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 /* We borrow bit 10 to store the exclusive marker in swap PTEs. */
  25 #define _PAGE_SWP_EXCLUSIVE     0x400
  26
  27 #ifdef CONFIG_3_LEVEL_PGTABLES
  28 #include <asm/pgtable-3level.h>
  29 #else
  30 #include <asm/pgtable-2level.h>
  31 #endif
  32
  33 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  34
  35 /* zero page used for uninitialized stuff */
  36 extern unsigned long *empty_zero_page;
  37
  38 /* Just any arbitrary offset to the start of the vmalloc VM area: the
  39  * current 8MB value just means that there will be a 8MB "hole" after the
  40  * physical memory until the kernel virtual memory starts.  That means that
  41  * any out-of-bounds memory accesses will hopefully be caught.
  42  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
  43  * area for the same reason. ;)
  44  */
  45
  46 extern unsigned long end_iomem;
  47
  48 #define VMALLOC_OFFSET  (__va_space)
  49 #define VMALLOC_START ((end_iomem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
  50 #define PKMAP_BASE ((FIXADDR_START - LAST_PKMAP * PAGE_SIZE) & PMD_MASK)
  51 #define VMALLOC_END     (FIXADDR_START-2*PAGE_SIZE)
  52 #define MODULES_VADDR   VMALLOC_START
  53 #define MODULES_END     VMALLOC_END
  54 #define MODULES_LEN     (MODULES_VADDR - MODULES_END)
  55
  56 #define _PAGE_TABLE     (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
  57 #define _KERNPG_TABLE   (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
  58 #define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
  59 #define __PAGE_KERNEL_EXEC                                              \
  60          (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
  61 #define PAGE_NONE       __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
  62 #define PAGE_SHARED     __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
  63 #define PAGE_COPY       __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
  64 #define PAGE_READONLY   __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
  65 #define PAGE_KERNEL     __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
  66 #define PAGE_KERNEL_EXEC        __pgprot(__PAGE_KERNEL_EXEC)
  67
  68 /*
  69  * The i386 can't do page protection for execute, and considers that the same
  70  * are read.
  71  * Also, write permissions imply read permissions. This is the closest we can
  72  * get..
  73  */
  74
  75 /*
  76  * ZERO_PAGE is a global shared page that is always zero: used
  77  * for zero-mapped memory areas etc..
  78  */
  79 #define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)
  80
  81 #define pte_clear(mm,addr,xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEWPAGE))
  82
  83 #define pmd_none(x)     (!((unsigned long)pmd_val(x) & ~_PAGE_NEWPAGE))
  84 #define pmd_bad(x)      ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
  85
  86 #define pmd_present(x)  (pmd_val(x) & _PAGE_PRESENT)
  87 #define pmd_clear(xp)   do { pmd_val(*(xp)) = _PAGE_NEWPAGE; } while (0)
  88
  89 #define pmd_newpage(x)  (pmd_val(x) & _PAGE_NEWPAGE)
  90 #define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEWPAGE)
  91
  92 #define pud_newpage(x)  (pud_val(x) & _PAGE_NEWPAGE)
  93 #define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEWPAGE)
  94
  95 #define p4d_newpage(x)  (p4d_val(x) & _PAGE_NEWPAGE)
  96 #define p4d_mkuptodate(x) (p4d_val(x) &= ~_PAGE_NEWPAGE)
  97
  98 #define pmd_pfn(pmd) (pmd_val(pmd) >> PAGE_SHIFT)
  99 #define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
 100
 101 #define pte_page(x) pfn_to_page(pte_pfn(x))
 102
 103 #define pte_present(x)  pte_get_bits(x, (_PAGE_PRESENT | _PAGE_PROTNONE))
 104
 105 /*
 106  * =================================
 107  * Flags checking section.
