arch/sh/include/asm/pgtable.h

   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  */
  28 extern 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
  41 static 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
  67 static 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 #define VMALLOC_START   (P3SEG)
  80 #define VMALLOC_END     (FIXADDR_START-2*PAGE_SIZE)
  81
  82 #include <asm/pgtable_32.h>
  83
  84 /*
  85  * SH-X and lower (legacy) SuperH parts (SH-3, SH-4, some SH-4A) can't do page
  86  * protection for execute, and considers it the same as a read. Also, write
  87  * permission implies read permission. This is the closest we can get..
  88  *
  89  * SH-X2 (SH7785) and later parts take this to the opposite end of the extreme,
  90  * not only supporting separate execute, read, and write bits, but having
  91  * completely separate permission bits for user and kernel space.
  92  */
  93          /*xwr*/
  94 #define __P000  PAGE_NONE
  95 #define __P001  PAGE_READONLY
  96 #define __P010  PAGE_COPY
  97 #define __P011  PAGE_COPY
  98 #define __P100  PAGE_EXECREAD
  99 #define __P101  PAGE_EXECREAD
 100 #define __P110  PAGE_COPY
 101 #define __P111  PAGE_COPY
 102
 103 #define __S000  PAGE_NONE
 104 #define __S001  PAGE_READONLY
 105 #define __S010  PAGE_WRITEONLY
 106 #define __S011  PAGE_SHARED
 107 #define __S100  PAGE_EXECREAD
 108 #define __S101  PAGE_EXECREAD
 109 #define __S110  PAGE_RWX
 110 #define __S111  PAGE_RWX
 111
 112 typedef pte_t *pte_addr_t;
 113
 114 #define kern_addr_valid(addr)   (1)
 115
 116 #define pte_pfn(x)              ((unsigned long)(((x).pte_low >> PAGE_SHIFT)))
 117
 118 struct vm_area_struct;
 119 struct mm_struct;
 120
 121 extern void __update_cache(struct vm_area_struct *vma,
 122                            unsigned long address, pte_t pte);
 123 extern void __update_tlb(struct vm_area_struct *vma,
 124                          unsigned long address, pte_t pte);
 125
 126 static inline void
 127 update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
 128 {
 129         pte_t pte = *ptep;
 130         __update_cache(vma, address, pte);
 131         __update_tlb(vma, address, pte);
 132 }
 133
 134 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 135 extern void paging_init(void);
 136 extern void page_table_range_init(unsigned long start, unsigned long end,
 137                                   pgd_t *pgd);
 138
 139 static inline bool __pte_access_permitted(pte_t pte, u64 prot)
 140 {
 141         return (pte_val(pte) & (prot | _PAGE_SPECIAL)) == prot;
 142 }
 143
 144 #ifdef CONFIG_X2TLB
 145 static inline bool pte_access_permitted(pte_t pte, bool write)
 146 {
 147         u64 prot = _PAGE_PRESENT;
 148
 149         prot |= _PAGE_EXT(_PAGE_EXT_KERN_READ | _PAGE_EXT_USER_READ);
 150         if (write)
 151                 prot |= _PAGE_EXT(_PAGE_EXT_KERN_WRITE | _PAGE_EXT_USER_WRITE);
 152         return __pte_access_permitted(pte, prot);
 153 }
 154 #else
 155 static inline bool pte_access_permitted(pte_t pte, bool write)
 156 {
 157         u64 prot = _PAGE_PRESENT | _PAGE_USER;
 158
 159         if (write)
 160                 prot |= _PAGE_RW;
 161         return __pte_access_permitted(pte, prot);
 162 }
 163 #endif
 164
 165 #define pte_access_permitted pte_access_permitted
 166
 167 /* arch/sh/mm/mmap.c */
 168 #define HAVE_ARCH_UNMAPPED_AREA
 169 #define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
 170
 171 #endif /* __ASM_SH_PGTABLE_H */