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#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
  32struct 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 */
  90extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
  91#define ZERO_PAGE(vaddr)        (virt_to_page(empty_zero_page))
  92
  93extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  94extern 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 */
 100static 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
 109static inline int pte_write(pte_t pte)          \
 110        { return pte_val(pte) & _PAGE_WRITE; }
 111static inline int pte_dirty(pte_t pte)          \
 112        { return pte_val(pte) & _PAGE_DIRTY; }
 113static inline int pte_young(pte_t pte)          \
 114        { return pte_val(pte) & _PAGE_ACCESSED; }
 115static inline int pte_special(pte_t pte)        { return 0; }
 116
 117#define pgprot_noncached pgprot_noncached
 118
 119static 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
 128static inline int pte_none(pte_t pte)
 129{
 130        return !(pte_val(pte) & ~(_PAGE_GLOBAL|0xf));
 131}
 132
 133static 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 */
 140static inline pte_t pte_wrprotect(pte_t pte)
 141{
 142        pte_val(pte) &= ~_PAGE_WRITE;
 143        return pte;
 144}
 145
 146static inline pte_t pte_mkclean(pte_t pte)
 147{
 148        pte_val(pte) &= ~_PAGE_DIRTY;
 149        return pte;
 150}
 151
 152static inline pte_t pte_mkold(pte_t pte)
 153{
 154        pte_val(pte) &= ~_PAGE_ACCESSED;
 155        return pte;
 156}
 157
 158static inline pte_t pte_mkwrite(pte_t pte)
 159{
 160        pte_val(pte) |= _PAGE_WRITE;
 161        return pte;
 162}
 163
 164static inline pte_t pte_mkdirty(pte_t pte)
 165{
 166        pte_val(pte) |= _PAGE_DIRTY;
 167        return pte;
 168}
 169
 170static inline pte_t pte_mkspecial(pte_t pte)    { return pte; }
 171
 172static inline pte_t pte_mkyoung(pte_t pte)
 173{
 174        pte_val(pte) |= _PAGE_ACCESSED;
 175        return pte;
 176}
 177
 178static 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
 186static 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
 192static 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 */
 204static inline void set_pte(pte_t *ptep, pte_t pteval)
 205{
 206        *ptep = pteval;
 207}
 208
 209static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 210                              pte_t *ptep, pte_t pteval)
 211{
 212        unsigned long paddr = page_to_virt(pte_page(pteval));
 213
 214        flush_dcache_range(paddr, paddr + PAGE_SIZE);
 215        set_pte(ptep, pteval);
 216}
 217
 218static 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
 226static 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
 296extern void __init paging_init(void);
 297extern void __init mmu_init(void);
 298
 299extern void update_mmu_cache(struct vm_area_struct *vma,
 300                             unsigned long address, pte_t *pte);
 301
 302#endif /* _ASM_NIOS2_PGTABLE_H */
 303