linux/arch/sh/include/asm/pgtable.h
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   1/* SPDX-License-Identifier: GPL-2.0
   2 *
   3 * This file contains the functions and defines necessary to modify and
   4 * use the SuperH page table tree.
   5 *
   6 * Copyright (C) 1999 Niibe Yutaka
   7 * Copyright (C) 2002 - 2007 Paul Mundt
   8 */
   9#ifndef __ASM_SH_PGTABLE_H
  10#define __ASM_SH_PGTABLE_H
  11
  12#ifdef CONFIG_X2TLB
  13#include <asm/pgtable-3level.h>
  14#else
  15#include <asm/pgtable-2level.h>
  16#endif
  17#include <asm/page.h>
  18#include <asm/mmu.h>
  19
  20#ifndef __ASSEMBLY__
  21#include <asm/addrspace.h>
  22#include <asm/fixmap.h>
  23
  24/*
  25 * ZERO_PAGE is a global shared page that is always zero: used
  26 * for zero-mapped memory areas etc..
  27 */
  28extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
  29#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
  30
  31#endif /* !__ASSEMBLY__ */
  32
  33/*
  34 * Effective and physical address definitions, to aid with sign
  35 * extension.
  36 */
  37#define NEFF            32
  38#define NEFF_SIGN       (1LL << (NEFF - 1))
  39#define NEFF_MASK       (-1LL << NEFF)
  40
  41static inline unsigned long long neff_sign_extend(unsigned long val)
  42{
  43        unsigned long long extended = val;
  44        return (extended & NEFF_SIGN) ? (extended | NEFF_MASK) : extended;
  45}
  46
  47#ifdef CONFIG_29BIT
  48#define NPHYS           29
  49#else
  50#define NPHYS           32
  51#endif
  52
  53#define NPHYS_SIGN      (1LL << (NPHYS - 1))
  54#define NPHYS_MASK      (-1LL << NPHYS)
  55
  56#define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
  57#define PGDIR_MASK      (~(PGDIR_SIZE-1))
  58
  59/* Entries per level */
  60#define PTRS_PER_PTE    (PAGE_SIZE / (1 << PTE_MAGNITUDE))
  61
  62#define FIRST_USER_ADDRESS      0UL
  63
  64#define PHYS_ADDR_MASK29                0x1fffffff
  65#define PHYS_ADDR_MASK32                0xffffffff
  66
  67static inline unsigned long phys_addr_mask(void)
  68{
  69        /* Is the MMU in 29bit mode? */
  70        if (__in_29bit_mode())
  71                return PHYS_ADDR_MASK29;
  72
  73        return PHYS_ADDR_MASK32;
  74}
  75
  76#define PTE_PHYS_MASK           (phys_addr_mask() & PAGE_MASK)
  77#define PTE_FLAGS_MASK          (~(PTE_PHYS_MASK) << PAGE_SHIFT)
  78
  79#ifdef CONFIG_SUPERH32
  80#define VMALLOC_START   (P3SEG)
  81#else
  82#define VMALLOC_START   (0xf0000000)
  83#endif
  84#define VMALLOC_END     (FIXADDR_START-2*PAGE_SIZE)
  85
  86#if defined(CONFIG_SUPERH32)
  87#include <asm/pgtable_32.h>
  88#else
  89#include <asm/pgtable_64.h>
  90#endif
  91
  92/*
  93 * SH-X and lower (legacy) SuperH parts (SH-3, SH-4, some SH-4A) can't do page
  94 * protection for execute, and considers it the same as a read. Also, write
  95 * permission implies read permission. This is the closest we can get..
  96 *
  97 * SH-X2 (SH7785) and later parts take this to the opposite end of the extreme,
  98 * not only supporting separate execute, read, and write bits, but having
  99 * completely separate permission bits for user and kernel space.
 100 */
 101         /*xwr*/
 102#define __P000  PAGE_NONE
 103#define __P001  PAGE_READONLY
 104#define __P010  PAGE_COPY
 105#define __P011  PAGE_COPY
 106#define __P100  PAGE_EXECREAD
 107#define __P101  PAGE_EXECREAD
 108#define __P110  PAGE_COPY
 109#define __P111  PAGE_COPY
 110
 111#define __S000  PAGE_NONE
 112#define __S001  PAGE_READONLY
 113#define __S010  PAGE_WRITEONLY
 114#define __S011  PAGE_SHARED
 115#define __S100  PAGE_EXECREAD
 116#define __S101  PAGE_EXECREAD
 117#define __S110  PAGE_RWX
 118#define __S111  PAGE_RWX
 119
 120typedef pte_t *pte_addr_t;
 121
 122#define kern_addr_valid(addr)   (1)
 123
 124#define pte_pfn(x)              ((unsigned long)(((x).pte_low >> PAGE_SHIFT)))
 125
 126struct vm_area_struct;
 127struct mm_struct;
 128
 129extern void __update_cache(struct vm_area_struct *vma,
 130                           unsigned long address, pte_t pte);
 131extern void __update_tlb(struct vm_area_struct *vma,
 132                         unsigned long address, pte_t pte);
 133
 134static inline void
 135update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
 136{
 137        pte_t pte = *ptep;
 138        __update_cache(vma, address, pte);
 139        __update_tlb(vma, address, pte);
 140}
 141
 142extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 143extern void paging_init(void);
 144extern void page_table_range_init(unsigned long start, unsigned long end,
 145                                  pgd_t *pgd);
 146
 147static inline bool __pte_access_permitted(pte_t pte, u64 prot)
 148{
 149        return (pte_val(pte) & (prot | _PAGE_SPECIAL)) == prot;
 150}
 151
 152#ifdef CONFIG_X2TLB
 153static inline bool pte_access_permitted(pte_t pte, bool write)
 154{
 155        u64 prot = _PAGE_PRESENT;
 156
 157        prot |= _PAGE_EXT(_PAGE_EXT_KERN_READ | _PAGE_EXT_USER_READ);
 158        if (write)
 159                prot |= _PAGE_EXT(_PAGE_EXT_KERN_WRITE | _PAGE_EXT_USER_WRITE);
 160        return __pte_access_permitted(pte, prot);
 161}
 162#elif defined(CONFIG_SUPERH64)
 163static inline bool pte_access_permitted(pte_t pte, bool write)
 164{
 165        u64 prot = _PAGE_PRESENT | _PAGE_USER | _PAGE_READ;
 166
 167        if (write)
 168                prot |= _PAGE_WRITE;
 169        return __pte_access_permitted(pte, prot);
 170}
 171#else
 172static inline bool pte_access_permitted(pte_t pte, bool write)
 173{
 174        u64 prot = _PAGE_PRESENT | _PAGE_USER;
 175
 176        if (write)
 177                prot |= _PAGE_RW;
 178        return __pte_access_permitted(pte, prot);
 179}
 180#endif
 181
 182#define pte_access_permitted pte_access_permitted
 183
 184/* arch/sh/mm/mmap.c */
 185#define HAVE_ARCH_UNMAPPED_AREA
 186#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 187
 188#include <asm-generic/pgtable.h>
 189
 190#endif /* __ASM_SH_PGTABLE_H */
 191