include/asm-m68k/pgtable.h

   1 #ifndef _M68K_PGTABLE_H
   2 #define _M68K_PGTABLE_H
   3
   4 #include <linux/config.h>
   5 #include <asm/setup.h>
   6
   7 #ifndef __ASSEMBLY__
   8 #include <asm/processor.h>
   9 #include <linux/threads.h>
  10
  11 /*
  12  * This file contains the functions and defines necessary to modify and use
  13  * the m68k page table tree.
  14  */
  15
  16 #include <asm/virtconvert.h>
  17
  18 /* Certain architectures need to do special things when pte's
  19  * within a page table are directly modified.  Thus, the following
  20  * hook is made available.
  21  */
  22 #define set_pte(pteptr, pteval)                                 \
  23         do{                                                     \
  24                 *(pteptr) = (pteval);                           \
  25         } while(0)
  26
  27
  28 /* PMD_SHIFT determines the size of the area a second-level page table can map */
  29 #define PMD_SHIFT       22
  30 #define PMD_SIZE        (1UL << PMD_SHIFT)
  31 #define PMD_MASK        (~(PMD_SIZE-1))
  32
  33 /* PGDIR_SHIFT determines what a third-level page table entry can map */
  34 #define PGDIR_SHIFT     25
  35 #define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
  36 #define PGDIR_MASK      (~(PGDIR_SIZE-1))
  37
  38 /*
  39  * entries per page directory level: the m68k is configured as three-level,
  40  * so we do have PMD level physically.
  41  */
  42 #define PTRS_PER_PTE    1024
  43 #define PTRS_PER_PMD    8
  44 #define PTRS_PER_PGD    128
  45 #define USER_PTRS_PER_PGD       (TASK_SIZE/PGDIR_SIZE)
  46 #define FIRST_USER_PGD_NR       0
  47
  48 /* Virtual address region for use by kernel_map() */
  49 #define KMAP_START      0xd0000000
  50 #define KMAP_END        0xf0000000
  51
  52 /* Just any arbitrary offset to the start of the vmalloc VM area: the
  53  * current 8MB value just means that there will be a 8MB "hole" after the
  54  * physical memory until the kernel virtual memory starts.  That means that
  55  * any out-of-bounds memory accesses will hopefully be caught.
  56  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
  57  * area for the same reason. ;)
  58  */
  59 #define VMALLOC_OFFSET  (8*1024*1024)
  60 #define VMALLOC_START (((unsigned long) high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
  61 #define VMALLOC_VMADDR(x) ((unsigned long)(x))
  62 #define VMALLOC_END KMAP_START
  63
  64 #endif /* __ASSEMBLY__ */
  65
  66 /*
  67  * Definitions for MMU descriptors
  68  */
  69 #define _PAGE_PRESENT   0x001
  70 #define _PAGE_SHORT     0x002
  71 #define _PAGE_RONLY     0x004
  72 #define _PAGE_ACCESSED  0x008
  73 #define _PAGE_DIRTY     0x010
  74 #define _PAGE_SUPER     0x080   /* 68040 supervisor only */
  75 #define _PAGE_FAKE_SUPER 0x200  /* fake supervisor only on 680[23]0 */
  76 #define _PAGE_GLOBAL040 0x400   /* 68040 global bit, used for kva descs */
  77 #define _PAGE_COW       0x800   /* implemented in software */
  78 #define _PAGE_NOCACHE030 0x040  /* 68030 no-cache mode */
  79 #define _PAGE_NOCACHE   0x060   /* 68040 cache mode, non-serialized */
  80 #define _PAGE_NOCACHE_S 0x040   /* 68040 no-cache mode, serialized */
  81 #define _PAGE_CACHE040  0x020   /* 68040 cache mode, cachable, copyback */
  82 #define _PAGE_CACHE040W 0x000   /* 68040 cache mode, cachable, write-through */
  83
  84 /* Page protection values within PTE. */
