arch/nios2/include/asm/pgtable.h

   1 /*
   2  * Copyright (C) 2011 Tobias Klauser <tklauser@distanz.ch>
   3  * Copyright (C) 2009 Wind River Systems Inc
   4  *
   5  * Based on asm/pgtable-32.h from mips which is:
   6  *
   7  * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 2003 Ralf Baechle
   8  * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
   9  *
  10  * This file is subject to the terms and conditions of the GNU General Public
  11  * License.  See the file "COPYING" in the main directory of this archive
  12  * for more details.
  13  */
  14
  15 #ifndef _ASM_NIOS2_PGTABLE_H
  16 #define _ASM_NIOS2_PGTABLE_H
  17
  18 #include <linux/io.h>
  19 #include <linux/bug.h>
  20 #include <asm/page.h>
  21 #include <asm/cacheflush.h>
  22 #include <asm/tlbflush.h>
  23
  24 #include <asm/pgtable-bits.h>
  25 #include <asm-generic/pgtable-nopmd.h>
  26
  27 #define FIRST_USER_ADDRESS      0UL
  28
  29 #define VMALLOC_START           CONFIG_NIOS2_KERNEL_MMU_REGION_BASE
  30 #define VMALLOC_END             (CONFIG_NIOS2_KERNEL_REGION_BASE - 1)
  31
  32 struct mm_struct;
  33
  34 /* Helper macro */
  35 #define MKP(x, w, r) __pgprot(_PAGE_PRESENT | _PAGE_CACHED |            \
  36                                 ((x) ? _PAGE_EXEC : 0) |                \
  37                                 ((r) ? _PAGE_READ : 0) |                \
  38                                 ((w) ? _PAGE_WRITE : 0))
  39 /*
  40  * These are the macros that generic kernel code needs
  41  * (to populate protection_map[])
  42  */
  43
  44 /* Remove W bit on private pages for COW support */
  45 #define __P000  MKP(0, 0, 0)
  46 #define __P001  MKP(0, 0, 1)
  47 #define __P010  MKP(0, 0, 0)    /* COW */
  48 #define __P011  MKP(0, 0, 1)    /* COW */
  49 #define __P100  MKP(1, 0, 0)
  50 #define __P101  MKP(1, 0, 1)
  51 #define __P110  MKP(1, 0, 0)    /* COW */
  52 #define __P111  MKP(1, 0, 1)    /* COW */
  53
  54 /* Shared pages can have exact HW mapping */
  55 #define __S000  MKP(0, 0, 0)
  56 #define __S001  MKP(0, 0, 1)
  57 #define __S010  MKP(0, 1, 0)
  58 #define __S011  MKP(0, 1, 1)
  59 #define __S100  MKP(1, 0, 0)
  60 #define __S101  MKP(1, 0, 1)
  61 #define __S110  MKP(1, 1, 0)
  62 #define __S111  MKP(1, 1, 1)
  63
  64 /* Used all over the kernel */
  65 #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \
  66                              _PAGE_WRITE | _PAGE_EXEC | _PAGE_GLOBAL)
  67
  68 #define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \
  69                              _PAGE_WRITE | _PAGE_ACCESSED)
  70
  71 #define PAGE_COPY MKP(0, 0, 1)
  72
  73 #define PGD_ORDER       0
  74 #define PTE_ORDER       0
  75
  76 #define PTRS_PER_PGD    ((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t))
  77 #define PTRS_PER_PTE    ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
  78
  79 #define USER_PTRS_PER_PGD       \
  80         (CONFIG_NIOS2_KERNEL_MMU_REGION_BASE / PGDIR_SIZE)
  81
  82 #define PGDIR_SHIFT     22
  83 #define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
  84 #define PGDIR_MASK      (~(PGDIR_SIZE-1))
  85
  86 /*
  87  * ZERO_PAGE is a global shared page that is always zero: used
  88  * for zero-mapped memory areas etc..
