include/asm-mips/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_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
  36
  37 #define _PAGE_PRESENT               (1<<6)  /* implemented in software */
  38 #define _PAGE_READ                  (1<<7)  /* implemented in software */
  39 #define _PAGE_WRITE                 (1<<8)  /* implemented in software */
  40 #define _PAGE_ACCESSED              (1<<9)  /* implemented in software */
  41 #define _PAGE_MODIFIED              (1<<10) /* implemented in software */
  42 #define _PAGE_FILE                  (1<<10) /* set:pagecache unset:swap */
  43
  44 #define _PAGE_R4KBUG                (1<<0)  /* workaround for r4k bug  */
  45 #define _PAGE_GLOBAL                (1<<0)
  46 #define _PAGE_VALID                 (1<<1)
  47 #define _PAGE_SILENT_READ           (1<<1)  /* synonym                 */
  48 #define _PAGE_DIRTY                 (1<<2)  /* The MIPS dirty bit      */
  49 #define _PAGE_SILENT_WRITE          (1<<2)
  50 #define _CACHE_SHIFT                3
  51 #define _CACHE_MASK                 (7<<3)
  52
  53 #else
  54
  55 #define _PAGE_PRESENT               (1<<0)  /* implemented in software */
  56 #define _PAGE_READ                  (1<<1)  /* implemented in software */
  57 #define _PAGE_WRITE                 (1<<2)  /* implemented in software */
  58 #define _PAGE_ACCESSED              (1<<3)  /* implemented in software */
  59 #define _PAGE_MODIFIED              (1<<4)  /* implemented in software */
  60 #define _PAGE_FILE                  (1<<4)  /* set:pagecache unset:swap */
  61
  62 #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
  63
  64 #define _PAGE_GLOBAL                (1<<8)
  65 #define _PAGE_VALID                 (1<<9)
  66 #define _PAGE_SILENT_READ           (1<<9)  /* synonym                 */
  67 #define _PAGE_DIRTY                 (1<<10) /* The MIPS dirty bit      */
  68 #define _PAGE_SILENT_WRITE          (1<<10)
  69 #define _CACHE_UNCACHED             (1<<11)
  70 #define _CACHE_MASK                 (1<<11)
  71
  72 #else
  73
  74 #define _PAGE_R4KBUG                (1<<5)  /* workaround for r4k bug  */
  75 #define _PAGE_GLOBAL                (1<<6)
  76 #define _PAGE_VALID                 (1<<7)
  77 #define _PAGE_SILENT_READ           (1<<7)  /* synonym                 */
  78 #define _PAGE_DIRTY                 (1<<8)  /* The MIPS dirty bit      */
  79 #define _PAGE_SILENT_WRITE          (1<<8)
  80 #define _CACHE_SHIFT                9
  81 #define _CACHE_MASK                 (7<<9)
  82
  83 #endif
  84 #endif /* defined(CONFIG_64BIT_PHYS_ADDR && defined(CONFIG_CPU_MIPS32) */
  85
  86
  87 /*
  88  * Cache attributes
  89  */
  90 #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
  91
  92 #define _CACHE_CACHABLE_NONCOHERENT 0
  93
  94 #elif defined(CONFIG_CPU_SB1)
  95
  96 /* No penalty for being coherent on the SB1, so just
  97    use it for "noncoherent" spaces, too.  Shouldn't hurt. */
  98
  99 #define _CACHE_UNCACHED             (2<<_CACHE_SHIFT)
 100 #define _CACHE_CACHABLE_COW         (5<<_CACHE_SHIFT)
 101 #define _CACHE_CACHABLE_NONCOHERENT (5<<_CACHE_SHIFT)
 102 #define _CACHE_UNCACHED_ACCELERATED (7<<_CACHE_SHIFT)
 103
 104 #elif defined(CONFIG_CPU_RM9000)
 105
 106 #define _CACHE_WT                   (0<<_CACHE_SHIFT)
 107 #define _CACHE_WTWA                 (1<<_CACHE_SHIFT)
 108 #define _CACHE_UC_B                 (2<<_CACHE_SHIFT)
 109 #define _CACHE_WB                   (3<<_CACHE_SHIFT)
 110 #define _CACHE_CWBEA                (4<<_CACHE_SHIFT)
 111 #define _CACHE_CWB                  (5<<_CACHE_SHIFT)
 112 #define _CACHE_UCNB                 (6<<_CACHE_SHIFT)
 113 #define _CACHE_FPC                  (7<<_CACHE_SHIFT)
 114
 115 #define _CACHE_UNCACHED             _CACHE_UC_B
 116 #define _CACHE_CACHABLE_NONCOHERENT _CACHE_WB
 117
 118 #else
 119
 120 #define _CACHE_CACHABLE_NO_WA       (0<<_CACHE_SHIFT)  /* R4600 only      */
 121 #define _CACHE_CACHABLE_WA          (1<<_CACHE_SHIFT)  /* R4600 only      */
 122 #define _CACHE_UNCACHED             (2<<_CACHE_SHIFT)  /* R4[0246]00      */
 123 #define _CACHE_CACHABLE_NONCOHERENT (3<<_CACHE_SHIFT)  /* R4[0246]00      */
 124 #define _CACHE_CACHABLE_CE          (4<<_CACHE_SHIFT)  /* R4[04]00MC only */
 125 #define _CACHE_CACHABLE_COW         (5<<_CACHE_SHIFT)  /* R4[04]00MC only */
 126 #define _CACHE_CACHABLE_COHERENT    (5<<_CACHE_SHIFT)  /* MIPS32R2 CMP    */
 127 #define _CACHE_CACHABLE_CUW         (6<<_CACHE_SHIFT)  /* R4[04]00MC only */
 128 #define _CACHE_UNCACHED_ACCELERATED (7<<_CACHE_SHIFT)  /* R10000 only     */
 129
 130 #endif
 131
 132 #define __READABLE      (_PAGE_READ | _PAGE_SILENT_READ | _PAGE_ACCESSED)
 133 #define __WRITEABLE     (_PAGE_WRITE | _PAGE_SILENT_WRITE | _PAGE_MODIFIED)
 134
 135 #define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_ACCESSED | _PAGE_MODIFIED | _CACHE_MASK)
 136
 137 #endif /* _ASM_PGTABLE_BITS_H */