  85 #define SUN3_PAGE_VALID     (0x80000000)
  86 #define SUN3_PAGE_WRITEABLE (0x40000000)
  87 #define SUN3_PAGE_SYSTEM    (0x20000000)
  88 #define SUN3_PAGE_NOCACHE   (0x10000000)
  89 #define SUN3_PAGE_ACCESSED  (0x02000000)
  90 #define SUN3_PAGE_MODIFIED  (0x01000000)
  91
  92 #define _DESCTYPE_MASK  0x003
  93
  94 #define _CACHEMASK040   (~0x060)
  95 #define _TABLE_MASK     (0xfffffe00)
  96
  97 #define _PAGE_TABLE     (_PAGE_SHORT)
  98 #define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_NOCACHE)
  99
 100 #ifndef __ASSEMBLY__
 101
 102 /* This is the cache mode to be used for pages containing page descriptors for
 103  * processors >= '040. It is in pte_mknocache(), and the variable is defined
 104  * and initialized in head.S */
 105 extern int m68k_pgtable_cachemode;
 106
 107 /* This is the cache mode for normal pages, for supervisor access on
 108  * processors >= '040. It is used in pte_mkcache(), and the variable is
 109  * defined and initialized in head.S */
 110
 111 #if defined(CONFIG_060_WRITETHROUGH)
 112 extern int m68k_supervisor_cachemode;
 113 #else
 114 #define m68k_supervisor_cachemode _PAGE_CACHE040
 115 #endif
 116
 117 #if defined(CPU_M68040_OR_M68060_ONLY)
 118 #define mm_cachebits _PAGE_CACHE040
 119 #elif defined(CPU_M68020_OR_M68030_ONLY)
 120 #define mm_cachebits 0
 121 #else
 122 extern unsigned long mm_cachebits;
 123 #endif
 124
 125 #define PAGE_NONE       __pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED | mm_cachebits)
 126 #define PAGE_SHARED     __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | mm_cachebits)
 127 #define PAGE_COPY       __pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED | mm_cachebits)
 128 #define PAGE_READONLY   __pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED | mm_cachebits)
 129 #define PAGE_KERNEL     __pgprot(_PAGE_PRESENT | _PAGE_DIRTY | _PAGE_ACCESSED | mm_cachebits)
 130
 131 /* Alternate definitions that are compile time constants, for
 132    initializing protection_map.  The cachebits are fixed later.  */
 133 #define PAGE_NONE_C     __pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED)
 134 #define PAGE_SHARED_C   __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED)
 135 #define PAGE_COPY_C     __pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED)
 136 #define PAGE_READONLY_C __pgprot(_PAGE_PRESENT | _PAGE_RONLY | _PAGE_ACCESSED)
 137
 138 /*
 139  * The m68k can't do page protection for execute, and considers that the same are read.
 140  * Also, write permissions imply read permissions. This is the closest we can get..
 141  */
 142 #define __P000  PAGE_NONE_C
 143 #define __P001  PAGE_READONLY_C
 144 #define __P010  PAGE_COPY_C
 145 #define __P011  PAGE_COPY_C
 146 #define __P100  PAGE_READONLY_C
 147 #define __P101  PAGE_READONLY_C
 148 #define __P110  PAGE_COPY_C
 149 #define __P111  PAGE_COPY_C
 150
 151 #define __S000  PAGE_NONE_C
 152 #define __S001  PAGE_READONLY_C
 153 #define __S010  PAGE_SHARED_C
 154 #define __S011  PAGE_SHARED_C
 155 #define __S100  PAGE_READONLY_C
 156 #define __S101  PAGE_READONLY_C
 157 #define __S110  PAGE_SHARED_C
 158 #define __S111  PAGE_SHARED_C
 159
 160 /* zero page used for uninitialized stuff */
 161 extern unsigned long empty_zero_page;
 162
 163 /*
 164  * BAD_PAGETABLE is used when we need a bogus page-table, while
 165  * BAD_PAGE is used for a bogus page.
