arch/mips/include/asm/pgtable-bits.h

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1994 - 2002 by Ralf Baechle
   7  * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
   8  * Copyright (C) 2002  Maciej W. Rozycki
   9  */
  10 #ifndef _ASM_PGTABLE_BITS_H
  11 #define _ASM_PGTABLE_BITS_H
  12
  13
  14 /*
  15  * Note that we shift the lower 32bits of each EntryLo[01] entry
  16  * 6 bits to the left. That way we can convert the PFN into the
  17  * physical address by a single 'and' operation and gain 6 additional
  18  * bits for storing information which isn't present in a normal
  19  * MIPS page table.
  20  *
  21  * Similar to the Alpha port, we need to keep track of the ref
  22  * and mod bits in software.  We have a software "yeah you can read
  23  * from this page" bit, and a hardware one which actually lets the
  24  * process read from the page.  On the same token we have a software
  25  * writable bit and the real hardware one which actually lets the
  26  * process write to the page, this keeps a mod bit via the hardware
  27  * dirty bit.
  28  *
  29  * Certain revisions of the R4000 and R5000 have a bug where if a
  30  * certain sequence occurs in the last 3 instructions of an executable
  31  * page, and the following page is not mapped, the cpu can do
  32  * unpredictable things.  The code (when it is written) to deal with
  33  * this problem will be in the update_mmu_cache() code for the r4k.
  34  */
  35 #if defined(CONFIG_PHYS_ADDR_T_64BIT) && defined(CONFIG_CPU_MIPS32)
  36
  37 /*
  38  * The following bits are implemented by the TLB hardware
  39  */
  40 #define _PAGE_NO_EXEC_SHIFT     0
  41 #define _PAGE_NO_EXEC           (1 << _PAGE_NO_EXEC_SHIFT)
  42 #define _PAGE_NO_READ_SHIFT     (_PAGE_NO_EXEC_SHIFT + 1)
  43 #define _PAGE_NO_READ           (1 << _PAGE_NO_READ_SHIFT)
  44 #define _PAGE_GLOBAL_SHIFT      (_PAGE_NO_READ_SHIFT + 1)
  45 #define _PAGE_GLOBAL            (1 << _PAGE_GLOBAL_SHIFT)
  46 #define _PAGE_VALID_SHIFT       (_PAGE_GLOBAL_SHIFT + 1)
  47 #define _PAGE_VALID             (1 << _PAGE_VALID_SHIFT)
  48 #define _PAGE_DIRTY_SHIFT       (_PAGE_VALID_SHIFT + 1)
  49 #define _PAGE_DIRTY             (1 << _PAGE_DIRTY_SHIFT)
  50 #define _CACHE_SHIFT            (_PAGE_DIRTY_SHIFT + 1)
  51 #define _CACHE_MASK             (7 << _CACHE_SHIFT)
  52
  53 /*
  54  * The following bits are implemented in software
  55  */
  56 #define _PAGE_PRESENT_SHIFT     (24)
  57 #define _PAGE_PRESENT           (1 << _PAGE_PRESENT_SHIFT)
  58 #define _PAGE_READ_SHIFT        (_PAGE_PRESENT_SHIFT + 1)
  59 #define _PAGE_READ              (1 << _PAGE_READ_SHIFT)
  60 #define _PAGE_WRITE_SHIFT       (_PAGE_READ_SHIFT + 1)
  61 #define _PAGE_WRITE             (1 << _PAGE_WRITE_SHIFT)
  62 #define _PAGE_ACCESSED_SHIFT    (_PAGE_WRITE_SHIFT + 1)
