LXR linux/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#define __ARCH_USE_5LEVEL_HACK
  26#include <asm-generic/pgtable-nopmd.h>
  27
  28#define FIRST_USER_ADDRESS      0UL
  29
  30#define VMALLOC_START           CONFIG_NIOS2_KERNEL_MMU_REGION_BASE
  31#define VMALLOC_END             (CONFIG_NIOS2_KERNEL_REGION_BASE - 1)
  32
  33struct mm_struct;
  34
  35/* Helper macro */
  36#define MKP(x, w, r) __pgprot(_PAGE_PRESENT | _PAGE_CACHED |            \
  37                                ((x) ? _PAGE_EXEC : 0) |                \
  38                                ((r) ? _PAGE_READ : 0) |                \
  39                                ((w) ? _PAGE_WRITE : 0))
  40/*
  41 * These are the macros that generic kernel code needs
  42 * (to populate protection_map[])
  43 */
  44
  45/* Remove W bit on private pages for COW support */
  46#define __P000  MKP(0, 0, 0)
  47#define __P001  MKP(0, 0, 1)
  48#define __P010  MKP(0, 0, 0)    /* COW */
  49#define __P011  MKP(0, 0, 1)    /* COW */
  50#define __P100  MKP(1, 0, 0)
  51#define __P101  MKP(1, 0, 1)
  52#define __P110  MKP(1, 0, 0)    /* COW */
  53#define __P111  MKP(1, 0, 1)    /* COW */
  54
  55/* Shared pages can have exact HW mapping */
  56#define __S000  MKP(0, 0, 0)
  57#define __S001  MKP(0, 0, 1)
  58#define __S010  MKP(0, 1, 0)
  59#define __S011  MKP(0, 1, 1)
  60#define __S100  MKP(1, 0, 0)
  61#define __S101  MKP(1, 0, 1)
  62#define __S110  MKP(1, 1, 0)
  63#define __S111  MKP(1, 1, 1)
  64
  65/* Used all over the kernel */
  66#define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \
  67                             _PAGE_WRITE | _PAGE_EXEC | _PAGE_GLOBAL)
  68
  69#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \
  70                             _PAGE_WRITE | _PAGE_ACCESSED)
  71
  72#define PAGE_COPY MKP(0, 0, 1)
  73
  74#define PGD_ORDER       0
  75#define PTE_ORDER       0
  76
  77#define PTRS_PER_PGD    ((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t))
  78#define PTRS_PER_PTE    ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
  79
  80#define USER_PTRS_PER_PGD       \
  81        (CONFIG_NIOS2_KERNEL_MMU_REGION_BASE / PGDIR_SIZE)
  82
  83#define PGDIR_SHIFT     22
  84#define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
  85#define PGDIR_MASK      (~(PGDIR_SIZE-1))
  86
  87/*
  88 * ZERO_PAGE is a global shared page that is always zero: used
  89 * for zero-mapped memory areas etc..
  90 */
  91extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
  92#define ZERO_PAGE(vaddr)        (virt_to_page(empty_zero_page))
  93
  94extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  95extern pte_t invalid_pte_table[PAGE_SIZE/sizeof(pte_t)];
  96
  97/*
  98 * (pmds are folded into puds so this doesn't get actually called,
  99 * but the define is needed for a generic inline function.)
 100 */
 101static inline void set_pmd(pmd_t *pmdptr, pmd_t pmdval)
 102{
 103        pmdptr->pud.pgd.pgd = pmdval.pud.pgd.pgd;
 104}
 105
 106/* to find an entry in a page-table-directory */
 107#define pgd_index(addr)         (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
 108#define pgd_offset(mm, addr)    ((mm)->pgd + pgd_index(addr))
 109
 110static inline int pte_write(pte_t pte)          \
 111        { return pte_val(pte) & _PAGE_WRITE; }
 112static inline int pte_dirty(pte_t pte)          \
 113        { return pte_val(pte) & _PAGE_DIRTY; }
 114static inline int pte_young(pte_t pte)          \
 115        { return pte_val(pte) & _PAGE_ACCESSED; }
 116static inline int pte_special(pte_t pte)        { return 0; }
 117
 118#define pgprot_noncached pgprot_noncached
 119
 120static inline pgprot_t pgprot_noncached(pgprot_t _prot)
 121{
 122        unsigned long prot = pgprot_val(_prot);
 123
 124        prot &= ~_PAGE_CACHED;
 125
 126        return __pgprot(prot);
 127}
 128
 129static inline int pte_none(pte_t pte)
 130{
 131        return !(pte_val(pte) & ~(_PAGE_GLOBAL|0xf));
 132}
 133
 134static inline int pte_present(pte_t pte)        \
 135        { return pte_val(pte) & _PAGE_PRESENT; }
 136
 137/*
 138 * The following only work if pte_present() is true.
 139 * Undefined behaviour if not..