 166  *
 167  * ZERO_PAGE is a global shared page that is always zero: used
 168  * for zero-mapped memory areas etc..
 169  */
 170 extern pte_t __bad_page(void);
 171 extern pte_t * __bad_pagetable(void);
 172
 173 #define BAD_PAGETABLE __bad_pagetable()
 174 #define BAD_PAGE __bad_page()
 175 #define ZERO_PAGE(vaddr)        (virt_to_page(empty_zero_page))
 176
 177 /* number of bits that fit into a memory pointer */
 178 #define BITS_PER_PTR                    (8*sizeof(unsigned long))
 179
 180 /* to align the pointer to a pointer address */
 181 #define PTR_MASK                        (~(sizeof(void*)-1))
 182
 183 /* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */
 184 /* 64-bit machines, beware!  SRB. */
 185 #define SIZEOF_PTR_LOG2                 2
 186
 187 /*
 188  * Conversion functions: convert a page and protection to a page entry,
 189  * and a page entry and page directory to the page they refer to.
 190  */
 191 #define __mk_pte(page, pgprot) \
 192 ({                                                                      \
 193         pte_t __pte;                                                    \
 194                                                                         \
 195         pte_val(__pte) = __pa((page) + pgprot_val(pgprot);              \
 196         __pte;                                                          \
 197 })
 198 #define mk_pte(page, pgprot) __mk_pte(page_address(page), (pgprot))
 199 #define mk_pte_phys(physpage, pgprot) \
 200 ({                                                                      \
 201         pte_t __pte;                                                    \
 202                                                                         \
 203         pte_val(__pte) = (physpage) + pgprot_val(pgprot);               \
 204         __pte;                                                          \
 205 })
 206
 207 extern inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 208 { pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot); return pte; }
 209
 210 extern inline void pmd_set(pmd_t * pmdp, pte_t * ptep)
 211 {
 212         unsigned long ptbl = virt_to_phys(ptep) | _PAGE_TABLE | _PAGE_ACCESSED;
 213         unsigned long *ptr = pmdp->pmd;
 214         short i = 16;
 215         while (--i >= 0) {
 216                 *ptr++ = ptbl;
 217                 ptbl += (sizeof(pte_t)*PTRS_PER_PTE/16);
 218         }
 219 }
 220
 221 extern inline void pgd_set(pgd_t * pgdp, pmd_t * pmdp)
 222 { pgd_val(*pgdp) = _PAGE_TABLE | _PAGE_ACCESSED | __pa(pmdp); }
 223
 224 #define __pte_page(pte) ((unsigned long)__va(pte_val(pte) & PAGE_MASK))
 225 #define __pmd_page(pmd) ((unsigned long)__va(pmd_val(pmd) & _TABLE_MASK))
 226 #define __pgd_page(pgd) ((unsigned long)__va(pgd_val(pgd) & _TABLE_MASK))
 227
 228 #define pte_none(pte)           (!pte_val(pte))
 229 #define pte_present(pte)        (pte_val(pte) & (_PAGE_PRESENT | _PAGE_FAKE_SUPER))
 230 #define pte_clear(ptep)         ({ pte_val(*(ptep)) = 0; })
 231
 232 #define pmd_none(pmd)           (!pmd_val(pmd))
 233 #define pmd_bad(pmd)            ((pmd_val(pmd) & _DESCTYPE_MASK) != _PAGE_TABLE)
 234 #define pmd_present(pmd)        (pmd_val(pmd) & _PAGE_TABLE)
 235 #define pmd_clear(pmdp) ({                      \
 236         unsigned long *__ptr = pmdp->pmd;       \
 237         short __i = 16;                         \
 238         while (--__i >= 0)                      \
 239                 *__ptr++ = 0;                   \
 240 })
 241
 242 #define pgd_none(pgd)           (!pgd_val(pgd))
 243 #define pgd_bad(pgd)            ((pgd_val(pgd) & _DESCTYPE_MASK) != _PAGE_TABLE)
 244 #define pgd_present(pgd)        (pgd_val(pgd) & _PAGE_TABLE)
 245 #define pgd_clear(pgdp)         ({ pgd_val(*pgdp) = 0; })
 246
 247 /* Permanent address of a page. */
 248 #define page_address(page)      ((page)->virtual)
 249 #define __page_address(page)    (PAGE_OFFSET + (((page) - mem_map) << PAGE_SHIFT))
 250 #define pte_page(pte)           (mem_map+((__pte_page(pte) - PAGE_OFFSET) >> PAGE_SHIFT))
 251
 252 #define pte_ERROR(e) \
 253         printk("%s:%d: bad pte %p(%08lx).\n", __FILE__, __LINE__, &(e), pte_val(e))
 254 #define pmd_ERROR(e) \
 255         printk("%s:%d: bad pmd %p(%08lx).\n", __FILE__, __LINE__, &(e), pmd_val(e))
 256 #define pgd_ERROR(e) \
 257         printk("%s:%d: bad pgd %p(%08lx).\n", __FILE__, __LINE__, &(e), pgd_val(e))
 258
 259 /*
 260  * The following only work if pte_present() is true.
