include/asm/pgtable.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 /*
0003  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
0004  * Copyright 2003 PathScale, Inc.
0005  * Derived from include/asm-i386/pgtable.h
0006  */
0007
0008 #ifndef __UM_PGTABLE_H
0009 #define __UM_PGTABLE_H
0010
0011 #include <asm/fixmap.h>
0012
0013 #define _PAGE_PRESENT   0x001
0014 #define _PAGE_NEWPAGE   0x002
0015 #define _PAGE_NEWPROT   0x004
0016 #define _PAGE_RW    0x020
0017 #define _PAGE_USER  0x040
0018 #define _PAGE_ACCESSED  0x080
0019 #define _PAGE_DIRTY 0x100
0020 /* If _PAGE_PRESENT is clear, we use these: */
0021 #define _PAGE_PROTNONE  0x010   /* if the user mapped it with PROT_NONE;
0022                    pte_present gives true */
0023
0024 #ifdef CONFIG_3_LEVEL_PGTABLES
0025 #include <asm/pgtable-3level.h>
0026 #else
0027 #include <asm/pgtable-2level.h>
0028 #endif
0029
0030 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
0031
0032 /* zero page used for uninitialized stuff */
0033 extern unsigned long *empty_zero_page;
0034
0035 /* Just any arbitrary offset to the start of the vmalloc VM area: the
0036  * current 8MB value just means that there will be a 8MB "hole" after the
0037  * physical memory until the kernel virtual memory starts.  That means that
0038  * any out-of-bounds memory accesses will hopefully be caught.
0039  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
0040  * area for the same reason. ;)
0041  */
0042
0043 extern unsigned long end_iomem;
0044
0045 #define VMALLOC_OFFSET  (__va_space)
0046 #define VMALLOC_START ((end_iomem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
0047 #define PKMAP_BASE ((FIXADDR_START - LAST_PKMAP * PAGE_SIZE) & PMD_MASK)
0048 #define VMALLOC_END (FIXADDR_START-2*PAGE_SIZE)
0049 #define MODULES_VADDR   VMALLOC_START
0050 #define MODULES_END VMALLOC_END
0051 #define MODULES_LEN (MODULES_VADDR - MODULES_END)
0052
0053 #define _PAGE_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
0054 #define _KERNPG_TABLE   (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
0055 #define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
0056 #define __PAGE_KERNEL_EXEC                                              \
0057      (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
0058 #define PAGE_NONE   __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
0059 #define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
0060 #define PAGE_COPY   __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
0061 #define PAGE_READONLY   __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
0062 #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
0063 #define PAGE_KERNEL_EXEC    __pgprot(__PAGE_KERNEL_EXEC)
0064
0065 /*
0066  * The i386 can't do page protection for execute, and considers that the same
0067  * are read.
0068  * Also, write permissions imply read permissions. This is the closest we can
0069  * get..
0070  */
0071
0072 /*
0073  * ZERO_PAGE is a global shared page that is always zero: used
0074  * for zero-mapped memory areas etc..
0075  */
0076 #define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)
0077
0078 #define pte_clear(mm,addr,xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEWPAGE))
0079
0080 #define pmd_none(x) (!((unsigned long)pmd_val(x) & ~_PAGE_NEWPAGE))
0081 #define pmd_bad(x)  ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
0082
0083 #define pmd_present(x)  (pmd_val(x) & _PAGE_PRESENT)
0084 #define pmd_clear(xp)   do { pmd_val(*(xp)) = _PAGE_NEWPAGE; } while (0)
0085
0086 #define pmd_newpage(x)  (pmd_val(x) & _PAGE_NEWPAGE)
0087 #define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEWPAGE)
0088
0089 #define pud_newpage(x)  (pud_val(x) & _PAGE_NEWPAGE)
0090 #define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEWPAGE)
0091
0092 #define p4d_newpage(x)  (p4d_val(x) & _PAGE_NEWPAGE)
0093 #define p4d_mkuptodate(x) (p4d_val(x) &= ~_PAGE_NEWPAGE)
0094
0095 #define pmd_pfn(pmd) (pmd_val(pmd) >> PAGE_SHIFT)
0096 #define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
0097
0098 #define pte_page(x) pfn_to_page(pte_pfn(x))
0099
0100 #define pte_present(x)  pte_get_bits(x, (_PAGE_PRESENT | _PAGE_PROTNONE))
0101
0102 /*
0103  * =================================
0104  * Flags checking section.
0105  * =================================
0106  */
0107
0108 static inline int pte_none(pte_t pte)
0109 {
0110     return pte_is_zero(pte);
0111 }
0112
0113 /*
0114  * The following only work if pte_present() is true.
0115  * Undefined behaviour if not..
0116  */
0117 static inline int pte_read(pte_t pte)
0118 {
0119     return((pte_get_bits(pte, _PAGE_USER)) &&
0120            !(pte_get_bits(pte, _PAGE_PROTNONE)));
0121 }
0122
0123 static inline int pte_exec(pte_t pte){
0124     return((pte_get_bits(pte, _PAGE_USER)) &&
0125            !(pte_get_bits(pte, _PAGE_PROTNONE)));
0126 }
0127
0128 static inline int pte_write(pte_t pte)
0129 {
0130     return((pte_get_bits(pte, _PAGE_RW)) &&
0131            !(pte_get_bits(pte, _PAGE_PROTNONE)));
0132 }
0133
0134 static inline int pte_dirty(pte_t pte)
0135 {
0136     return pte_get_bits(pte, _PAGE_DIRTY);
0137 }
0138
0139 static inline int pte_young(pte_t pte)
0140 {
0141     return pte_get_bits(pte, _PAGE_ACCESSED);
0142 }
0143
0144 static inline int pte_newpage(pte_t pte)
0145 {
0146     return pte_get_bits(pte, _PAGE_NEWPAGE);
0147 }
0148
0149 static inline int pte_newprot(pte_t pte)
0150 {
0151     return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
0152 }
0153
0154 /*
0155  * =================================
0156  * Flags setting section.
