1/*
2 *  IBM System z Huge TLB Page Support for Kernel.
3 *
4 *    Copyright IBM Corp. 2008
5 *    Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
6 */
7
8#ifndef _ASM_S390_HUGETLB_H
9#define _ASM_S390_HUGETLB_H
10
11#include <asm/page.h>
12#include <asm/pgtable.h>
13
14
15#define is_hugepage_only_range(mm, addr, len)	0
16#define hugetlb_free_pgd_range			free_pgd_range
17#define hugepages_supported()			(MACHINE_HAS_HPAGE)
18
19void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
20		     pte_t *ptep, pte_t pte);
21pte_t huge_ptep_get(pte_t *ptep);
22pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
23			      unsigned long addr, pte_t *ptep);
24
25/*
26 * If the arch doesn't supply something else, assume that hugepage
27 * size aligned regions are ok without further preparation.
28 */
29static inline int prepare_hugepage_range(struct file *file,
30			unsigned long addr, unsigned long len)
31{
32	if (len & ~HPAGE_MASK)
33		return -EINVAL;
34	if (addr & ~HPAGE_MASK)
35		return -EINVAL;
36	return 0;
37}
38
39#define hugetlb_prefault_arch_hook(mm)		do { } while (0)
40#define arch_clear_hugepage_flags(page)		do { } while (0)
41
42int arch_prepare_hugepage(struct page *page);
43void arch_release_hugepage(struct page *page);
44
45static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
46				  pte_t *ptep)
47{
48	pte_val(*ptep) = _SEGMENT_ENTRY_EMPTY;
49}
50
51static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
52					 unsigned long address, pte_t *ptep)
53{
54	huge_ptep_get_and_clear(vma->vm_mm, address, ptep);
55}
56
57static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
58					     unsigned long addr, pte_t *ptep,
59					     pte_t pte, int dirty)
60{
61	int changed = !pte_same(huge_ptep_get(ptep), pte);
62	if (changed) {
63		huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
64		set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
65	}
66	return changed;
67}
68
69static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
70					   unsigned long addr, pte_t *ptep)
71{
72	pte_t pte = huge_ptep_get_and_clear(mm, addr, ptep);
73	set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
74}
75
76static inline pte_t mk_huge_pte(struct page *page, pgprot_t pgprot)
77{
78	return mk_pte(page, pgprot);
79}
80
81static inline int huge_pte_none(pte_t pte)
82{
83	return pte_none(pte);
84}
85
86static inline int huge_pte_write(pte_t pte)
87{
88	return pte_write(pte);
89}
90
91static inline int huge_pte_dirty(pte_t pte)
92{
93	return pte_dirty(pte);
94}
95
96static inline pte_t huge_pte_mkwrite(pte_t pte)
97{
98	return pte_mkwrite(pte);
99}
100
101static inline pte_t huge_pte_mkdirty(pte_t pte)
102{
103	return pte_mkdirty(pte);
104}
105
106static inline pte_t huge_pte_wrprotect(pte_t pte)
107{
108	return pte_wrprotect(pte);
109}
110
111static inline pte_t huge_pte_modify(pte_t pte, pgprot_t newprot)
112{
113	return pte_modify(pte, newprot);
114}
115
116#endif /* _ASM_S390_HUGETLB_H */
117