 261  * Undefined behaviour if not..
 262  */
 263 extern inline int pte_read(pte_t pte)           { return 1; }
 264 extern inline int pte_write(pte_t pte)          { return !(pte_val(pte) & _PAGE_RONLY); }
 265 extern inline int pte_exec(pte_t pte)           { return 1; }
 266 extern inline int pte_dirty(pte_t pte)          { return pte_val(pte) & _PAGE_DIRTY; }
 267 extern inline int pte_young(pte_t pte)          { return pte_val(pte) & _PAGE_ACCESSED; }
 268
 269 extern inline pte_t pte_wrprotect(pte_t pte)    { pte_val(pte) |= _PAGE_RONLY; return pte; }
 270 extern inline pte_t pte_rdprotect(pte_t pte)    { return pte; }
 271 extern inline pte_t pte_exprotect(pte_t pte)    { return pte; }
 272 extern inline pte_t pte_mkclean(pte_t pte)      { pte_val(pte) &= ~_PAGE_DIRTY; return pte; }
 273 extern inline pte_t pte_mkold(pte_t pte)        { pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
 274 extern inline pte_t pte_mkwrite(pte_t pte)      { pte_val(pte) &= ~_PAGE_RONLY; return pte; }
 275 extern inline pte_t pte_mkread(pte_t pte)       { return pte; }
 276 extern inline pte_t pte_mkexec(pte_t pte)       { return pte; }
 277 extern inline pte_t pte_mkdirty(pte_t pte)      { pte_val(pte) |= _PAGE_DIRTY; return pte; }
 278 extern inline pte_t pte_mkyoung(pte_t pte)      { pte_val(pte) |= _PAGE_ACCESSED; return pte; }
 279 extern inline pte_t pte_mknocache(pte_t pte)
 280 {
 281         pte_val(pte) = (pte_val(pte) & _CACHEMASK040) | m68k_pgtable_cachemode;
 282         return pte;
 283 }
 284 extern inline pte_t pte_mkcache(pte_t pte)      { pte_val(pte) = (pte_val(pte) & _CACHEMASK040) | m68k_supervisor_cachemode; return pte; }
 285
 286 #define PAGE_DIR_OFFSET(tsk,address) pgd_offset((tsk),(address))
 287
 288 #define pgd_index(address)      ((address) >> PGDIR_SHIFT)
 289
 290 /* to find an entry in a page-table-directory */
 291 extern inline pgd_t * pgd_offset(struct mm_struct * mm, unsigned long address)
 292 {
 293         return mm->pgd + pgd_index(address);
 294 }
 295
 296 #define swapper_pg_dir kernel_pg_dir
 297 extern pgd_t kernel_pg_dir[128];
 298
 299 extern inline pgd_t * pgd_offset_k(unsigned long address)
 300 {
 301         return kernel_pg_dir + (address >> PGDIR_SHIFT);
 302 }
 303
 304
 305 /* Find an entry in the second-level page table.. */
 306 extern inline pmd_t * pmd_offset(pgd_t * dir, unsigned long address)
 307 {
 308         return (pmd_t *)__pgd_page(*dir) + ((address >> PMD_SHIFT) & (PTRS_PER_PMD-1));
 309 }
 310
 311 /* Find an entry in the third-level page table.. */
 312 extern inline pte_t * pte_offset(pmd_t * pmdp, unsigned long address)
 313 {
 314         return (pte_t *)__pmd_page(*pmdp) + ((address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1));
 315 }
 316
 317 /*
 318  * Allocate and free page tables. The xxx_kernel() versions are
 319  * used to allocate a kernel page table - this turns on ASN bits
 320  * if any.