0157  * =================================
0158  */
0159
0160 static inline pte_t pte_mknewprot(pte_t pte)
0161 {
0162     pte_set_bits(pte, _PAGE_NEWPROT);
0163     return(pte);
0164 }
0165
0166 static inline pte_t pte_mkclean(pte_t pte)
0167 {
0168     pte_clear_bits(pte, _PAGE_DIRTY);
0169     return(pte);
0170 }
0171
0172 static inline pte_t pte_mkold(pte_t pte)
0173 {
0174     pte_clear_bits(pte, _PAGE_ACCESSED);
0175     return(pte);
0176 }
0177
0178 static inline pte_t pte_wrprotect(pte_t pte)
0179 {
0180     if (likely(pte_get_bits(pte, _PAGE_RW)))
0181         pte_clear_bits(pte, _PAGE_RW);
0182     else
0183         return pte;
0184     return(pte_mknewprot(pte));
0185 }
0186
0187 static inline pte_t pte_mkread(pte_t pte)
0188 {
0189     if (unlikely(pte_get_bits(pte, _PAGE_USER)))
0190         return pte;
0191     pte_set_bits(pte, _PAGE_USER);
0192     return(pte_mknewprot(pte));
0193 }
0194
0195 static inline pte_t pte_mkdirty(pte_t pte)
0196 {
0197     pte_set_bits(pte, _PAGE_DIRTY);
0198     return(pte);
0199 }
0200
0201 static inline pte_t pte_mkyoung(pte_t pte)
0202 {
0203     pte_set_bits(pte, _PAGE_ACCESSED);
0204     return(pte);
0205 }
0206
0207 static inline pte_t pte_mkwrite(pte_t pte)
0208 {
0209     if (unlikely(pte_get_bits(pte,  _PAGE_RW)))
0210         return pte;
0211     pte_set_bits(pte, _PAGE_RW);
0212     return(pte_mknewprot(pte));
0213 }
0214
0215 static inline pte_t pte_mkuptodate(pte_t pte)
0216 {
0217     pte_clear_bits(pte, _PAGE_NEWPAGE);
0218     if(pte_present(pte))
0219         pte_clear_bits(pte, _PAGE_NEWPROT);
0220     return(pte);
0221 }
0222
0223 static inline pte_t pte_mknewpage(pte_t pte)
0224 {
0225     pte_set_bits(pte, _PAGE_NEWPAGE);
0226     return(pte);
0227 }
0228
0229 static inline void set_pte(pte_t *pteptr, pte_t pteval)
0230 {
0231     pte_copy(*pteptr, pteval);
0232
0233     /* If it's a swap entry, it needs to be marked _PAGE_NEWPAGE so
0234      * fix_range knows to unmap it.  _PAGE_NEWPROT is specific to
0235      * mapped pages.
0236      */
0237
0238     *pteptr = pte_mknewpage(*pteptr);
0239     if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
0240 }
0241
0242 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
0243                   pte_t *pteptr, pte_t pteval)
0244 {
0245     set_pte(pteptr, pteval);
0246 }
0247
0248 #define __HAVE_ARCH_PTE_SAME
0249 static inline int pte_same(pte_t pte_a, pte_t pte_b)
0250 {
0251     return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEWPAGE);
0252 }
0253
0254 /*
0255  * Conversion functions: convert a page and protection to a page entry,
0256  * and a page entry and page directory to the page they refer to.
0257  */
0258
0259 #define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
0260 #define __virt_to_page(virt) phys_to_page(__pa(virt))
0261 #define page_to_phys(page) pfn_to_phys(page_to_pfn(page))
0262 #define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
0263
0264 #define mk_pte(page, pgprot) \
0265     ({ pte_t pte;                   \
0266                             \
0267     pte_set_val(pte, page_to_phys(page), (pgprot)); \
0268     if (pte_present(pte))               \
0269         pte_mknewprot(pte_mknewpage(pte));  \
0270     pte;})
0271
0272 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
0273 {
0274     pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
0275     return pte;
0276 }
0277
0278 /*
0279  * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
0280  *
0281  * this macro returns the index of the entry in the pmd page which would
0282  * control the given virtual address
0283  */
0284 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
0285
0286 struct mm_struct;
0287 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
0288
0289 #define update_mmu_cache(vma,address,ptep) do {} while (0)
0290
0291 /* Encode and de-code a swap entry */
0292 #define __swp_type(x)           (((x).val >> 5) & 0x1f)
0293 #define __swp_offset(x)         ((x).val >> 11)
0294
0295 #define __swp_entry(type, offset) \
0296     ((swp_entry_t) { ((type) << 5) | ((offset) << 11) })
0297 #define __pte_to_swp_entry(pte) \
0298     ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
0299 #define __swp_entry_to_pte(x)       ((pte_t) { (x).val })
0300
0301 #define kern_addr_valid(addr) (1)
0302
0303 /* Clear a kernel PTE and flush it from the TLB */
0304 #define kpte_clear_flush(ptep, vaddr)       \
0305 do {                        \
0306     pte_clear(&init_mm, (vaddr), (ptep));   \
0307     __flush_tlb_one((vaddr));       \
0308 } while (0)
0309
0310 #endif