  63 #define _PAGE_ACCESSED          (1 << _PAGE_ACCESSED_SHIFT)
  64 #define _PAGE_MODIFIED_SHIFT    (_PAGE_ACCESSED_SHIFT + 1)
  65 #define _PAGE_MODIFIED          (1 << _PAGE_MODIFIED_SHIFT)
  66
  67 #define _PFN_SHIFT              (PAGE_SHIFT - 12 + _CACHE_SHIFT + 3)
  68
  69 /*
  70  * Bits for extended EntryLo0/EntryLo1 registers
  71  */
  72 #define _PFNX_MASK              0xffffff
  73
  74 #elif defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
  75
  76 /*
  77  * The following bits are implemented in software
  78  */
  79 #define _PAGE_PRESENT_SHIFT     (0)
  80 #define _PAGE_PRESENT           (1 << _PAGE_PRESENT_SHIFT)
  81 #define _PAGE_READ_SHIFT        (_PAGE_PRESENT_SHIFT + 1)
  82 #define _PAGE_READ              (1 << _PAGE_READ_SHIFT)
  83 #define _PAGE_WRITE_SHIFT       (_PAGE_READ_SHIFT + 1)
  84 #define _PAGE_WRITE             (1 << _PAGE_WRITE_SHIFT)
  85 #define _PAGE_ACCESSED_SHIFT    (_PAGE_WRITE_SHIFT + 1)
  86 #define _PAGE_ACCESSED          (1 << _PAGE_ACCESSED_SHIFT)
  87 #define _PAGE_MODIFIED_SHIFT    (_PAGE_ACCESSED_SHIFT + 1)
  88 #define _PAGE_MODIFIED          (1 << _PAGE_MODIFIED_SHIFT)
  89
  90 /*
  91  * The following bits are implemented by the TLB hardware
  92  */
  93 #define _PAGE_GLOBAL_SHIFT      (_PAGE_MODIFIED_SHIFT + 4)
  94 #define _PAGE_GLOBAL            (1 << _PAGE_GLOBAL_SHIFT)
  95 #define _PAGE_VALID_SHIFT       (_PAGE_GLOBAL_SHIFT + 1)
  96 #define _PAGE_VALID             (1 << _PAGE_VALID_SHIFT)
  97 #define _PAGE_DIRTY_SHIFT       (_PAGE_VALID_SHIFT + 1)
  98 #define _PAGE_DIRTY             (1 << _PAGE_DIRTY_SHIFT)
  99 #define _CACHE_UNCACHED_SHIFT   (_PAGE_DIRTY_SHIFT + 1)
 100 #define _CACHE_UNCACHED         (1 << _CACHE_UNCACHED_SHIFT)
 101 #define _CACHE_MASK             _CACHE_UNCACHED
 102
 103 #define _PFN_SHIFT              PAGE_SHIFT
 104
 105 #else
 106 /*
 107  * Below are the "Normal" R4K cases
 108  */
 109
 110 /*
 111  * The following bits are implemented in software
 112  */
 113 #define _PAGE_PRESENT_SHIFT     0
 114 #define _PAGE_PRESENT           (1 << _PAGE_PRESENT_SHIFT)
 115 /* R2 or later cores check for RI/XI support to determine _PAGE_READ */
 116 #if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6)
 117 #define _PAGE_WRITE_SHIFT       (_PAGE_PRESENT_SHIFT + 1)
 118 #define _PAGE_WRITE             (1 << _PAGE_WRITE_SHIFT)
 119 #else
 120 #define _PAGE_READ_SHIFT        (_PAGE_PRESENT_SHIFT + 1)
 121 #define _PAGE_READ              (1 << _PAGE_READ_SHIFT)
 122 #define _PAGE_WRITE_SHIFT       (_PAGE_READ_SHIFT + 1)
 123 #define _PAGE_WRITE             (1 << _PAGE_WRITE_SHIFT)
 124 #endif
 125 #define _PAGE_ACCESSED_SHIFT    (_PAGE_WRITE_SHIFT + 1)
 126 #define _PAGE_ACCESSED          (1 << _PAGE_ACCESSED_SHIFT)
 127 #define _PAGE_MODIFIED_SHIFT    (_PAGE_ACCESSED_SHIFT + 1)