  89  */
  90 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
  91 #define ZERO_PAGE(vaddr)        (virt_to_page(empty_zero_page))
  92
  93 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  94 extern pte_t invalid_pte_table[PAGE_SIZE/sizeof(pte_t)];
  95
  96 /*
  97  * (pmds are folded into puds so this doesn't get actually called,
  98  * but the define is needed for a generic inline function.)
  99  */
 100 static inline void set_pmd(pmd_t *pmdptr, pmd_t pmdval)
 101 {
 102         pmdptr->pud.pgd.pgd = pmdval.pud.pgd.pgd;
 103 }
 104
 105 /* to find an entry in a page-table-directory */
 106 #define pgd_index(addr)         (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
 107 #define pgd_offset(mm, addr)    ((mm)->pgd + pgd_index(addr))
 108
 109 static inline int pte_write(pte_t pte)          \
 110         { return pte_val(pte) & _PAGE_WRITE; }
 111 static inline int pte_dirty(pte_t pte)          \
 112         { return pte_val(pte) & _PAGE_DIRTY; }
 113 static inline int pte_young(pte_t pte)          \
 114         { return pte_val(pte) & _PAGE_ACCESSED; }
 115 static inline int pte_special(pte_t pte)        { return 0; }
 116
 117 #define pgprot_noncached pgprot_noncached
 118
 119 static inline pgprot_t pgprot_noncached(pgprot_t _prot)
 120 {
 121         unsigned long prot = pgprot_val(_prot);
 122
 123         prot &= ~_PAGE_CACHED;
 124
 125         return __pgprot(prot);
 126 }
 127
 128 static inline int pte_none(pte_t pte)
 129 {
 130         return !(pte_val(pte) & ~(_PAGE_GLOBAL|0xf));
 131 }
 132
 133 static inline int pte_present(pte_t pte)        \
 134         { return pte_val(pte) & _PAGE_PRESENT; }
 135
 136 /*
 137  * The following only work if pte_present() is true.
 138  * Undefined behaviour if not..
 139  */
 140 static inline pte_t pte_wrprotect(pte_t pte)
 141 {
 142         pte_val(pte) &= ~_PAGE_WRITE;
 143         return pte;
 144 }
 145
 146 static inline pte_t pte_mkclean(pte_t pte)
 147 {
 148         pte_val(pte) &= ~_PAGE_DIRTY;
 149         return pte;
 150 }
 151
 152 static inline pte_t pte_mkold(pte_t pte)
 153 {
 154         pte_val(pte) &= ~_PAGE_ACCESSED;
 155         return pte;
 156 }
 157
 158 static inline pte_t pte_mkwrite(pte_t pte)
 159 {
 160         pte_val(pte) |= _PAGE_WRITE;
 161         return pte;
 162 }
 163
 164 static inline pte_t pte_mkdirty(pte_t pte)
 165 {
 166         pte_val(pte) |= _PAGE_DIRTY;
 167         return pte;
 168 }
 169
 170 static inline pte_t pte_mkspecial(pte_t pte)    { return pte; }
 171
 172 static inline pte_t pte_mkyoung(pte_t pte)
 173 {
 174         pte_val(pte) |= _PAGE_ACCESSED;
 175         return pte;
 176 }
 177
 178 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 179 {
 180         const unsigned long mask = _PAGE_READ | _PAGE_WRITE | _PAGE_EXEC;
 181
 182         pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
 183         return pte;
 184 }
 185
 186 static inline int pmd_present(pmd_t pmd)
 187 {
 188         return (pmd_val(pmd) != (unsigned long) invalid_pte_table)
 189                         && (pmd_val(pmd) != 0UL);
 190 }
 191
 192 static inline void pmd_clear(pmd_t *pmdp)
 193 {
 194         pmd_val(*pmdp) = (unsigned long) invalid_pte_table;
 195 }
 196
 197 #define pte_pfn(pte)            (pte_val(pte) & 0xfffff)
 198 #define pfn_pte(pfn, prot)      (__pte(pfn | pgprot_val(prot)))
 199 #define pte_page(pte)           (pfn_to_page(pte_pfn(pte)))
 200
 201 /*
 202  * Store a linux PTE into the linux page table.
