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 void page_table_free(struct mm_struct *, unsigned long *);
23 void page_table_free_rcu(struct mmu_gather *, unsigned long *, unsigned long);
24 extern int page_table_allocate_pgste;
25 
26 int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
27 			  unsigned long key, bool nq);
28 unsigned long get_guest_storage_key(struct mm_struct *mm, unsigned long addr);
29 
clear_table(unsigned long * s,unsigned long val,size_t n)30 static inline void clear_table(unsigned long *s, unsigned long val, size_t n)
31 {
32 	typedef struct { char _[n]; } addrtype;
33 
34 	*s = val;
35 	n = (n / 256) - 1;
36 	asm volatile(
37 		"	mvc	8(248,%0),0(%0)\n"
38 		"0:	mvc	256(256,%0),0(%0)\n"
39 		"	la	%0,256(%0)\n"
40 		"	brct	%1,0b\n"
41 		: "+a" (s), "+d" (n), "=m" (*(addrtype *) s)
42 		: "m" (*(addrtype *) s));
43 }
44 
crst_table_init(unsigned long * crst,unsigned long entry)45 static inline void crst_table_init(unsigned long *crst, unsigned long entry)
46 {
47 	clear_table(crst, entry, sizeof(unsigned long)*2048);
48 }
49 
pgd_entry_type(struct mm_struct * mm)50 static inline unsigned long pgd_entry_type(struct mm_struct *mm)
51 {
52 	if (mm->context.asce_limit <= (1UL << 31))
53 		return _SEGMENT_ENTRY_EMPTY;
54 	if (mm->context.asce_limit <= (1UL << 42))
55 		return _REGION3_ENTRY_EMPTY;
56 	return _REGION2_ENTRY_EMPTY;
57 }
58 
59 int crst_table_upgrade(struct mm_struct *, unsigned long limit);
60 void crst_table_downgrade(struct mm_struct *, unsigned long limit);
61 
pud_alloc_one(struct mm_struct * mm,unsigned long address)62 static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
63 {
64 	unsigned long *table = crst_table_alloc(mm);
65 	if (table)
66 		crst_table_init(table, _REGION3_ENTRY_EMPTY);
67 	return (pud_t *) table;
68 }
69 #define pud_free(mm, pud) crst_table_free(mm, (unsigned long *) pud)
70 
pmd_alloc_one(struct mm_struct * mm,unsigned long vmaddr)71 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long vmaddr)
72 {
73 	unsigned long *table = crst_table_alloc(mm);
74 
75 	if (!table)
76 		return NULL;
77 	crst_table_init(table, _SEGMENT_ENTRY_EMPTY);
78 	if (!pgtable_pmd_page_ctor(virt_to_page(table))) {
79 		crst_table_free(mm, table);
80 		return NULL;
81 	}
82 	return (pmd_t *) table;
83 }
84 
pmd_free(struct mm_struct * mm,pmd_t * pmd)85 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
86 {
87 	pgtable_pmd_page_dtor(virt_to_page(pmd));
88 	crst_table_free(mm, (unsigned long *) pmd);
89 }
90 
pgd_populate(struct mm_struct * mm,pgd_t * pgd,pud_t * pud)91 static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pud_t *pud)
92 {
93 	pgd_val(*pgd) = _REGION2_ENTRY | __pa(pud);
94 }
95 
pud_populate(struct mm_struct * mm,pud_t * pud,pmd_t * pmd)96 static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
97 {
98 	pud_val(*pud) = _REGION3_ENTRY | __pa(pmd);
99 }
100 
pgd_alloc(struct mm_struct * mm)101 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
102 {
103 	unsigned long *table = crst_table_alloc(mm);
104 
105 	if (!table)
106 		return NULL;
107 	if (mm->context.asce_limit == (1UL << 31)) {
108 		/* Forking a compat process with 2 page table levels */
109 		if (!pgtable_pmd_page_ctor(virt_to_page(table))) {
110 			crst_table_free(mm, table);
111 			return NULL;
112 		}
113 	}
114 	return (pgd_t *) table;
115 }
116 
pgd_free(struct mm_struct * mm,pgd_t * pgd)117 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
118 {
119 	if (mm->context.asce_limit == (1UL << 31))
120 		pgtable_pmd_page_dtor(virt_to_page(pgd));
121 	crst_table_free(mm, (unsigned long *) pgd);
122 }
123 
pmd_populate(struct mm_struct * mm,pmd_t * pmd,pgtable_t pte)124 static inline void pmd_populate(struct mm_struct *mm,
125 				pmd_t *pmd, pgtable_t pte)
126 {
127 	pmd_val(*pmd) = _SEGMENT_ENTRY + __pa(pte);
128 }
129 
130 #define pmd_populate_kernel(mm, pmd, pte) pmd_populate(mm, pmd, pte)
131 
132 #define pmd_pgtable(pmd) \
133 	(pgtable_t)(pmd_val(pmd) & -sizeof(pte_t)*PTRS_PER_PTE)
134 
135 /*
136  * page table entry allocation/free routines.
137  */
138 #define pte_alloc_one_kernel(mm, vmaddr) ((pte_t *) page_table_alloc(mm))
139 #define pte_alloc_one(mm, vmaddr) ((pte_t *) page_table_alloc(mm))
140 
141 #define pte_free_kernel(mm, pte) page_table_free(mm, (unsigned long *) pte)
142 #define pte_free(mm, pte) page_table_free(mm, (unsigned long *) pte)
143 
144 extern void rcu_table_freelist_finish(void);
145 
146 #endif /* _S390_PGALLOC_H */
147