pte = (pte_t *)pmd_alloc(mm, pud, addr);
35 
36 	return pte;
37 }
38 
39 pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr,
40 		       unsigned long sz)
41 {
42 	pgd_t *pgd;
43 	pud_t *pud;
44 	pmd_t *pmd = NULL;
45 
46 	pgd = pgd_offset(mm, addr);
47 	if (pgd_present(*pgd)) {
48 		pud = pud_offset(pgd, addr);
49 		if (pud_present(*pud))
50 			pmd = pmd_offset(pud, addr);
51 	}
52 	return (pte_t *) pmd;
53 }
54 
55 /*
56  * This function checks for proper alignment of input addr and len parameters.
57  */
58 int is_aligned_hugepage_range(unsigned long addr, unsigned long len)
59 {
60 	if (len & ~HPAGE_MASK)
61 		return -EINVAL;
62 	if (addr & ~HPAGE_MASK)
63 		return -EINVAL;
64 	return 0;
65 }
66 
67 int pmd_huge(pmd_t pmd)
68 {
69 	return (pmd_val(pmd) & _PAGE_HUGE) != 0;
70 }
71 
72 int pud_huge(pud_t pud)
73 {
74 	return (pud_val(pud) & _PAGE_HUGE) != 0;
75 }
76