xref: /openbmc/linux/arch/s390/include/asm/hugetlb.h (revision 046b212a) 
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  *  IBM System z Huge TLB Page Support for Kernel.
4  *
5  *    Copyright IBM Corp. 2008
6  *    Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
7  */
8 
9 #ifndef _ASM_S390_HUGETLB_H
10 #define _ASM_S390_HUGETLB_H
11 
12 #include <linux/pgtable.h>
13 #include <asm/page.h>
14 
15 #define hugetlb_free_pgd_range			free_pgd_range
16 #define hugepages_supported()			(MACHINE_HAS_EDAT1)
17 
18 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
19 		     pte_t *ptep, pte_t pte);
20 pte_t huge_ptep_get(pte_t *ptep);
21 pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
22 			      unsigned long addr, pte_t *ptep);
23 
24 /*
25  * If the arch doesn't supply something else, assume that hugepage
26  * size aligned regions are ok without further preparation.
27  */
28 static inline int prepare_hugepage_range(struct file *file,
29 			unsigned long addr, unsigned long len)
30 {
31 	struct hstate *h = hstate_file(file);
32 
33 	if (len & ~huge_page_mask(h))
34 		return -EINVAL;
35 	if (addr & ~huge_page_mask(h))
36 		return -EINVAL;
37 	return 0;
38 }
39 
40 static inline void arch_clear_hugepage_flags(struct page *page)
41 {
42 	clear_bit(PG_arch_1, &page->flags);
43 }
44 #define arch_clear_hugepage_flags arch_clear_hugepage_flags
45 
46 static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
47 				  pte_t *ptep, unsigned long sz)
48 {
49 	if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
50 		set_pte(ptep, __pte(_REGION3_ENTRY_EMPTY));
51 	else
52 		set_pte(ptep, __pte(_SEGMENT_ENTRY_EMPTY));
53 }
54 
55 static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
56 					  unsigned long address, pte_t *ptep)
57 {
58 	return huge_ptep_get_and_clear(vma->vm_mm, address, ptep);
59 }
60 
61 static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
62 					     unsigned long addr, pte_t *ptep,
63 					     pte_t pte, int dirty)
64 {
65 	int changed = !pte_same(huge_ptep_get(ptep), pte);
66 	if (changed) {
67 		huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
68 		set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
69 	}
70 	return changed;
71 }
72 
73 static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
74 					   unsigned long addr, pte_t *ptep)
75 {
76 	pte_t pte = huge_ptep_get_and_clear(mm, addr, ptep);
77 	set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
78 }
79 
80 static inline pte_t mk_huge_pte(struct page *page, pgprot_t pgprot)
81 {
82 	return mk_pte(page, pgprot);
83 }
84 
85 static inline int huge_pte_none(pte_t pte)
86 {
87 	return pte_none(pte);
88 }
89 
90 static inline int huge_pte_none_mostly(pte_t pte)
91 {
92 	return huge_pte_none(pte);
93 }
94 
95 static inline int huge_pte_write(pte_t pte)
96 {
97 	return pte_write(pte);
98 }
99 
100 static inline int huge_pte_dirty(pte_t pte)
101 {
102 	return pte_dirty(pte);
103 }
104 
105 static inline pte_t huge_pte_mkwrite(pte_t pte)
106 {
107 	return pte_mkwrite_novma(pte);
108 }
109 
110 static inline pte_t huge_pte_mkdirty(pte_t pte)
111 {
112 	return pte_mkdirty(pte);
113 }
114 
115 static inline pte_t huge_pte_wrprotect(pte_t pte)
116 {
117 	return pte_wrprotect(pte);
118 }
119 
120 static inline pte_t huge_pte_modify(pte_t pte, pgprot_t newprot)
121 {
122 	return pte_modify(pte, newprot);
123 }
124 
125 static inline pte_t huge_pte_mkuffd_wp(pte_t pte)
126 {
127 	return pte;
128 }
129 
130 static inline pte_t huge_pte_clear_uffd_wp(pte_t pte)
131 {
132 	return pte;
133 }
134 
135 static inline int huge_pte_uffd_wp(pte_t pte)
136 {
137 	return 0;
138 }
139 
140 static inline bool gigantic_page_runtime_supported(void)
141 {
142 	return true;
143 }
144 
145 #endif /* _ASM_S390_HUGETLB_H */
146