 108  * =================================
 109  */
 110
 111 static inline int pte_none(pte_t pte)
 112 {
 113         return pte_is_zero(pte);
 114 }
 115
 116 /*
 117  * The following only work if pte_present() is true.
 118  * Undefined behaviour if not..
 119  */
 120 static inline int pte_read(pte_t pte)
 121 {
 122         return((pte_get_bits(pte, _PAGE_USER)) &&
 123                !(pte_get_bits(pte, _PAGE_PROTNONE)));
 124 }
 125
 126 static inline int pte_exec(pte_t pte){
 127         return((pte_get_bits(pte, _PAGE_USER)) &&
 128                !(pte_get_bits(pte, _PAGE_PROTNONE)));
 129 }
 130
 131 static inline int pte_write(pte_t pte)
 132 {
 133         return((pte_get_bits(pte, _PAGE_RW)) &&
 134                !(pte_get_bits(pte, _PAGE_PROTNONE)));
 135 }
 136
 137 static inline int pte_dirty(pte_t pte)
 138 {
 139         return pte_get_bits(pte, _PAGE_DIRTY);
 140 }
 141
 142 static inline int pte_young(pte_t pte)
 143 {
 144         return pte_get_bits(pte, _PAGE_ACCESSED);
 145 }
 146
 147 static inline int pte_newpage(pte_t pte)
 148 {
 149         return pte_get_bits(pte, _PAGE_NEWPAGE);
 150 }
 151
 152 static inline int pte_newprot(pte_t pte)
 153 {
 154         return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
 155 }
 156
 157 /*
 158  * =================================
 159  * Flags setting section.
 160  * =================================
 161  */
 162
 163 static inline pte_t pte_mknewprot(pte_t pte)
 164 {
 165         pte_set_bits(pte, _PAGE_NEWPROT);
 166         return(pte);
 167 }
 168
 169 static inline pte_t pte_mkclean(pte_t pte)
 170 {
 171         pte_clear_bits(pte, _PAGE_DIRTY);
 172         return(pte);
 173 }
 174
 175 static inline pte_t pte_mkold(pte_t pte)
 176 {
 177         pte_clear_bits(pte, _PAGE_ACCESSED);
 178         return(pte);
 179 }
 180
 181 static inline pte_t pte_wrprotect(pte_t pte)
 182 {
 183         if (likely(pte_get_bits(pte, _PAGE_RW)))
 184                 pte_clear_bits(pte, _PAGE_RW);
 185         else
 186                 return pte;
 187         return(pte_mknewprot(pte));
 188 }
 189
 190 static inline pte_t pte_mkread(pte_t pte)
 191 {
 192         if (unlikely(pte_get_bits(pte, _PAGE_USER)))
 193                 return pte;
 194         pte_set_bits(pte, _PAGE_USER);
 195         return(pte_mknewprot(pte));
 196 }
 197
 198 static inline pte_t pte_mkdirty(pte_t pte)
 199 {
 200         pte_set_bits(pte, _PAGE_DIRTY);
 201         return(pte);
 202 }
 203
 204 static inline pte_t pte_mkyoung(pte_t pte)
 205 {
 206         pte_set_bits(pte, _PAGE_ACCESSED);
 207         return(pte);
 208 }
 209
 210 static inline pte_t pte_mkwrite_novma(pte_t pte)
 211 {
 212         if (unlikely(pte_get_bits(pte,  _PAGE_RW)))
 213                 return pte;
 214         pte_set_bits(pte, _PAGE_RW);
 215         return(pte_mknewprot(pte));
 216 }
 217
 218 static inline pte_t pte_mkuptodate(pte_t pte)
 219 {
 220         pte_clear_bits(pte, _PAGE_NEWPAGE);
 221         if(pte_present(pte))
 222                 pte_clear_bits(pte, _PAGE_NEWPROT);
 223         return(pte);
 224 }
 225
 226 static inline pte_t pte_mknewpage(pte_t pte)
 227 {
 228         pte_set_bits(pte, _PAGE_NEWPAGE);
 229         return(pte);
 230 }
 231
 232 static inline void set_pte(pte_t *pteptr, pte_t pteval)
 233 {
 234         pte_copy(*pteptr, pteval);
 235
 236         /* If it's a swap entry, it needs to be marked _PAGE_NEWPAGE so
 237          * fix_range knows to unmap it.  _PAGE_NEWPROT is specific to
 238          * mapped pages.
