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