 321  */
 322
 323 /* Prior to calling these routines, the page should have been flushed
 324  * from both the cache and ATC, or the CPU might not notice that the
 325  * cache setting for the page has been changed. -jskov
 326  */
 327 static inline void nocache_page (unsigned long vaddr)
 328 {
 329         if (CPU_IS_040_OR_060) {
 330                 pgd_t *dir;
 331                 pmd_t *pmdp;
 332                 pte_t *ptep;
 333
 334                 dir = pgd_offset_k(vaddr);
 335                 pmdp = pmd_offset(dir,vaddr);
 336                 ptep = pte_offset(pmdp,vaddr);
 337                 *ptep = pte_mknocache(*ptep);
 338         }
 339 }
 340
 341 static inline void cache_page (unsigned long vaddr)
 342 {
 343         if (CPU_IS_040_OR_060) {
 344                 pgd_t *dir;
 345                 pmd_t *pmdp;
 346                 pte_t *ptep;
 347
 348                 dir = pgd_offset_k(vaddr);
 349                 pmdp = pmd_offset(dir,vaddr);
 350                 ptep = pte_offset(pmdp,vaddr);
 351                 *ptep = pte_mkcache(*ptep);
 352         }
 353 }
 354
 355
 356 /*
 357  * Check if the addr/len goes up to the end of a physical
 358  * memory chunk.  Used for DMA functions.
 359  */
 360 #ifdef CONFIG_SINGLE_MEMORY_CHUNK
 361 /*
 362  * It makes no sense to consider whether we cross a memory boundary if
 363  * we support just one physical chunk of memory.
 364  */
 365 extern inline int mm_end_of_chunk (unsigned long addr, int len)
 366 {
 367         return 0;
 368 }
 369 #else
 370 int mm_end_of_chunk (unsigned long addr, int len);
 371 #endif
 372
 373 extern void kernel_set_cachemode(void *addr, unsigned long size, int cmode);
 374
 375 /*
 376  * The m68k doesn't have any external MMU info: the kernel page
 377  * tables contain all the necessary information.
 378  */
 379 extern inline void update_mmu_cache(struct vm_area_struct * vma,
 380         unsigned long address, pte_t pte)
 381 {
 382 }
 383
 384 /* Encode and de-code a swap entry (must be !pte_none(e) && !pte_present(e)) */
 385 #define SWP_TYPE(x)                     (((x).val >> 1) & 0xff)
 386 #define SWP_OFFSET(x)                   ((x).val >> 10)
 387 #define SWP_ENTRY(type, offset)         ((swp_entry_t) { ((type) << 1) | ((offset) << 10) })
 388 #define pte_to_swp_entry(pte)           ((swp_entry_t) { pte_val(pte) })
 389 #define swp_entry_to_pte(x)             ((pte_t) { (x).val })
 390
 391 #endif /* __ASSEMBLY__ */
 392
 393 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
 394 #define PageSkip(page)          (0)
 395 #define kern_addr_valid(addr)   (1)
 396
 397 #define io_remap_page_range remap_page_range
 398
 399 #include <asm-generic/pgtable.h>
 400
 401 #endif /* _M68K_PGTABLE_H */