arch/um/include/asm/pgtable.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   4  * Copyright 2003 PathScale, Inc.
   5  * Derived from include/asm-i386/pgtable.h
   6  */
   7
   8 #ifndef __UM_PGTABLE_H
   9 #define __UM_PGTABLE_H
  10
  11 #include <asm/fixmap.h>
  12
  13 #define _PAGE_PRESENT   0x001
  14 #define _PAGE_NEWPAGE   0x002
  15 #define _PAGE_NEWPROT   0x004
  16 #define _PAGE_RW        0x020
  17 #define _PAGE_USER      0x040
  18 #define _PAGE_ACCESSED  0x080
  19 #define _PAGE_DIRTY     0x100
  20 /* If _PAGE_PRESENT is clear, we use these: */
  21 #define _PAGE_PROTNONE  0x010   /* if the user mapped it with PROT_NONE;
  22                                    pte_present gives true */
  23
  24 #ifdef CONFIG_3_LEVEL_PGTABLES
  25 #include <asm/pgtable-3level.h>
  26 #else
  27 #include <asm/pgtable-2level.h>
  28 #endif
  29
  30 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  31
  32 /* zero page used for uninitialized stuff */
  33 extern unsigned long *empty_zero_page;
  34
  35 /* Just any arbitrary offset to the start of the vmalloc VM area: the
  36  * current 8MB value just means that there will be a 8MB "hole" after the
  37  * physical memory until the kernel virtual memory starts.  That means that
  38  * any out-of-bounds memory accesses will hopefully be caught.
  39  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
  40  * area for the same reason. ;)
  41  */
  42
  43 extern unsigned long end_iomem;
  44
  45 #define VMALLOC_OFFSET  (__va_space)
  46 #define VMALLOC_START ((end_iomem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
  47 #define PKMAP_BASE ((FIXADDR_START - LAST_PKMAP * PAGE_SIZE) & PMD_MASK)
  48 #define VMALLOC_END     (FIXADDR_START-2*PAGE_SIZE)
  49 #define MODULES_VADDR   VMALLOC_START
  50 #define MODULES_END     VMALLOC_END
  51 #define MODULES_LEN     (MODULES_VADDR - MODULES_END)
  52
  53 #define _PAGE_TABLE     (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
  54 #define _KERNPG_TABLE   (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
  55 #define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
  56 #define __PAGE_KERNEL_EXEC                                              \
  57          (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
  58 #define PAGE_NONE       __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
  59 #define PAGE_SHARED     __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
  60 #define PAGE_COPY       __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
  61 #define PAGE_READONLY   __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
  62 #define PAGE_KERNEL     __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
  63 #define PAGE_KERNEL_EXEC        __pgprot(__PAGE_KERNEL_EXEC)
  64
  65 /*
  66  * The i386 can't do page protection for execute, and considers that the same
  67  * are read.
  68  * Also, write permissions imply read permissions. This is the closest we can
  69  * get..
  70  */
  71 #define __P000  PAGE_NONE
  72 #define __P001  PAGE_READONLY
  73 #define __P010  PAGE_COPY
  74 #define __P011  PAGE_COPY
  75 #define __P100  PAGE_READONLY
  76 #define __P101  PAGE_READONLY
  77 #define __P110  PAGE_COPY
  78 #define __P111  PAGE_COPY
  79
  80 #define __S000  PAGE_NONE
  81 #define __S001  PAGE_READONLY
  82 #define __S010  PAGE_SHARED
  83 #define __S011  PAGE_SHARED
  84 #define __S100  PAGE_READONLY
  85 #define __S101  PAGE_READONLY
  86 #define __S110  PAGE_SHARED
  87 #define __S111  PAGE_SHARED
  88
  89 /*
  90  * ZERO_PAGE is a global shared page that is always zero: used
  91  * for zero-mapped memory areas etc..
