include/asm-s390/pgalloc.h

   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 /*
  23  * Page allocation orders.
  24  */
  25 #ifndef __s390x__
  26 # define PTE_ALLOC_ORDER        0
  27 # define PMD_ALLOC_ORDER        0
  28 # define PGD_ALLOC_ORDER        1
  29 #else /* __s390x__ */
  30 # define PTE_ALLOC_ORDER        0
  31 # define PMD_ALLOC_ORDER        2
  32 # define PGD_ALLOC_ORDER        2
  33 #endif /* __s390x__ */
  34
  35 /*
  36  * Allocate and free page tables. The xxx_kernel() versions are
  37  * used to allocate a kernel page table - this turns on ASN bits
  38  * if any.
  39  */
  40
  41 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
  42 {
  43         pgd_t *pgd = (pgd_t *) __get_free_pages(GFP_KERNEL, PGD_ALLOC_ORDER);
  44         int i;
  45
  46         if (!pgd)
  47                 return NULL;
  48         if (s390_noexec) {
  49                 pgd_t *shadow_pgd = (pgd_t *)
  50                         __get_free_pages(GFP_KERNEL, PGD_ALLOC_ORDER);
  51                 struct page *page = virt_to_page(pgd);
  52
  53                 if (!shadow_pgd) {
  54                         free_pages((unsigned long) pgd, PGD_ALLOC_ORDER);
  55                         return NULL;
  56                 }
  57                 page->lru.next = (void *) shadow_pgd;
  58         }
  59         for (i = 0; i < PTRS_PER_PGD; i++)
  60 #ifndef __s390x__
  61                 pmd_clear(pmd_offset(pgd + i, i*PGDIR_SIZE));
  62 #else
  63                 pgd_clear(pgd + i);
  64 #endif
  65         return pgd;
  66 }
  67
  68 static inline void pgd_free(pgd_t *pgd)
  69 {
  70         pgd_t *shadow_pgd = get_shadow_pgd(pgd);
  71
  72         if (shadow_pgd)
  73                 free_pages((unsigned long) shadow_pgd, PGD_ALLOC_ORDER);
  74         free_pages((unsigned long) pgd, PGD_ALLOC_ORDER);
  75 }
  76
  77 #ifndef __s390x__
  78 /*
  79  * page middle directory allocation/free routines.
  80  * We use pmd cache only on s390x, so these are dummy routines. This
  81  * code never triggers because the pgd will always be present.
  82  */
  83 #define pmd_alloc_one(mm,address)       ({ BUG(); ((pmd_t *)2); })
  84 #define pmd_free(x)                     do { } while (0)
  85 #define __pmd_free_tlb(tlb,x)           do { } while (0)
  86 #define pgd_populate(mm, pmd, pte)      BUG()
  87 #define pgd_populate_kernel(mm, pmd, pte)       BUG()
  88 #else /* __s390x__ */
  89 static inline pmd_t * pmd_alloc_one(struct mm_struct *mm, unsigned long vmaddr)
  90 {
  91         pmd_t *pmd = (pmd_t *) __get_free_pages(GFP_KERNEL, PMD_ALLOC_ORDER);
  92         int i;
  93
  94         if (!pmd)
  95                 return NULL;
  96         if (s390_noexec) {
  97                 pmd_t *shadow_pmd = (pmd_t *)
  98                         __get_free_pages(GFP_KERNEL, PMD_ALLOC_ORDER);
  99                 struct page *page = virt_to_page(pmd);
 100
 101                 if (!shadow_pmd) {
 102                         free_pages((unsigned long) pmd, PMD_ALLOC_ORDER);
 103                         return NULL;
 104                 }
 105                 page->lru.next = (void *) shadow_pmd;
 106         }
 107         for (i=0; i < PTRS_PER_PMD; i++)
 108                 pmd_clear(pmd + i);
 109         return pmd;
 110 }
 111
 112 static inline void pmd_free (pmd_t *pmd)
 113 {
 114         pmd_t *shadow_pmd = get_shadow_pmd(pmd);
 115
 116         if (shadow_pmd)
 117                 free_pages((unsigned long) shadow_pmd, PMD_ALLOC_ORDER);
 118         free_pages((unsigned long) pmd, PMD_ALLOC_ORDER);
 119 }
 120
 121 #define __pmd_free_tlb(tlb,pmd)                 \
 122         do {                                    \
 123                 tlb_flush_mmu(tlb, 0, 0);       \
 124                 pmd_free(pmd);                  \
 125          } while (0)
 126
 127 static inline void
 128 pgd_populate_kernel(struct mm_struct *mm, pgd_t *pgd, pmd_t *pmd)
