xref: /openbmc/linux/arch/s390/include/asm/hugetlb.h (revision 8795a739) 
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 <asm/page.h>
13 #include <asm/pgtable.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 static inline bool is_hugepage_only_range(struct mm_struct *mm,
25 					  unsigned long addr,
26 					  unsigned long len)
27 {
28 	return false;
29 }
30 
31 /*
32  * If the arch doesn't supply something else, assume that hugepage
33  * size aligned regions are ok without further preparation.
34  */
35 static inline int prepare_hugepage_range(struct file *file,
36 			unsigned long addr, unsigned long len)
37 {
38 	if (len & ~HPAGE_MASK)
39 		return -EINVAL;
40 	if (addr & ~HPAGE_MASK)
41 		return -EINVAL;
42 	return 0;
43 }
44 
45 static inline void arch_clear_hugepage_flags(struct page *page)
46 {
47 	clear_bit(PG_arch_1, &page->flags);
48 }
49 
50 static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
51 				  pte_t *ptep, unsigned long sz)
52 {
53 	if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
54 		pte_val(*ptep) = _REGION3_ENTRY_EMPTY;
55 	else
56 		pte_val(*ptep) = _SEGMENT_ENTRY_EMPTY;
57 }
58 
59 static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
60 					 unsigned long address, pte_t *ptep)
61 {
62 	huge_ptep_get_and_clear(vma->vm_mm, address, ptep);
63 }
64 
65 static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
66 					     unsigned long addr, pte_t *ptep,
67 					     pte_t pte, int dirty)
68 {
69 	int changed = !pte_same(huge_ptep_get(ptep), pte);
70 	if (changed) {
71 		huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
72 		set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
73 	}
74 	return changed;
75 }
76 
77 static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
78 					   unsigned long addr, pte_t *ptep)
79 {
80 	pte_t pte = huge_ptep_get_and_clear(mm, addr, ptep);
81 	set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
82 }
83 
84 static inline pte_t mk_huge_pte(struct page *page, pgprot_t pgprot)
85 {
86 	return mk_pte(page, pgprot);
87 }
88 
89 static inline int huge_pte_none(pte_t pte)
90 {
91 	return pte_none(pte);
92 }
93 
94 static inline int huge_pte_write(pte_t pte)
95 {
96 	return pte_write(pte);
97 }
98 
99 static inline int huge_pte_dirty(pte_t pte)
100 {
101 	return pte_dirty(pte);
102 }
103 
104 static inline pte_t huge_pte_mkwrite(pte_t pte)
105 {
106 	return pte_mkwrite(pte);
107 }
108 
109 static inline pte_t huge_pte_mkdirty(pte_t pte)
110 {
111 	return pte_mkdirty(pte);
112 }
113 
114 static inline pte_t huge_pte_wrprotect(pte_t pte)
115 {
116 	return pte_wrprotect(pte);
117 }
118 
119 static inline pte_t huge_pte_modify(pte_t pte, pgprot_t newprot)
120 {
121 	return pte_modify(pte, newprot);
122 }
123 
124 static inline bool gigantic_page_runtime_supported(void)
125 {
126 	return true;
127 }
128 
129 #endif /* _ASM_S390_HUGETLB_H */
130