  92  */
  93 #define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)
  94
  95 #define pte_clear(mm,addr,xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEWPAGE))
  96
  97 #define pmd_none(x)     (!((unsigned long)pmd_val(x) & ~_PAGE_NEWPAGE))
  98 #define pmd_bad(x)      ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
  99
 100 #define pmd_present(x)  (pmd_val(x) & _PAGE_PRESENT)
 101 #define pmd_clear(xp)   do { pmd_val(*(xp)) = _PAGE_NEWPAGE; } while (0)
 102
 103 #define pmd_newpage(x)  (pmd_val(x) & _PAGE_NEWPAGE)
 104 #define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEWPAGE)
 105
 106 #define pud_newpage(x)  (pud_val(x) & _PAGE_NEWPAGE)
 107 #define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEWPAGE)
 108
 109 #define p4d_newpage(x)  (p4d_val(x) & _PAGE_NEWPAGE)
 110 #define p4d_mkuptodate(x) (p4d_val(x) &= ~_PAGE_NEWPAGE)
 111
 112 #define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
 113
 114 #define pte_page(x) pfn_to_page(pte_pfn(x))
 115
 116 #define pte_present(x)  pte_get_bits(x, (_PAGE_PRESENT | _PAGE_PROTNONE))
 117
 118 /*
 119  * =================================
 120  * Flags checking section.
 121  * =================================
 122  */
 123
 124 static inline int pte_none(pte_t pte)
 125 {
 126         return pte_is_zero(pte);
 127 }
 128
 129 /*
 130  * The following only work if pte_present() is true.
 131  * Undefined behaviour if not..
 132  */
 133 static inline int pte_read(pte_t pte)
 134 {
 135         return((pte_get_bits(pte, _PAGE_USER)) &&
 136                !(pte_get_bits(pte, _PAGE_PROTNONE)));
 137 }
 138
 139 static inline int pte_exec(pte_t pte){
 140         return((pte_get_bits(pte, _PAGE_USER)) &&
 141                !(pte_get_bits(pte, _PAGE_PROTNONE)));
 142 }
 143
 144 static inline int pte_write(pte_t pte)
 145 {
 146         return((pte_get_bits(pte, _PAGE_RW)) &&
 147                !(pte_get_bits(pte, _PAGE_PROTNONE)));
 148 }
 149
 150 static inline int pte_dirty(pte_t pte)
 151 {
 152         return pte_get_bits(pte, _PAGE_DIRTY);
 153 }
 154
 155 static inline int pte_young(pte_t pte)
 156 {
 157         return pte_get_bits(pte, _PAGE_ACCESSED);
 158 }
 159
 160 static inline int pte_newpage(pte_t pte)
 161 {
 162         return pte_get_bits(pte, _PAGE_NEWPAGE);
 163 }
 164
 165 static inline int pte_newprot(pte_t pte)
 166 {
 167         return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
 168 }
 169
 170 /*
 171  * =================================
 172  * Flags setting section.
 173  * =================================
 174  */
 175
 176 static inline pte_t pte_mknewprot(pte_t pte)
 177 {
 178         pte_set_bits(pte, _PAGE_NEWPROT);
 179         return(pte);
 180 }
 181
 182 static inline pte_t pte_mkclean(pte_t pte)
 183 {
 184         pte_clear_bits(pte, _PAGE_DIRTY);
 185         return(pte);
 186 }
 187
 188 static inline pte_t pte_mkold(pte_t pte)
 189 {
 190         pte_clear_bits(pte, _PAGE_ACCESSED);
 191         return(pte);
 192 }
 193
 194 static inline pte_t pte_wrprotect(pte_t pte)
 195 {
 196         if (likely(pte_get_bits(pte, _PAGE_RW)))
 197                 pte_clear_bits(pte, _PAGE_RW);
 198         else
 199                 return pte;
 200         return(pte_mknewprot(pte));
 201 }
 202
 203 static inline pte_t pte_mkread(pte_t pte)
 204 {
 205         if (unlikely(pte_get_bits(pte, _PAGE_USER)))
 206                 return pte;
 207         pte_set_bits(pte, _PAGE_USER);
 208         return(pte_mknewprot(pte));
 209 }
 210
 211 static inline pte_t pte_mkdirty(pte_t pte)
 212 {
 213         pte_set_bits(pte, _PAGE_DIRTY);
 214         return(pte);
 215 }
 216
 217 static inline pte_t pte_mkyoung(pte_t pte)
 218 {