 203  */
 204 static inline void set_pte(pte_t *ptep, pte_t pteval)
 205 {
 206         *ptep = pteval;
 207 }
 208
 209 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 210                               pte_t *ptep, pte_t pteval)
 211 {
 212         unsigned long paddr = (unsigned long)page_to_virt(pte_page(pteval));
 213
 214         flush_dcache_range(paddr, paddr + PAGE_SIZE);
 215         set_pte(ptep, pteval);
 216 }
 217
 218 static inline int pmd_none(pmd_t pmd)
 219 {
 220         return (pmd_val(pmd) ==
 221                 (unsigned long) invalid_pte_table) || (pmd_val(pmd) == 0UL);
 222 }
 223
 224 #define pmd_bad(pmd)    (pmd_val(pmd) & ~PAGE_MASK)
 225
 226 static inline void pte_clear(struct mm_struct *mm,
 227                                 unsigned long addr, pte_t *ptep)
 228 {
 229         pte_t null;
 230
 231         pte_val(null) = (addr >> PAGE_SHIFT) & 0xf;
 232
 233         set_pte_at(mm, addr, ptep, null);
 234         flush_tlb_one(addr);
 235 }
 236
 237 /*
 238  * Conversion functions: convert a page and protection to a page entry,
 239  * and a page entry and page directory to the page they refer to.
 240  */
 241 #define mk_pte(page, prot)      (pfn_pte(page_to_pfn(page), prot))
 242
 243 #define pte_unmap(pte)  do { } while (0)
 244
 245 /*
 246  * Conversion functions: convert a page and protection to a page entry,
 247  * and a page entry and page directory to the page they refer to.
 248  */
 249 #define pmd_phys(pmd)           virt_to_phys((void *)pmd_val(pmd))
 250 #define pmd_page(pmd)           (pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
 251 #define pmd_page_vaddr(pmd)     pmd_val(pmd)
 252
 253 #define pte_offset_map(dir, addr)                       \
 254         ((pte_t *) page_address(pmd_page(*dir)) +       \
 255          (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)))
 256
 257 /* to find an entry in a kernel page-table-directory */
 258 #define pgd_offset_k(addr)      pgd_offset(&init_mm, addr)
 259
 260 /* Get the address to the PTE for a vaddr in specific directory */
 261 #define pte_offset_kernel(dir, addr)                    \
 262         ((pte_t *) pmd_page_vaddr(*(dir)) +             \
 263          (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)))
 264
 265 #define pte_ERROR(e) \
 266         pr_err("%s:%d: bad pte %08lx.\n", \
 267                 __FILE__, __LINE__, pte_val(e))
 268 #define pgd_ERROR(e) \
 269         pr_err("%s:%d: bad pgd %08lx.\n", \
 270                 __FILE__, __LINE__, pgd_val(e))
 271
 272 /*
 273  * Encode and decode a swap entry (must be !pte_none(pte) && !pte_present(pte):
 274  *
 275  * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 ...  1  0
 276  *  0  0  0  0 type.  0  0  0  0  0  0 offset.........
 277  *
 278  * This gives us up to 2**2 = 4 swap files and 2**20 * 4K = 4G per swap file.
 279  *
 280  * Note that the offset field is always non-zero, thus !pte_none(pte) is always
 281  * true.
 282  */
 283 #define __swp_type(swp)         (((swp).val >> 26) & 0x3)
 284 #define __swp_offset(swp)       ((swp).val & 0xfffff)
 285 #define __swp_entry(type, off)  ((swp_entry_t) { (((type) & 0x3) << 26) \
 286                                                  | ((off) & 0xfffff) })
 287 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
 288 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 289
 290 #define kern_addr_valid(addr)           (1)
 291
 292 #include <asm-generic/pgtable.h>
 293
 294 #define pgtable_cache_init()            do { } while (0)
 295
 296 extern void __init paging_init(void);
 297 extern void __init mmu_init(void);
 298
 299 extern void update_mmu_cache(struct vm_area_struct *vma,
 300                              unsigned long address, pte_t *pte);
 301
 302 #endif /* _ASM_NIOS2_PGTABLE_H */