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
  33 struct 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  */
  91 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
  92 #define ZERO_PAGE(vaddr)        (virt_to_page(empty_zero_page))
  93
  94 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  95 extern 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  */
 101 static 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
 110 static inline int pte_write(pte_t pte)          \
 111         { return pte_val(pte) & _PAGE_WRITE; }
 112 static inline int pte_dirty(pte_t pte)          \
 113         { return pte_val(pte) & _PAGE_DIRTY; }
 114 static inline int pte_young(pte_t pte)          \
 115         { return pte_val(pte) & _PAGE_ACCESSED; }
 116 static inline int pte_special(pte_t pte)        { return 0; }
 117
 118 #define pgprot_noncached pgprot_noncached
 119
 120 static 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
 129 static inline int pte_none(pte_t pte)
 130 {
 131         return !(pte_val(pte) & ~(_PAGE_GLOBAL|0xf));
 132 }
 133
 134 static 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  */
 141 static inline pte_t pte_wrprotect(pte_t pte)
 142 {
 143         pte_val(pte) &= ~_PAGE_WRITE;
 144         return pte;
 145 }
 146
 147 static inline pte_t pte_mkclean(pte_t pte)
 148 {
 149         pte_val(pte) &= ~_PAGE_DIRTY;
 150         return pte;
 151 }
 152
 153 static inline pte_t pte_mkold(pte_t pte)
 154 {
 155         pte_val(pte) &= ~_PAGE_ACCESSED;
 156         return pte;
 157 }
 158
 159 static inline pte_t pte_mkwrite(pte_t pte)
 160 {
 161         pte_val(pte) |= _PAGE_WRITE;
 162         return pte;
 163 }
 164
 165 static inline pte_t pte_mkdirty(pte_t pte)
 166 {
 167         pte_val(pte) |= _PAGE_DIRTY;
 168         return pte;
 169 }
 170
 171 static inline pte_t pte_mkspecial(pte_t pte)    { return pte; }
 172
 173 static inline pte_t pte_mkyoung(pte_t pte)
 174 {
 175         pte_val(pte) |= _PAGE_ACCESSED;
 176         return pte;
 177 }
 178
 179 static 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
 187 static 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
 193 static 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  */
 205 static inline void set_pte(pte_t *ptep, pte_t pteval)
 206 {
 207         *ptep = pteval;
 208 }
 209
 210 static 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
 219 static 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
 227 static 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
 297 extern void __init paging_init(void);
 298 extern void __init mmu_init(void);
 299
 300 extern void update_mmu_cache(struct vm_area_struct *vma,
 301                              unsigned long address, pte_t *pte);
 302
 303 #endif /* _ASM_NIOS2_PGTABLE_H */