linux/arch/s390/include/asm/pgalloc.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2/*
   3 *  S390 version
   4 *    Copyright IBM Corp. 1999, 2000
   5 *    Author(s): Hartmut Penner (hp@de.ibm.com)
   6 *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   7 *
   8 *  Derived from "include/asm-i386/pgalloc.h"
   9 *    Copyright (C) 1994  Linus Torvalds
  10 */
  11
  12#ifndef _S390_PGALLOC_H
  13#define _S390_PGALLOC_H
  14
  15#include <linux/threads.h>
  16#include <linux/gfp.h>
  17#include <linux/mm.h>
  18
  19#define CRST_ALLOC_ORDER 2
  20
  21unsigned long *crst_table_alloc(struct mm_struct *);
  22void crst_table_free(struct mm_struct *, unsigned long *);
  23
  24unsigned long *page_table_alloc(struct mm_struct *);
  25struct page *page_table_alloc_pgste(struct mm_struct *mm);
  26void page_table_free(struct mm_struct *, unsigned long *);
  27void page_table_free_rcu(struct mmu_gather *, unsigned long *, unsigned long);
  28void page_table_free_pgste(struct page *page);
  29extern int page_table_allocate_pgste;
  30
  31static inline void clear_table(unsigned long *s, unsigned long val, size_t n)
  32{
  33        struct addrtype { char _[256]; };
  34        int i;
  35
  36        for (i = 0; i < n; i += 256) {
  37                *s = val;
  38                asm volatile(
  39                        "mvc    8(248,%[s]),0(%[s])\n"
  40                        : "+m" (*(struct addrtype *) s)
  41                        : [s] "a" (s));
  42                s += 256 / sizeof(long);
  43        }
  44}
  45
  46static inline void crst_table_init(unsigned long *crst, unsigned long entry)
  47{
  48        clear_table(crst, entry, _CRST_TABLE_SIZE);
  49}
  50
  51static inline unsigned long pgd_entry_type(struct mm_struct *mm)
  52{
  53        if (mm->context.asce_limit <= _REGION3_SIZE)
  54                return _SEGMENT_ENTRY_EMPTY;
  55        if (mm->context.asce_limit <= _REGION2_SIZE)
  56                return _REGION3_ENTRY_EMPTY;
  57        if (mm->context.asce_limit <= _REGION1_SIZE)
  58                return _REGION2_ENTRY_EMPTY;
  59        return _REGION1_ENTRY_EMPTY;
  60}
  61
  62int crst_table_upgrade(struct mm_struct *mm, unsigned long limit);
  63void crst_table_downgrade(struct mm_struct *);
  64
  65static inline p4d_t *p4d_alloc_one(struct mm_struct *mm, unsigned long address)
  66{
  67        unsigned long *table = crst_table_alloc(mm);
  68
  69        if (table)
  70                crst_table_init(table, _REGION2_ENTRY_EMPTY);
  71        return (p4d_t *) table;
  72}
  73#define p4d_free(mm, p4d) crst_table_free(mm, (unsigned long *) p4d)
  74
  75static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
  76{
  77        unsigned long *table = crst_table_alloc(mm);
  78        if (table)
  79                crst_table_init(table, _REGION3_ENTRY_EMPTY);
  80        return (pud_t *) table;
  81}
  82#define pud_free(mm, pud) crst_table_free(mm, (unsigned long *) pud)
  83
  84static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long vmaddr)
  85{
  86        unsigned long *table = crst_table_alloc(mm);
  87
  88        if (!table)
  89                return NULL;
  90        crst_table_init(table, _SEGMENT_ENTRY_EMPTY);
  91        if (!pgtable_pmd_page_ctor(virt_to_page(table))) {
  92                crst_table_free(mm, table);
  93                return NULL;
  94        }
  95        return (pmd_t *) table;
  96}
  97
  98static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
  99{
 100        pgtable_pmd_page_dtor(virt_to_page(pmd));
 101        crst_table_free(mm, (unsigned long *) pmd);
 102}
 103
 104static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, p4d_t *p4d)
 105{
 106        pgd_val(*pgd) = _REGION1_ENTRY | __pa(p4d);
 107}
 108
 109static inline void p4d_populate(struct mm_struct *mm, p4d_t *p4d, pud_t *pud)
 110{
 111        p4d_val(*p4d) = _REGION2_ENTRY | __pa(pud);
 112}
 113
 114static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
 115{
 116        pud_val(*pud) = _REGION3_ENTRY | __pa(pmd);
 117}
 118
 119static inline pgd_t *pgd_alloc(struct mm_struct *mm)
 120{
 121        unsigned long *table = crst_table_alloc(mm);
 122
 123        if (!table)
 124                return NULL;
 125        if (mm->context.asce_limit == _REGION3_SIZE) {
 126                /* Forking a compat process with 2 page table levels */
 127                if (!pgtable_pmd_page_ctor(virt_to_page(table))) {
 128                        crst_table_free(mm, table);
 129                        return NULL;
 130                }
 131        }
 132        return (pgd_t *) table;
 133}
 134
 135static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
 136{
 137        if (mm->context.asce_limit == _REGION3_SIZE)
 138                pgtable_pmd_page_dtor(virt_to_page(pgd));
 139        crst_table_free(mm, (unsigned long *) pgd);
 140}
 141
 142static inline void pmd_populate(struct mm_struct *mm,
 143                                pmd_t *pmd, pgtable_t pte)
 144{
 145        pmd_val(*pmd) = _SEGMENT_ENTRY + __pa(pte);
 146}
 147
 148#define pmd_populate_kernel(mm, pmd, pte) pmd_populate(mm, pmd, pte)
 149
 150#define pmd_pgtable(pmd) \
 151        (pgtable_t)(pmd_val(pmd) & -sizeof(pte_t)*PTRS_PER_PTE)
 152
 153/*
 154 * page table entry allocation/free routines.
 155 */
 156#define pte_alloc_one_kernel(mm, vmaddr) ((pte_t *) page_table_alloc(mm))
 157#define pte_alloc_one(mm, vmaddr) ((pte_t *) page_table_alloc(mm))
 158
 159#define pte_free_kernel(mm, pte) page_table_free(mm, (unsigned long *) pte)
 160#define pte_free(mm, pte) page_table_free(mm, (unsigned long *) pte)
 161
 162extern void rcu_table_freelist_finish(void);
 163
 164void vmem_map_init(void);
 165void *vmem_crst_alloc(unsigned long val);
 166pte_t *vmem_pte_alloc(void);
 167
 168#endif /* _S390_PGALLOC_H */
 169