xref: /openbmc/linux/arch/s390/include/asm/hugetlb.h (revision 2cf1c348) 
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 	if (len & ~HPAGE_MASK)
32 		return -EINVAL;
33 	if (addr & ~HPAGE_MASK)
34 		return -EINVAL;
35 	return 0;
36 }
37 
38 static inline void arch_clear_hugepage_flags(struct page *page)
39 {
40 	clear_bit(PG_arch_1, &page->flags);
41 }
42 #define arch_clear_hugepage_flags arch_clear_hugepage_flags
43 
44 static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
45 				  pte_t *ptep, unsigned long sz)
46 {
47 	if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
48 		pte_val(*ptep) = _REGION3_ENTRY_EMPTY;
49 	else
50 		pte_val(*ptep) = _SEGMENT_ENTRY_EMPTY;
51 }
52 
53 static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
54 					 unsigned long address, pte_t *ptep)
55 {
56 	huge_ptep_get_and_clear(vma->vm_mm, address, ptep);
57 }
58 
59 static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
60 					     unsigned long addr, pte_t *ptep,
61 					     pte_t pte, int dirty)
62 {
63 	int changed = !pte_same(huge_ptep_get(ptep), pte);
64 	if (changed) {
65 		huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
66 		set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
67 	}
68 	return changed;
69 }
70 
71 static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
72 					   unsigned long addr, pte_t *ptep)
73 {
74 	pte_t pte = huge_ptep_get_and_clear(mm, addr, ptep);
75 	set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
76 }
77 
78 static inline pte_t mk_huge_pte(struct page *page, pgprot_t pgprot)
79 {
80 	return mk_pte(page, pgprot);
81 }
82 
83 static inline int huge_pte_none(pte_t pte)
84 {
85 	return pte_none(pte);
86 }
87 
88 static inline int huge_pte_write(pte_t pte)
89 {
90 	return pte_write(pte);
91 }
92 
93 static inline int huge_pte_dirty(pte_t pte)
94 {
95 	return pte_dirty(pte);
96 }
97 
98 static inline pte_t huge_pte_mkwrite(pte_t pte)
99 {
100 	return pte_mkwrite(pte);
101 }
102 
103 static inline pte_t huge_pte_mkdirty(pte_t pte)
104 {
105 	return pte_mkdirty(pte);
106 }
107 
108 static inline pte_t huge_pte_wrprotect(pte_t pte)
109 {
110 	return pte_wrprotect(pte);
111 }
112 
113 static inline pte_t huge_pte_modify(pte_t pte, pgprot_t newprot)
114 {
115 	return pte_modify(pte, newprot);
116 }
117 
118 static inline bool gigantic_page_runtime_supported(void)
119 {
120 	return true;
121 }
122 
123 #endif /* _ASM_S390_HUGETLB_H */
124