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
  30 struct 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
  44 /* Shared pages can have exact HW mapping */
  45
  46 /* Used all over the kernel */
  47 #define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \
  48                              _PAGE_WRITE | _PAGE_EXEC | _PAGE_GLOBAL)
  49
  50 #define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_CACHED | _PAGE_READ | \
  51                              _PAGE_WRITE | _PAGE_ACCESSED)
  52
  53 #define PAGE_COPY MKP(0, 0, 1)
  54
  55 #define PTRS_PER_PGD    (PAGE_SIZE / sizeof(pgd_t))
  56 #define PTRS_PER_PTE    (PAGE_SIZE / sizeof(pte_t))
  57
  58 #define USER_PTRS_PER_PGD       \
  59         (CONFIG_NIOS2_KERNEL_MMU_REGION_BASE / PGDIR_SIZE)
  60
  61 #define PGDIR_SHIFT     22
  62 #define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
  63 #define PGDIR_MASK      (~(PGDIR_SIZE-1))
  64
  65 /*
  66  * ZERO_PAGE is a global shared page that is always zero: used
  67  * for zero-mapped memory areas etc..
  68  */
  69 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
  70 #define ZERO_PAGE(vaddr)        (virt_to_page(empty_zero_page))
  71
  72 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  73 extern pte_t invalid_pte_table[PAGE_SIZE/sizeof(pte_t)];
  74
  75 /*
  76  * (pmds are folded into puds so this doesn't get actually called,
  77  * but the define is needed for a generic inline function.)
  78  */
  79 static inline void set_pmd(pmd_t *pmdptr, pmd_t pmdval)
  80 {
  81         *pmdptr = pmdval;
  82 }
  83
  84 static inline int pte_write(pte_t pte)          \
  85         { return pte_val(pte) & _PAGE_WRITE; }
  86 static inline int pte_dirty(pte_t pte)          \
  87         { return pte_val(pte) & _PAGE_DIRTY; }
  88 static inline int pte_young(pte_t pte)          \
  89         { return pte_val(pte) & _PAGE_ACCESSED; }
  90
  91 #define pgprot_noncached pgprot_noncached
  92
  93 static inline pgprot_t pgprot_noncached(pgprot_t _prot)
  94 {
  95         unsigned long prot = pgprot_val(_prot);
  96
  97         prot &= ~_PAGE_CACHED;
  98
  99         return __pgprot(prot);
 100 }
 101
 102 static inline int pte_none(pte_t pte)
 103 {
 104         return !(pte_val(pte) & ~(_PAGE_GLOBAL|0xf));
 105 }
 106
 107 static inline int pte_present(pte_t pte)        \
 108         { return pte_val(pte) & _PAGE_PRESENT; }
 109
 110 /*
 111  * The following only work if pte_present() is true.
 112  * Undefined behaviour if not..
 113  */
 114 static inline pte_t pte_wrprotect(pte_t pte)
 115 {
 116         pte_val(pte) &= ~_PAGE_WRITE;
 117         return pte;
 118 }
 119
 120 static inline pte_t pte_mkclean(pte_t pte)
 121 {
 122         pte_val(pte) &= ~_PAGE_DIRTY;
 123         return pte;
 124 }
 125
 126 static inline pte_t pte_mkold(pte_t pte)
 127 {
 128         pte_val(pte) &= ~_PAGE_ACCESSED;
 129         return pte;
 130 }
 131
 132 static inline pte_t pte_mkwrite_novma(pte_t pte)
 133 {
 134         pte_val(pte) |= _PAGE_WRITE;
 135         return pte;
 136 }
 137
 138 static inline pte_t pte_mkdirty(pte_t pte)
 139 {
 140         pte_val(pte) |= _PAGE_DIRTY;
 141         return pte;
 142 }
 143
 144 static inline pte_t pte_mkyoung(pte_t pte)
 145 {
 146         pte_val(pte) |= _PAGE_ACCESSED;
 147         return pte;
 148 }
 149
 150 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 151 {
 152         const unsigned long mask = _PAGE_READ | _PAGE_WRITE | _PAGE_EXEC;
 153
 154         pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
 155         return pte;
 156 }
 157
 158 static inline int pmd_present(pmd_t pmd)
 159 {
 160         return (pmd_val(pmd) != (unsigned long) invalid_pte_table)
 161                         && (pmd_val(pmd) != 0UL);
 162 }
 163
 164 static inline void pmd_clear(pmd_t *pmdp)
 165 {
 166         pmd_val(*pmdp) = (unsigned long) invalid_pte_table;
 167 }
 168
 169 #define pte_pfn(pte)            (pte_val(pte) & 0xfffff)
 170 #define pfn_pte(pfn, prot)      (__pte(pfn | pgprot_val(prot)))
 171 #define pte_page(pte)           (pfn_to_page(pte_pfn(pte)))
 172
 173 /*
 174  * Store a linux PTE into the linux page table.