 129 {
 130         pgd_val(*pgd) = _PGD_ENTRY | __pa(pmd);
 131 }
 132
 133 static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pmd_t *pmd)
 134 {
 135         pgd_t *shadow_pgd = get_shadow_pgd(pgd);
 136         pmd_t *shadow_pmd = get_shadow_pmd(pmd);
 137
 138         if (shadow_pgd && shadow_pmd)
 139                 pgd_populate_kernel(mm, shadow_pgd, shadow_pmd);
 140         pgd_populate_kernel(mm, pgd, pmd);
 141 }
 142
 143 #endif /* __s390x__ */
 144
 145 static inline void
 146 pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd, pte_t *pte)
 147 {
 148 #ifndef __s390x__
 149         pmd_val(pmd[0]) = _PAGE_TABLE + __pa(pte);
 150         pmd_val(pmd[1]) = _PAGE_TABLE + __pa(pte+256);
 151         pmd_val(pmd[2]) = _PAGE_TABLE + __pa(pte+512);
 152         pmd_val(pmd[3]) = _PAGE_TABLE + __pa(pte+768);
 153 #else /* __s390x__ */
 154         pmd_val(*pmd) = _PMD_ENTRY + __pa(pte);
 155         pmd_val1(*pmd) = _PMD_ENTRY + __pa(pte+256);
 156 #endif /* __s390x__ */
 157 }
 158
 159 static inline void
 160 pmd_populate(struct mm_struct *mm, pmd_t *pmd, struct page *page)
 161 {
 162         pte_t *pte = (pte_t *)page_to_phys(page);
 163         pmd_t *shadow_pmd = get_shadow_pmd(pmd);
 164         pte_t *shadow_pte = get_shadow_pte(pte);
 165
 166         pmd_populate_kernel(mm, pmd, pte);
 167         if (shadow_pmd && shadow_pte)
 168                 pmd_populate_kernel(mm, shadow_pmd, shadow_pte);
 169 }
 170
 171 /*
 172  * page table entry allocation/free routines.
 173  */
 174 static inline pte_t *
 175 pte_alloc_one_kernel(struct mm_struct *mm, unsigned long vmaddr)
 176 {
 177         pte_t *pte = (pte_t *) __get_free_page(GFP_KERNEL|__GFP_REPEAT);
 178         int i;
 179
 180         if (!pte)
 181                 return NULL;
 182         if (s390_noexec) {
 183                 pte_t *shadow_pte = (pte_t *)
 184                         __get_free_page(GFP_KERNEL|__GFP_REPEAT);
 185                 struct page *page = virt_to_page(pte);
 186
 187                 if (!shadow_pte) {
 188                         free_page((unsigned long) pte);
 189                         return NULL;
 190                 }
 191                 page->lru.next = (void *) shadow_pte;
 192         }
 193         for (i=0; i < PTRS_PER_PTE; i++) {
 194                 pte_clear(mm, vmaddr, pte + i);
 195                 vmaddr += PAGE_SIZE;
 196         }
 197         return pte;
 198 }
 199
 200 static inline struct page *
 201 pte_alloc_one(struct mm_struct *mm, unsigned long vmaddr)
 202 {
 203         pte_t *pte = pte_alloc_one_kernel(mm, vmaddr);
 204         if (pte)
 205                 return virt_to_page(pte);
 206         return NULL;
 207 }
 208
 209 static inline void pte_free_kernel(pte_t *pte)
 210 {
 211         pte_t *shadow_pte = get_shadow_pte(pte);
 212
 213         if (shadow_pte)
 214                 free_page((unsigned long) shadow_pte);
 215         free_page((unsigned long) pte);
 216 }
 217
 218 static inline void pte_free(struct page *pte)
 219 {
 220         struct page *shadow_page = get_shadow_page(pte);
 221
 222         if (shadow_page)
 223                 __free_page(shadow_page);
 224         __free_page(pte);
 225 }
 226
 227 #define __pte_free_tlb(tlb, pte)                                        \
 228 ({                                                                      \
 229         struct mmu_gather *__tlb = (tlb);                               \
 230         struct page *__pte = (pte);                                     \
 231         struct page *shadow_page = get_shadow_page(__pte);              \
 232         if (shadow_page)                                                \
 233                 tlb_remove_page(__tlb, shadow_page);                    \
 234         tlb_remove_page(__tlb, __pte);                                  \
 235 })
 236
 237 #endif /* _S390_PGALLOC_H */