 128 #define _PAGE_MODIFIED          (1 << _PAGE_MODIFIED_SHIFT)
 129
 130 #if defined(CONFIG_64BIT) && defined(CONFIG_MIPS_HUGE_TLB_SUPPORT)
 131 /* Huge TLB page */
 132 #define _PAGE_HUGE_SHIFT        (_PAGE_MODIFIED_SHIFT + 1)
 133 #define _PAGE_HUGE              (1 << _PAGE_HUGE_SHIFT)
 134 #endif  /* CONFIG_64BIT && CONFIG_MIPS_HUGE_TLB_SUPPORT */
 135
 136 #if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6)
 137 /* XI - page cannot be executed */
 138 #ifdef _PAGE_HUGE_SHIFT
 139 #define _PAGE_NO_EXEC_SHIFT     (_PAGE_HUGE_SHIFT + 1)
 140 #else
 141 #define _PAGE_NO_EXEC_SHIFT     (_PAGE_MODIFIED_SHIFT + 1)
 142 #endif
 143 #define _PAGE_NO_EXEC           (cpu_has_rixi ? (1 << _PAGE_NO_EXEC_SHIFT) : 0)
 144
 145 /* RI - page cannot be read */
 146 #define _PAGE_READ_SHIFT        (_PAGE_NO_EXEC_SHIFT + 1)
 147 #define _PAGE_READ              (cpu_has_rixi ? 0 : (1 << _PAGE_READ_SHIFT))
 148 #define _PAGE_NO_READ_SHIFT     _PAGE_READ_SHIFT
 149 #define _PAGE_NO_READ           (cpu_has_rixi ? (1 << _PAGE_READ_SHIFT) : 0)
 150 #endif  /* defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6) */
 151
 152 #if defined(_PAGE_NO_READ_SHIFT)
 153 #define _PAGE_GLOBAL_SHIFT      (_PAGE_NO_READ_SHIFT + 1)
 154 #elif defined(_PAGE_HUGE_SHIFT)
 155 #define _PAGE_GLOBAL_SHIFT      (_PAGE_HUGE_SHIFT + 1)
 156 #else
 157 #define _PAGE_GLOBAL_SHIFT      (_PAGE_MODIFIED_SHIFT + 1)
 158 #endif
 159 #define _PAGE_GLOBAL            (1 << _PAGE_GLOBAL_SHIFT)
 160
 161 #define _PAGE_VALID_SHIFT       (_PAGE_GLOBAL_SHIFT + 1)
 162 #define _PAGE_VALID             (1 << _PAGE_VALID_SHIFT)
 163 #define _PAGE_DIRTY_SHIFT       (_PAGE_VALID_SHIFT + 1)
 164 #define _PAGE_DIRTY             (1 << _PAGE_DIRTY_SHIFT)
 165 #define _CACHE_SHIFT            (_PAGE_DIRTY_SHIFT + 1)
 166 #define _CACHE_MASK             (7 << _CACHE_SHIFT)
 167
 168 #define _PFN_SHIFT              (PAGE_SHIFT - 12 + _CACHE_SHIFT + 3)
 169
 170 #endif /* defined(CONFIG_PHYS_ADDR_T_64BIT && defined(CONFIG_CPU_MIPS32) */
 171
 172 #ifndef _PAGE_NO_EXEC
 173 #define _PAGE_NO_EXEC           0
 174 #endif
 175 #ifndef _PAGE_NO_READ
 176 #define _PAGE_NO_READ           0
 177 #endif
 178
 179 #define _PAGE_SILENT_READ       _PAGE_VALID
 180 #define _PAGE_SILENT_WRITE      _PAGE_DIRTY
 181
 182 #define _PFN_MASK               (~((1 << (_PFN_SHIFT)) - 1))
 183
 184 /*
 185  * The final layouts of the PTE bits are:
 186  *
 187  *   64-bit, R1 or earlier:     CCC D V G [S H] M A W R P
 188  *   32-bit, R1 or earler:      CCC D V G M A W R P
 189  *   64-bit, R2 or later:       CCC D V G RI/R XI [S H] M A W P
 190  *   32-bit, R2 or later:       CCC D V G RI/R XI M A W P
 191  */
 192
 193
 194 #ifndef __ASSEMBLY__
 195 /*
 196  * pte_to_entrylo converts a page table entry (PTE) into a Mips
 197  * entrylo0/1 value.