 175  */
 176 static inline void set_pte(pte_t *ptep, pte_t pteval)
 177 {
 178         *ptep = pteval;
 179 }
 180
 181 static inline void set_ptes(struct mm_struct *mm, unsigned long addr,
 182                 pte_t *ptep, pte_t pte, unsigned int nr)
 183 {
 184         unsigned long paddr = (unsigned long)page_to_virt(pte_page(pte));
 185
 186         flush_dcache_range(paddr, paddr + nr * PAGE_SIZE);
 187         for (;;) {
 188                 set_pte(ptep, pte);
 189                 if (--nr == 0)
 190                         break;
 191                 ptep++;
 192                 pte_val(pte) += 1;
 193         }
 194 }
 195 #define set_ptes set_ptes
 196
 197 static inline int pmd_none(pmd_t pmd)
 198 {
 199         return (pmd_val(pmd) ==
 200                 (unsigned long) invalid_pte_table) || (pmd_val(pmd) == 0UL);
 201 }
 202
 203 #define pmd_bad(pmd)    (pmd_val(pmd) & ~PAGE_MASK)
 204
 205 static inline void pte_clear(struct mm_struct *mm,
 206                                 unsigned long addr, pte_t *ptep)
 207 {
 208         pte_t null;
 209
 210         pte_val(null) = (addr >> PAGE_SHIFT) & 0xf;
 211
 212         set_pte(ptep, null);
 213 }
 214
 215 /*
 216  * Conversion functions: convert a page and protection to a page entry,
 217  * and a page entry and page directory to the page they refer to.
 218  */
 219 #define mk_pte(page, prot)      (pfn_pte(page_to_pfn(page), prot))
 220
 221 /*
 222  * Conversion functions: convert a page and protection to a page entry,
 223  * and a page entry and page directory to the page they refer to.
 224  */
 225 #define pmd_phys(pmd)           virt_to_phys((void *)pmd_val(pmd))
 226 #define pmd_pfn(pmd)            (pmd_phys(pmd) >> PAGE_SHIFT)
 227 #define pmd_page(pmd)           (pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
 228
 229 static inline unsigned long pmd_page_vaddr(pmd_t pmd)
 230 {
 231         return pmd_val(pmd);
 232 }
 233
 234 #define pte_ERROR(e) \
 235         pr_err("%s:%d: bad pte %08lx.\n", \
 236                 __FILE__, __LINE__, pte_val(e))
 237 #define pgd_ERROR(e) \
 238         pr_err("%s:%d: bad pgd %08lx.\n", \
 239                 __FILE__, __LINE__, pgd_val(e))
 240
 241 /*
 242  * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
 243  * are !pte_none() && !pte_present().
 244  *
 245  * Format of swap PTEs:
 246  *
 247  *   3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
 248  *   1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
 249  *   E < type -> 0 0 0 0 0 0 <-------------- offset --------------->
 250  *
 251  *   E is the exclusive marker that is not stored in swap entries.
 252  *
 253  * Note that the offset field is always non-zero if the swap type is 0, thus
 254  * !pte_none() is always true.
 255  */
 256 #define __swp_type(swp)         (((swp).val >> 26) & 0x1f)
 257 #define __swp_offset(swp)       ((swp).val & 0xfffff)
 258 #define __swp_entry(type, off)  ((swp_entry_t) { (((type) & 0x1f) << 26) \
 259                                                  | ((off) & 0xfffff) })
 260 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
 261 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 262
 263 static inline int pte_swp_exclusive(pte_t pte)
 264 {
 265         return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;
 266 }
 267
 268 static inline pte_t pte_swp_mkexclusive(pte_t pte)
 269 {
 270         pte_val(pte) |= _PAGE_SWP_EXCLUSIVE;
 271         return pte;
 272 }
 273
 274 static inline pte_t pte_swp_clear_exclusive(pte_t pte)
 275 {
 276         pte_val(pte) &= ~_PAGE_SWP_EXCLUSIVE;
 277         return pte;
 278 }
 279
 280 extern void __init paging_init(void);
 281 extern void __init mmu_init(void);
 282
 283 void update_mmu_cache_range(struct vm_fault *vmf, struct vm_area_struct *vma,
 284                 unsigned long address, pte_t *ptep, unsigned int nr);
 285
 286 #define update_mmu_cache(vma, addr, ptep) \
 287         update_mmu_cache_range(NULL, vma, addr, ptep, 1)
 288
 289 #endif /* _ASM_NIOS2_PGTABLE_H */