 140 */
 141static inline pte_t pte_wrprotect(pte_t pte)
 142{
 143        pte_val(pte) &= ~_PAGE_WRITE;
 144        return pte;
 145}
 146
 147static inline pte_t pte_mkclean(pte_t pte)
 148{
 149        pte_val(pte) &= ~_PAGE_DIRTY;
 150        return pte;
 151}
 152
 153static inline pte_t pte_mkold(pte_t pte)
 154{
 155        pte_val(pte) &= ~_PAGE_ACCESSED;
 156        return pte;
 157}
 158
 159static inline pte_t pte_mkwrite(pte_t pte)
 160{
 161        pte_val(pte) |= _PAGE_WRITE;
 162        return pte;
 163}
 164
 165static inline pte_t pte_mkdirty(pte_t pte)
 166{
 167        pte_val(pte) |= _PAGE_DIRTY;
 168        return pte;
 169}
 170
 171static inline pte_t pte_mkspecial(pte_t pte)    { return pte; }
 172
 173static inline pte_t pte_mkyoung(pte_t pte)
 174{
 175        pte_val(pte) |= _PAGE_ACCESSED;
 176        return pte;
 177}
 178
 179static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 180{
 181        const unsigned long mask = _PAGE_READ | _PAGE_WRITE | _PAGE_EXEC;
 182
 183        pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
 184        return pte;
 185}
 186
 187static inline int pmd_present(pmd_t pmd)
 188{
 189        return (pmd_val(pmd) != (unsigned long) invalid_pte_table)
 190                        && (pmd_val(pmd) != 0UL);
 191}
 192
 193static inline void pmd_clear(pmd_t *pmdp)
 194{
 195        pmd_val(*pmdp) = (unsigned long) invalid_pte_table;
 196}
 197
 198#define pte_pfn(pte)            (pte_val(pte) & 0xfffff)
 199#define pfn_pte(pfn, prot)      (__pte(pfn | pgprot_val(prot)))
 200#define pte_page(pte)           (pfn_to_page(pte_pfn(pte)))
 201
 202/*
 203 * Store a linux PTE into the linux page table.
 204 */
 205static inline void set_pte(pte_t *ptep, pte_t pteval)
 206{
 207        *ptep = pteval;
 208}
 209
 210static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 211                              pte_t *ptep, pte_t pteval)
 212{
 213        unsigned long paddr = (unsigned long)page_to_virt(pte_page(pteval));
 214
 215        flush_dcache_range(paddr, paddr + PAGE_SIZE);
 216        set_pte(ptep, pteval);
 217}
 218
 219static inline int pmd_none(pmd_t pmd)
 220{
 221        return (pmd_val(pmd) ==
 222                (unsigned long) invalid_pte_table) || (pmd_val(pmd) == 0UL);
 223}
 224
 225#define pmd_bad(pmd)    (pmd_val(pmd) & ~PAGE_MASK)
 226
 227static inline void pte_clear(struct mm_struct *mm,
 228                                unsigned long addr, pte_t *ptep)
 229{
 230        pte_t null;
 231
 232        pte_val(null) = (addr >> PAGE_SHIFT) & 0xf;
 233
 234        set_pte_at(mm, addr, ptep, null);
 235        flush_tlb_one(addr);
 236}
 237
 238/*
 239 * Conversion functions: convert a page and protection to a page entry,
 240 * and a page entry and page directory to the page they refer to.
 241 */
 242#define mk_pte(page, prot)      (pfn_pte(page_to_pfn(page), prot))
 243
 244#define pte_unmap(pte)  do { } while (0)
 245
 246/*
 247 * Conversion functions: convert a page and protection to a page entry,
 248 * and a page entry and page directory to the page they refer to.
 249 */
 250#define pmd_phys(pmd)           virt_to_phys((void *)pmd_val(pmd))
 251#define pmd_page(pmd)           (pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
 252#define pmd_page_vaddr(pmd)     pmd_val(pmd)
 253
 254#define pte_offset_map(dir, addr)                       \
 255        ((pte_t *) page_address(pmd_page(*dir)) +       \
 256         (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)))
 257
 258/* to find an entry in a kernel page-table-directory */
 259#define pgd_offset_k(addr)      pgd_offset(&init_mm, addr)
 260
 261/* Get the address to the PTE for a vaddr in specific directory */
 262#define pte_offset_kernel(dir, addr)                    \
 263        ((pte_t *) pmd_page_vaddr(*(dir)) +             \
 264         (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)))
 265
 266#define pte_ERROR(e) \
 267        pr_err("%s:%d: bad pte %08lx.\n", \
 268                __FILE__, __LINE__, pte_val(e))
 269#define pgd_ERROR(e) \
 270        pr_err("%s:%d: bad pgd %08lx.\n", \
 271                __FILE__, __LINE__, pgd_val(e))
 272
 273/*
 274 * Encode and decode a swap entry (must be !pte_none(pte) && !pte_present(pte):
 275 *
 276 * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 ...  1  0
 277 *  0  0  0  0 type.  0  0  0  0  0  0 offset.........
 278 *
 279 * This gives us up to 2**2 = 4 swap files and 2**20 * 4K = 4G per swap file.
 280 *
 281 * Note that the offset field is always non-zero, thus !pte_none(pte) is always
 282 * true.
 283 */
 284#define __swp_type(swp)         (((swp).val >> 26) & 0x3)
 285#define __swp_offset(swp)       ((swp).val & 0xfffff)
 286#define __swp_entry(type, off)  ((swp_entry_t) { (((type) & 0x3) << 26) \
 287                                                 | ((off) & 0xfffff) })
 288#define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
 289#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 290
 291#define kern_addr_valid(addr)           (1)
 292
 293#include <asm-generic/pgtable.h>
 294
 295#define pgtable_cache_init()            do { } while (0)
 296
 297extern void __init paging_init(void);
 298extern void __init mmu_init(void);
 299
 300extern void update_mmu_cache(struct vm_area_struct *vma,
 301                             unsigned long address, pte_t *pte);
 302
 303#endif /* _ASM_NIOS2_PGTABLE_H */
 304