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      0
  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_file(pte_t pte)           \
 116         { return pte_val(pte) & _PAGE_FILE; }
 117 static inline int pte_special(pte_t pte)        { return 0; }
 118
 119 #define pgprot_noncached pgprot_noncached
 120
 121 static inline pgprot_t pgprot_noncached(pgprot_t _prot)
 122 {
 123         unsigned long prot = pgprot_val(_prot);
 124
 125         prot &= ~_PAGE_CACHED;
 126
 127         return __pgprot(prot);
 128 }
 129
 130 static inline int pte_none(pte_t pte)
 131 {
 132         return !(pte_val(pte) & ~(_PAGE_GLOBAL|0xf));
 133 }
 134
 135 static inline int pte_present(pte_t pte)        \
 136         { return pte_val(pte) & _PAGE_PRESENT; }
 137
 138 /*
 139  * The following only work if pte_present() is true.
 140  * Undefined behaviour if not..
 141  */
 142 static inline pte_t pte_wrprotect(pte_t pte)
 143 {
 144         pte_val(pte) &= ~_PAGE_WRITE;
 145         return pte;
 146 }
 147
 148 static inline pte_t pte_mkclean(pte_t pte)
 149 {
 150         pte_val(pte) &= ~_PAGE_DIRTY;
 151         return pte;
 152 }
 153
 154 static inline pte_t pte_mkold(pte_t pte)
 155 {
 156         pte_val(pte) &= ~_PAGE_ACCESSED;
 157         return pte;
 158 }
 159
 160 static inline pte_t pte_mkwrite(pte_t pte)
 161 {
 162         pte_val(pte) |= _PAGE_WRITE;
 163         return pte;
 164 }
 165
 166 static inline pte_t pte_mkdirty(pte_t pte)
 167 {
 168         pte_val(pte) |= _PAGE_DIRTY;
 169         return pte;
 170 }
 171
 172 static inline pte_t pte_mkspecial(pte_t pte)    { return pte; }
 173
 174 static inline pte_t pte_mkyoung(pte_t pte)
 175 {
 176         pte_val(pte) |= _PAGE_ACCESSED;
 177         return pte;
 178 }
 179
 180 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 181 {
 182         const unsigned long mask = _PAGE_READ | _PAGE_WRITE | _PAGE_EXEC;
 183
 184         pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
 185         return pte;
 186 }
 187
 188 static inline int pmd_present(pmd_t pmd)
 189 {
 190         return (pmd_val(pmd) != (unsigned long) invalid_pte_table)
 191                         && (pmd_val(pmd) != 0UL);
 192 }
 193
 194 static inline void pmd_clear(pmd_t *pmdp)
 195 {
 196         pmd_val(*pmdp) = (unsigned long) invalid_pte_table;
 197 }
 198
 199 #define pte_pfn(pte)            (pte_val(pte) & 0xfffff)
 200 #define pfn_pte(pfn, prot)      (__pte(pfn | pgprot_val(prot)))
 201 #define pte_page(pte)           (pfn_to_page(pte_pfn(pte)))
 202
 203 /*
 204  * Store a linux PTE into the linux page table.
 205  */
 206 static inline void set_pte(pte_t *ptep, pte_t pteval)
 207 {
 208         *ptep = pteval;
 209 }
 210
 211 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 212                               pte_t *ptep, pte_t pteval)
 213 {
 214         unsigned long paddr = page_to_virt(pte_page(pteval));
 215
 216         flush_dcache_range(paddr, paddr + PAGE_SIZE);
 217         set_pte(ptep, pteval);
 218 }
 219
 220 static inline int pmd_none(pmd_t pmd)
 221 {
 222         return (pmd_val(pmd) ==
 223                 (unsigned long) invalid_pte_table) || (pmd_val(pmd) == 0UL);
 224 }
 225
 226 #define pmd_bad(pmd)    (pmd_val(pmd) & ~PAGE_MASK)
 227
 228 static inline void pte_clear(struct mm_struct *mm,
 229                                 unsigned long addr, pte_t *ptep)
 230 {
 231         pte_t null;
 232
 233         pte_val(null) = (addr >> PAGE_SHIFT) & 0xf;
 234
 235         set_pte_at(mm, addr, ptep, null);
 236         flush_tlb_one(addr);
 237 }
 238
 239 /*
 240  * Conversion functions: convert a page and protection to a page entry,
 241  * and a page entry and page directory to the page they refer to.
 242  */
 243 #define mk_pte(page, prot)      (pfn_pte(page_to_pfn(page), prot))
 244
 245 #define pte_unmap(pte)  do { } while (0)
 246
 247 /*
 248  * Conversion functions: convert a page and protection to a page entry,
 249  * and a page entry and page directory to the page they refer to.
 250  */
 251 #define pmd_phys(pmd)           virt_to_phys((void *)pmd_val(pmd))
 252 #define pmd_page(pmd)           (pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
 253 #define pmd_page_vaddr(pmd)     pmd_val(pmd)
 254
 255 #define pte_offset_map(dir, addr)                       \
 256         ((pte_t *) page_address(pmd_page(*dir)) +       \
 257          (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)))
 258
 259 /* to find an entry in a kernel page-table-directory */
 260 #define pgd_offset_k(addr)      pgd_offset(&init_mm, addr)
 261
 262 /* Get the address to the PTE for a vaddr in specific directory */
 263 #define pte_offset_kernel(dir, addr)                    \
 264         ((pte_t *) pmd_page_vaddr(*(dir)) +             \
 265          (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)))
 266
 267 #define pte_ERROR(e) \
 268         pr_err("%s:%d: bad pte %08lx.\n", \
 269                 __FILE__, __LINE__, pte_val(e))
 270 #define pgd_ERROR(e) \
 271         pr_err("%s:%d: bad pgd %08lx.\n", \
 272                 __FILE__, __LINE__, pgd_val(e))
 273
 274 /*
 275  * Encode and decode a swap entry (must be !pte_none(pte) && !pte_present(pte)
 276  * && !pte_file(pte)):
 277  *
 278  * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 ...  1  0
 279  *  0  0  0  0 type.  0  0  0  0  0  0 offset.........
 280  *
 281  * This gives us up to 2**2 = 4 swap files and 2**20 * 4K = 4G per swap file.
 282  *
 283  * Note that the offset field is always non-zero, thus !pte_none(pte) is always
 284  * true.
 285  */
 286 #define __swp_type(swp)         (((swp).val >> 26) & 0x3)
 287 #define __swp_offset(swp)       ((swp).val & 0xfffff)
 288 #define __swp_entry(type, off)  ((swp_entry_t) { (((type) & 0x3) << 26) \
 289                                                  | ((off) & 0xfffff) })
 290 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
 291 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 292
 293 /* Encode and decode a nonlinear file mapping entry */
 294 #define PTE_FILE_MAX_BITS       25
 295 #define pte_to_pgoff(pte)       (pte_val(pte) & 0x1ffffff)
 296 #define pgoff_to_pte(off)       __pte(((off) & 0x1ffffff) | _PAGE_FILE)
 297
 298 #define kern_addr_valid(addr)           (1)
 299
 300 #include <asm-generic/pgtable.h>
 301
 302 #define pgtable_cache_init()            do { } while (0)
 303
 304 extern void __init paging_init(void);
 305 extern void __init mmu_init(void);
 306
 307 extern void update_mmu_cache(struct vm_area_struct *vma,
 308                              unsigned long address, pte_t *pte);
 309
 310 #endif /* _ASM_NIOS2_PGTABLE_H */