xref: /openbmc/linux/arch/s390/include/asm/pgalloc.h (revision aac5987a)
1 /*
2  *  S390 version
3  *    Copyright IBM Corp. 1999, 2000
4  *    Author(s): Hartmut Penner (hp@de.ibm.com)
5  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
6  *
7  *  Derived from "include/asm-i386/pgalloc.h"
8  *    Copyright (C) 1994  Linus Torvalds
9  */
10 
11 #ifndef _S390_PGALLOC_H
12 #define _S390_PGALLOC_H
13 
14 #include <linux/threads.h>
15 #include <linux/gfp.h>
16 #include <linux/mm.h>
17 
18 unsigned long *crst_table_alloc(struct mm_struct *);
19 void crst_table_free(struct mm_struct *, unsigned long *);
20 
21 unsigned long *page_table_alloc(struct mm_struct *);
22 struct page *page_table_alloc_pgste(struct mm_struct *mm);
23 void page_table_free(struct mm_struct *, unsigned long *);
24 void page_table_free_rcu(struct mmu_gather *, unsigned long *, unsigned long);
25 void page_table_free_pgste(struct page *page);
26 extern int page_table_allocate_pgste;
27 
28 static inline void clear_table(unsigned long *s, unsigned long val, size_t n)
29 {
30 	struct addrtype { char _[256]; };
31 	int i;
32 
33 	for (i = 0; i < n; i += 256) {
34 		*s = val;
35 		asm volatile(
36 			"mvc	8(248,%[s]),0(%[s])\n"
37 			: "+m" (*(struct addrtype *) s)
38 			: [s] "a" (s));
39 		s += 256 / sizeof(long);
40 	}
41 }
42 
43 static inline void crst_table_init(unsigned long *crst, unsigned long entry)
44 {
45 	clear_table(crst, entry, sizeof(unsigned long)*2048);
46 }
47 
48 static inline unsigned long pgd_entry_type(struct mm_struct *mm)
49 {
50 	if (mm->context.asce_limit <= (1UL << 31))
51 		return _SEGMENT_ENTRY_EMPTY;
52 	if (mm->context.asce_limit <= (1UL << 42))
53 		return _REGION3_ENTRY_EMPTY;
54 	return _REGION2_ENTRY_EMPTY;
55 }
56 
57 int crst_table_upgrade(struct mm_struct *);
58 void crst_table_downgrade(struct mm_struct *);
59 
60 static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
61 {
62 	unsigned long *table = crst_table_alloc(mm);
63 	if (table)
64 		crst_table_init(table, _REGION3_ENTRY_EMPTY);
65 	return (pud_t *) table;
66 }
67 #define pud_free(mm, pud) crst_table_free(mm, (unsigned long *) pud)
68 
69 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long vmaddr)
70 {
71 	unsigned long *table = crst_table_alloc(mm);
72 
73 	if (!table)
74 		return NULL;
75 	crst_table_init(table, _SEGMENT_ENTRY_EMPTY);
76 	if (!pgtable_pmd_page_ctor(virt_to_page(table))) {
77 		crst_table_free(mm, table);
78 		return NULL;
79 	}
80 	return (pmd_t *) table;
81 }
82 
83 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
84 {
85 	pgtable_pmd_page_dtor(virt_to_page(pmd));
86 	crst_table_free(mm, (unsigned long *) pmd);
87 }
88 
89 static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pud_t *pud)
90 {
91 	pgd_val(*pgd) = _REGION2_ENTRY | __pa(pud);
92 }
93 
94 static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
95 {
96 	pud_val(*pud) = _REGION3_ENTRY | __pa(pmd);
97 }
98 
99 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
100 {
101 	unsigned long *table = crst_table_alloc(mm);
102 
103 	if (!table)
104 		return NULL;
105 	if (mm->context.asce_limit == (1UL << 31)) {
106 		/* Forking a compat process with 2 page table levels */
107 		if (!pgtable_pmd_page_ctor(virt_to_page(table))) {
108 			crst_table_free(mm, table);
109 			return NULL;
110 		}
111 	}
112 	return (pgd_t *) table;
113 }
114 
115 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
116 {
117 	if (mm->context.asce_limit == (1UL << 31))
118 		pgtable_pmd_page_dtor(virt_to_page(pgd));
119 	crst_table_free(mm, (unsigned long *) pgd);
120 }
121 
122 static inline void pmd_populate(struct mm_struct *mm,
123 				pmd_t *pmd, pgtable_t pte)
124 {
125 	pmd_val(*pmd) = _SEGMENT_ENTRY + __pa(pte);
126 }
127 
128 #define pmd_populate_kernel(mm, pmd, pte) pmd_populate(mm, pmd, pte)
129 
130 #define pmd_pgtable(pmd) \
131 	(pgtable_t)(pmd_val(pmd) & -sizeof(pte_t)*PTRS_PER_PTE)
132 
133 /*
134  * page table entry allocation/free routines.
135  */
136 #define pte_alloc_one_kernel(mm, vmaddr) ((pte_t *) page_table_alloc(mm))
137 #define pte_alloc_one(mm, vmaddr) ((pte_t *) page_table_alloc(mm))
138 
139 #define pte_free_kernel(mm, pte) page_table_free(mm, (unsigned long *) pte)
140 #define pte_free(mm, pte) page_table_free(mm, (unsigned long *) pte)
141 
142 extern void rcu_table_freelist_finish(void);
143 
144 #endif /* _S390_PGALLOC_H */
145