 239          */
 240
 241         *pteptr = pte_mknewpage(*pteptr);
 242         if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
 243 }
 244
 245 #define PFN_PTE_SHIFT           PAGE_SHIFT
 246
 247 #define __HAVE_ARCH_PTE_SAME
 248 static inline int pte_same(pte_t pte_a, pte_t pte_b)
 249 {
 250         return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEWPAGE);
 251 }
 252
 253 /*
 254  * Conversion functions: convert a page and protection to a page entry,
 255  * and a page entry and page directory to the page they refer to.
 256  */
 257
 258 #define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
 259 #define __virt_to_page(virt) phys_to_page(__pa(virt))
 260 #define page_to_phys(page) pfn_to_phys(page_to_pfn(page))
 261 #define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
 262
 263 #define mk_pte(page, pgprot) \
 264         ({ pte_t pte;                                   \
 265                                                         \
 266         pte_set_val(pte, page_to_phys(page), (pgprot)); \
 267         if (pte_present(pte))                           \
 268                 pte_mknewprot(pte_mknewpage(pte));      \
 269         pte;})
 270
 271 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 272 {
 273         pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
 274         return pte;
 275 }
 276
 277 /*
 278  * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
 279  *
 280  * this macro returns the index of the entry in the pmd page which would
 281  * control the given virtual address
 282  */
 283 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
 284
 285 struct mm_struct;
 286 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
 287
 288 #define update_mmu_cache(vma,address,ptep) do {} while (0)
 289 #define update_mmu_cache_range(vmf, vma, address, ptep, nr) do {} while (0)
 290
 291 /*
 292  * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
 293  * are !pte_none() && !pte_present().
 294  *
 295  * Format of swap PTEs:
 296  *
 297  *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
 298  *   1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
 299  *   <--------------- offset ----------------> E < type -> 0 0 0 1 0
 300  *
 301  *   E is the exclusive marker that is not stored in swap entries.
 302  *   _PAGE_NEWPAGE (bit 1) is always set to 1 in set_pte().
 303  */
 304 #define __swp_type(x)                   (((x).val >> 5) & 0x1f)
 305 #define __swp_offset(x)                 ((x).val >> 11)
 306
 307 #define __swp_entry(type, offset) \
 308         ((swp_entry_t) { (((type) & 0x1f) << 5) | ((offset) << 11) })
 309 #define __pte_to_swp_entry(pte) \
 310         ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
 311 #define __swp_entry_to_pte(x)           ((pte_t) { (x).val })
 312
 313 static inline int pte_swp_exclusive(pte_t pte)
 314 {
 315         return pte_get_bits(pte, _PAGE_SWP_EXCLUSIVE);
 316 }
 317
 318 static inline pte_t pte_swp_mkexclusive(pte_t pte)
 319 {
 320         pte_set_bits(pte, _PAGE_SWP_EXCLUSIVE);
 321         return pte;
 322 }
 323
 324 static inline pte_t pte_swp_clear_exclusive(pte_t pte)
 325 {
 326         pte_clear_bits(pte, _PAGE_SWP_EXCLUSIVE);
 327         return pte;
 328 }
 329
 330 /* Clear a kernel PTE and flush it from the TLB */
 331 #define kpte_clear_flush(ptep, vaddr)           \
 332 do {                                            \
 333         pte_clear(&init_mm, (vaddr), (ptep));   \
 334         __flush_tlb_one((vaddr));               \
 335 } while (0)
 336
 337 #endif