 198  */
 199 static inline uint64_t pte_to_entrylo(unsigned long pte_val)
 200 {
 201 #if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_CPU_MIPSR6)
 202         if (cpu_has_rixi) {
 203                 int sa;
 204 #ifdef CONFIG_32BIT
 205                 sa = 31 - _PAGE_NO_READ_SHIFT;
 206 #else
 207                 sa = 63 - _PAGE_NO_READ_SHIFT;
 208 #endif
 209                 /*
 210                  * C has no way to express that this is a DSRL
 211                  * _PAGE_NO_EXEC_SHIFT followed by a ROTR 2.  Luckily
 212                  * in the fast path this is done in assembly
 213                  */
 214                 return (pte_val >> _PAGE_GLOBAL_SHIFT) |
 215                         ((pte_val & (_PAGE_NO_EXEC | _PAGE_NO_READ)) << sa);
 216         }
 217 #endif
 218
 219         return pte_val >> _PAGE_GLOBAL_SHIFT;
 220 }
 221 #endif
 222
 223 /*
 224  * Cache attributes
 225  */
 226 #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
 227
 228 #define _CACHE_CACHABLE_NONCOHERENT 0
 229 #define _CACHE_UNCACHED_ACCELERATED _CACHE_UNCACHED
 230
 231 #elif defined(CONFIG_CPU_SB1)
 232
 233 /* No penalty for being coherent on the SB1, so just
 234    use it for "noncoherent" spaces, too.  Shouldn't hurt. */
 235
 236 #define _CACHE_CACHABLE_NONCOHERENT (5<<_CACHE_SHIFT)
 237
 238 #elif defined(CONFIG_CPU_LOONGSON3)
 239
 240 /* Using COHERENT flag for NONCOHERENT doesn't hurt. */
 241
 242 #define _CACHE_CACHABLE_NONCOHERENT (3<<_CACHE_SHIFT)  /* LOONGSON       */
 243 #define _CACHE_CACHABLE_COHERENT    (3<<_CACHE_SHIFT)  /* LOONGSON-3     */
 244
 245 #elif defined(CONFIG_MACH_INGENIC)
 246
 247 /* Ingenic uses the WA bit to achieve write-combine memory writes */
 248 #define _CACHE_UNCACHED_ACCELERATED (1<<_CACHE_SHIFT)
 249
 250 #endif
 251
 252 #ifndef _CACHE_CACHABLE_NO_WA
 253 #define _CACHE_CACHABLE_NO_WA           (0<<_CACHE_SHIFT)
 254 #endif
 255 #ifndef _CACHE_CACHABLE_WA
 256 #define _CACHE_CACHABLE_WA              (1<<_CACHE_SHIFT)
 257 #endif
 258 #ifndef _CACHE_UNCACHED
 259 #define _CACHE_UNCACHED                 (2<<_CACHE_SHIFT)
 260 #endif
 261 #ifndef _CACHE_CACHABLE_NONCOHERENT
 262 #define _CACHE_CACHABLE_NONCOHERENT     (3<<_CACHE_SHIFT)
 263 #endif
 264 #ifndef _CACHE_CACHABLE_CE
 265 #define _CACHE_CACHABLE_CE              (4<<_CACHE_SHIFT)
 266 #endif
 267 #ifndef _CACHE_CACHABLE_COW
 268 #define _CACHE_CACHABLE_COW             (5<<_CACHE_SHIFT)
 269 #endif
 270 #ifndef _CACHE_CACHABLE_CUW
 271 #define _CACHE_CACHABLE_CUW             (6<<_CACHE_SHIFT)
 272 #endif
 273 #ifndef _CACHE_UNCACHED_ACCELERATED
 274 #define _CACHE_UNCACHED_ACCELERATED     (7<<_CACHE_SHIFT)
 275 #endif
 276
 277 #define __READABLE      (_PAGE_SILENT_READ | _PAGE_READ | _PAGE_ACCESSED)
 278 #define __WRITEABLE     (_PAGE_SILENT_WRITE | _PAGE_WRITE | _PAGE_MODIFIED)
 279
 280 #define _PAGE_CHG_MASK  (_PAGE_ACCESSED | _PAGE_MODIFIED |      \
 281                          _PFN_MASK | _CACHE_MASK)
 282
 283 #endif /* _ASM_PGTABLE_BITS_H */