 219         pte_set_bits(pte, _PAGE_ACCESSED);
 220         return(pte);
 221 }
 222
 223 static inline pte_t pte_mkwrite(pte_t pte)
 224 {
 225         if (unlikely(pte_get_bits(pte,  _PAGE_RW)))
 226                 return pte;
 227         pte_set_bits(pte, _PAGE_RW);
 228         return(pte_mknewprot(pte));
 229 }
 230
 231 static inline pte_t pte_mkuptodate(pte_t pte)
 232 {
 233         pte_clear_bits(pte, _PAGE_NEWPAGE);
 234         if(pte_present(pte))
 235                 pte_clear_bits(pte, _PAGE_NEWPROT);
 236         return(pte);
 237 }
 238
 239 static inline pte_t pte_mknewpage(pte_t pte)
 240 {
 241         pte_set_bits(pte, _PAGE_NEWPAGE);
 242         return(pte);
 243 }
 244
 245 static inline void set_pte(pte_t *pteptr, pte_t pteval)
 246 {
 247         pte_copy(*pteptr, pteval);
 248
 249         /* If it's a swap entry, it needs to be marked _PAGE_NEWPAGE so
 250          * fix_range knows to unmap it.  _PAGE_NEWPROT is specific to
 251          * mapped pages.
 252          */
 253
 254         *pteptr = pte_mknewpage(*pteptr);
 255         if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
 256 }
 257
 258 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 259                               pte_t *pteptr, pte_t pteval)
 260 {
 261         set_pte(pteptr, pteval);
 262 }
 263
 264 #define __HAVE_ARCH_PTE_SAME
 265 static inline int pte_same(pte_t pte_a, pte_t pte_b)
 266 {
 267         return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEWPAGE);
 268 }
 269
 270 /*
 271  * Conversion functions: convert a page and protection to a page entry,
 272  * and a page entry and page directory to the page they refer to.
 273  */
 274
 275 #define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
 276 #define __virt_to_page(virt) phys_to_page(__pa(virt))
 277 #define page_to_phys(page) pfn_to_phys(page_to_pfn(page))
 278 #define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
 279
 280 #define mk_pte(page, pgprot) \
 281         ({ pte_t pte;                                   \
 282                                                         \
 283         pte_set_val(pte, page_to_phys(page), (pgprot)); \
 284         if (pte_present(pte))                           \
 285                 pte_mknewprot(pte_mknewpage(pte));      \
 286         pte;})
 287
 288 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 289 {
 290         pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
 291         return pte;
 292 }
 293
 294 /*
 295  * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
 296  *
 297  * this macro returns the index of the entry in the pmd page which would
 298  * control the given virtual address
 299  */
 300 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
 301
 302 struct mm_struct;
 303 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
 304
 305 #define update_mmu_cache(vma,address,ptep) do ; while (0)
 306
 307 /* Encode and de-code a swap entry */
 308 #define __swp_type(x)                   (((x).val >> 5) & 0x1f)
 309 #define __swp_offset(x)                 ((x).val >> 11)
 310
 311 #define __swp_entry(type, offset) \
 312         ((swp_entry_t) { ((type) << 5) | ((offset) << 11) })
 313 #define __pte_to_swp_entry(pte) \
 314         ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
 315 #define __swp_entry_to_pte(x)           ((pte_t) { (x).val })
 316
 317 #define kern_addr_valid(addr) (1)
 318
 319 /* Clear a kernel PTE and flush it from the TLB */
 320 #define kpte_clear_flush(ptep, vaddr)           \
 321 do {                                            \
 322         pte_clear(&init_mm, (vaddr), (ptep));   \
 323         __flush_tlb_one((vaddr));               \
 324 } while (0)
 325
 326 #endif