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/cpufeature.h>
13 #include <linux/pgtable.h>
14 #include <linux/swap.h>
15 #include <linux/swapops.h>
16 #include <asm/page.h>
17 
18 #define hugepages_supported()	cpu_has_edat1()
19 
20 #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
21 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
22 		     pte_t *ptep, pte_t pte, unsigned long sz);
23 void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
24 		       pte_t *ptep, pte_t pte);
25 
26 #define __HAVE_ARCH_HUGE_PTEP_GET
27 pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
28 
29 pte_t __huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
30 				pte_t *ptep);
31 
32 #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
33 static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
34 					    unsigned long addr, pte_t *ptep,
35 					    unsigned long sz)
36 {
37 	return __huge_ptep_get_and_clear(mm, addr, ptep);
38 }
39 
40 static inline void arch_clear_hugetlb_flags(struct folio *folio)
41 {
42 	clear_bit(PG_arch_1, &folio->flags);
43 }
44 #define arch_clear_hugetlb_flags arch_clear_hugetlb_flags
45 
46 #define __HAVE_ARCH_HUGE_PTE_CLEAR
47 static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
48 				  pte_t *ptep, unsigned long sz)
49 {
50 	if ((pte_val(*ptep) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3)
51 		set_pte(ptep, __pte(_REGION3_ENTRY_EMPTY));
52 	else
53 		set_pte(ptep, __pte(_SEGMENT_ENTRY_EMPTY));
54 }
55 
56 #define __HAVE_ARCH_HUGE_PTEP_CLEAR_FLUSH
57 static inline pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
58 					  unsigned long address, pte_t *ptep)
59 {
60 	return __huge_ptep_get_and_clear(vma->vm_mm, address, ptep);
61 }
62 
63 #define  __HAVE_ARCH_HUGE_PTEP_SET_ACCESS_FLAGS
64 static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
65 					     unsigned long addr, pte_t *ptep,
66 					     pte_t pte, int dirty)
67 {
68 	int changed = !pte_same(huge_ptep_get(vma->vm_mm, addr, ptep), pte);
69 
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 #define __HAVE_ARCH_HUGE_PTEP_SET_WRPROTECT
78 static inline void huge_ptep_set_wrprotect(struct mm_struct *mm,
79 					   unsigned long addr, pte_t *ptep)
80 {
81 	pte_t pte = __huge_ptep_get_and_clear(mm, addr, ptep);
82 
83 	__set_huge_pte_at(mm, addr, ptep, pte_wrprotect(pte));
84 }
85 
86 #define __HAVE_ARCH_HUGE_PTE_MKUFFD_WP
87 static inline pte_t huge_pte_mkuffd_wp(pte_t pte)
88 {
89 	return pte;
90 }
91 
92 #define __HAVE_ARCH_HUGE_PTE_CLEAR_UFFD_WP
93 static inline pte_t huge_pte_clear_uffd_wp(pte_t pte)
94 {
95 	return pte;
96 }
97 
98 #define __HAVE_ARCH_HUGE_PTE_UFFD_WP
99 static inline int huge_pte_uffd_wp(pte_t pte)
100 {
101 	return 0;
102 }
103 
104 #include <asm-generic/hugetlb.h>
105 
106 #endif /* _ASM_S390_HUGETLB_H */
107