xref: /linux/arch/s390/include/asm/pgalloc.h (revision 367b8112fe2ea5c39a7bb4d263dcdd9b612fae18)
1 /*
2  *  include/asm-s390/pgalloc.h
3  *
4  *  S390 version
5  *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
6  *    Author(s): Hartmut Penner (hp@de.ibm.com)
7  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
8  *
9  *  Derived from "include/asm-i386/pgalloc.h"
10  *    Copyright (C) 1994  Linus Torvalds
11  */
12 
13 #ifndef _S390_PGALLOC_H
14 #define _S390_PGALLOC_H
15 
16 #include <linux/threads.h>
17 #include <linux/gfp.h>
18 #include <linux/mm.h>
19 
20 #define check_pgt_cache()	do {} while (0)
21 
22 unsigned long *crst_table_alloc(struct mm_struct *, int);
23 void crst_table_free(struct mm_struct *, unsigned long *);
24 
25 unsigned long *page_table_alloc(struct mm_struct *);
26 void page_table_free(struct mm_struct *, unsigned long *);
27 void disable_noexec(struct mm_struct *, struct task_struct *);
28 
29 static inline void clear_table(unsigned long *s, unsigned long val, size_t n)
30 {
31 	*s = val;
32 	n = (n / 256) - 1;
33 	asm volatile(
34 #ifdef CONFIG_64BIT
35 		"	mvc	8(248,%0),0(%0)\n"
36 #else
37 		"	mvc	4(252,%0),0(%0)\n"
38 #endif
39 		"0:	mvc	256(256,%0),0(%0)\n"
40 		"	la	%0,256(%0)\n"
41 		"	brct	%1,0b\n"
42 		: "+a" (s), "+d" (n));
43 }
44 
45 static inline void crst_table_init(unsigned long *crst, unsigned long entry)
46 {
47 	clear_table(crst, entry, sizeof(unsigned long)*2048);
48 	crst = get_shadow_table(crst);
49 	if (crst)
50 		clear_table(crst, entry, sizeof(unsigned long)*2048);
51 }
52 
53 #ifndef __s390x__
54 
55 static inline unsigned long pgd_entry_type(struct mm_struct *mm)
56 {
57 	return _SEGMENT_ENTRY_EMPTY;
58 }
59 
60 #define pud_alloc_one(mm,address)		({ BUG(); ((pud_t *)2); })
61 #define pud_free(mm, x)				do { } while (0)
62 
63 #define pmd_alloc_one(mm,address)		({ BUG(); ((pmd_t *)2); })
64 #define pmd_free(mm, x)				do { } while (0)
65 
66 #define pgd_populate(mm, pgd, pud)		BUG()
67 #define pgd_populate_kernel(mm, pgd, pud)	BUG()
68 
69 #define pud_populate(mm, pud, pmd)		BUG()
70 #define pud_populate_kernel(mm, pud, pmd)	BUG()
71 
72 #else /* __s390x__ */
73 
74 static inline unsigned long pgd_entry_type(struct mm_struct *mm)
75 {
76 	if (mm->context.asce_limit <= (1UL << 31))
77 		return _SEGMENT_ENTRY_EMPTY;
78 	if (mm->context.asce_limit <= (1UL << 42))
79 		return _REGION3_ENTRY_EMPTY;
80 	return _REGION2_ENTRY_EMPTY;
81 }
82 
83 int crst_table_upgrade(struct mm_struct *, unsigned long limit);
84 void crst_table_downgrade(struct mm_struct *, unsigned long limit);
85 
86 static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
87 {
88 	unsigned long *table = crst_table_alloc(mm, mm->context.noexec);
89 	if (table)
90 		crst_table_init(table, _REGION3_ENTRY_EMPTY);
91 	return (pud_t *) table;
92 }
93 #define pud_free(mm, pud) crst_table_free(mm, (unsigned long *) pud)
94 
95 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long vmaddr)
96 {
97 	unsigned long *table = crst_table_alloc(mm, mm->context.noexec);
98 	if (table)
99 		crst_table_init(table, _SEGMENT_ENTRY_EMPTY);
100 	return (pmd_t *) table;
101 }
102 #define pmd_free(mm, pmd) crst_table_free(mm, (unsigned long *) pmd)
103 
104 static inline void pgd_populate_kernel(struct mm_struct *mm,
105 				       pgd_t *pgd, pud_t *pud)
106 {
107 	pgd_val(*pgd) = _REGION2_ENTRY | __pa(pud);
108 }
109 
110 static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pud_t *pud)
111 {
112 	pgd_populate_kernel(mm, pgd, pud);
113 	if (mm->context.noexec) {
114 		pgd = get_shadow_table(pgd);
115 		pud = get_shadow_table(pud);
116 		pgd_populate_kernel(mm, pgd, pud);
117 	}
118 }
119 
120 static inline void pud_populate_kernel(struct mm_struct *mm,
121 				       pud_t *pud, pmd_t *pmd)
122 {
123 	pud_val(*pud) = _REGION3_ENTRY | __pa(pmd);
124 }
125 
126 static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
127 {
128 	pud_populate_kernel(mm, pud, pmd);
129 	if (mm->context.noexec) {
130 		pud = get_shadow_table(pud);
131 		pmd = get_shadow_table(pmd);
132 		pud_populate_kernel(mm, pud, pmd);
133 	}
134 }
135 
136 #endif /* __s390x__ */
137 
138 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
139 {
140 	INIT_LIST_HEAD(&mm->context.crst_list);
141 	INIT_LIST_HEAD(&mm->context.pgtable_list);
142 	return (pgd_t *) crst_table_alloc(mm, s390_noexec);
143 }
144 #define pgd_free(mm, pgd) crst_table_free(mm, (unsigned long *) pgd)
145 
146 static inline void pmd_populate_kernel(struct mm_struct *mm,
147 				       pmd_t *pmd, pte_t *pte)
148 {
149 	pmd_val(*pmd) = _SEGMENT_ENTRY + __pa(pte);
150 }
151 
152 static inline void pmd_populate(struct mm_struct *mm,
153 				pmd_t *pmd, pgtable_t pte)
154 {
155 	pmd_populate_kernel(mm, pmd, pte);
156 	if (mm->context.noexec) {
157 		pmd = get_shadow_table(pmd);
158 		pmd_populate_kernel(mm, pmd, pte + PTRS_PER_PTE);
159 	}
160 }
161 
162 #define pmd_pgtable(pmd) \
163 	(pgtable_t)(pmd_val(pmd) & -sizeof(pte_t)*PTRS_PER_PTE)
164 
165 /*
166  * page table entry allocation/free routines.
167  */
168 #define pte_alloc_one_kernel(mm, vmaddr) ((pte_t *) page_table_alloc(mm))
169 #define pte_alloc_one(mm, vmaddr) ((pte_t *) page_table_alloc(mm))
170 
171 #define pte_free_kernel(mm, pte) page_table_free(mm, (unsigned long *) pte)
172 #define pte_free(mm, pte) page_table_free(mm, (unsigned long *) pte)
173 
174 #endif /* _S390_PGALLOC_H */
175