kernel/arch/mips32/include/mm/page.h

   1 /*
   2  * Copyright (c) 2003-2004 Jakub Jermar
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * - Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * - The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /** @addtogroup mips32mm
  30  * @{
  31  */
  32 /** @file
  33  */
  34
  35 #ifndef KERN_mips32_PAGE_H_
  36 #define KERN_mips32_PAGE_H_
  37
  38 #include <arch/mm/frame.h>
  39
  40 #define PAGE_WIDTH      FRAME_WIDTH
  41 #define PAGE_SIZE       FRAME_SIZE
  42
  43 #define PAGE_COLOR_BITS 0                       /* dummy */
  44
  45 #ifndef __ASM__
  46 #  define KA2PA(x)      (((uintptr_t) (x)) - 0x80000000)
  47 #  define PA2KA(x)      (((uintptr_t) (x)) + 0x80000000)
  48 #else
  49 #  define KA2PA(x)      ((x) - 0x80000000)
  50 #  define PA2KA(x)      ((x) + 0x80000000)
  51 #endif
  52
  53 #ifdef KERNEL
  54
  55 /*
  56  * Implementation of generic 4-level page table interface.
  57  *
  58  * Page table layout:
  59  * - 32-bit virtual addresses
  60  * - Offset is 14 bits => pages are 16K long
  61  * - PTE's use similar format as CP0 EntryLo[01] registers => PTE is therefore 4 bytes long
  62  * - PTE's replace EntryLo v (valid) bit with p (present) bit
  63  * - PTE's use only one bit to distinguish between cacheable and uncacheable mappings
  64  * - PTE's define soft_valid field to ensure there is at least one 1 bit even if the p bit is cleared
  65  * - PTE's make use of CP0 EntryLo's two-bit reserved field for bit W (writable) and bit A (accessed)
  66  * - PTL0 has 64 entries (6 bits)
  67  * - PTL1 is not used
  68  * - PTL2 is not used
  69  * - PTL3 has 4096 entries (12 bits)
  70  */
  71
  72 #define PTL0_ENTRIES_ARCH       64
  73 #define PTL1_ENTRIES_ARCH       0
  74 #define PTL2_ENTRIES_ARCH       0
  75 #define PTL3_ENTRIES_ARCH       4096
  76
  77 #define PTL0_INDEX_ARCH(vaddr)  ((vaddr)>>26)
  78 #define PTL1_INDEX_ARCH(vaddr)  0
  79 #define PTL2_INDEX_ARCH(vaddr)  0
  80 #define PTL3_INDEX_ARCH(vaddr)  (((vaddr)>>14) & 0xfff)
  81
  82 #define SET_PTL0_ADDRESS_ARCH(ptl0)
  83
  84 #define GET_PTL1_ADDRESS_ARCH(ptl0, i)          (((pte_t *)(ptl0))[(i)].pfn<<12)
  85 #define GET_PTL2_ADDRESS_ARCH(ptl1, i)          (ptl1)
  86 #define GET_PTL3_ADDRESS_ARCH(ptl2, i)          (ptl2)
  87 #define GET_FRAME_ADDRESS_ARCH(ptl3, i)         (((pte_t *)(ptl3))[(i)].pfn<<12)
  88
  89 #define SET_PTL1_ADDRESS_ARCH(ptl0, i, a)       (((pte_t *)(ptl0))[(i)].pfn = (a)>>12)
  90 #define SET_PTL2_ADDRESS_ARCH(ptl1, i, a)
  91 #define SET_PTL3_ADDRESS_ARCH(ptl2, i, a)
  92 #define SET_FRAME_ADDRESS_ARCH(ptl3, i, a)      (((pte_t *)(ptl3))[(i)].pfn = (a)>>12)
  93
  94 #define GET_PTL1_FLAGS_ARCH(ptl0, i)            get_pt_flags((pte_t *)(ptl0), (index_t)(i))
  95 #define GET_PTL2_FLAGS_ARCH(ptl1, i)            PAGE_PRESENT
  96 #define GET_PTL3_FLAGS_ARCH(ptl2, i)            PAGE_PRESENT
  97 #define GET_FRAME_FLAGS_ARCH(ptl3, i)           get_pt_flags((pte_t *)(ptl3), (index_t)(i))
  98
  99 #define SET_PTL1_FLAGS_ARCH(ptl0, i, x)         set_pt_flags((pte_t *)(ptl0), (index_t)(i), (x))
 100 #define SET_PTL2_FLAGS_ARCH(ptl1, i, x)
 101 #define SET_PTL3_FLAGS_ARCH(ptl2, i, x)
 102 #define SET_FRAME_FLAGS_ARCH(ptl3, i, x)        set_pt_flags((pte_t *)(ptl3), (index_t)(i), (x))
 103
 104 #define PTE_VALID_ARCH(pte)                     (*((uint32_t *) (pte)) != 0)
 105 #define PTE_PRESENT_ARCH(pte)                   ((pte)->p != 0)
 106 #define PTE_GET_FRAME_ARCH(pte)                 ((pte)->pfn<<12)
 107 #define PTE_WRITABLE_ARCH(pte)                  ((pte)->w != 0)
 108 #define PTE_EXECUTABLE_ARCH(pte)                1
 109
 110 #ifndef __ASM__
 111
 112 #include <arch/mm/tlb.h>
 113 #include <mm/page.h>
 114 #include <arch/mm/frame.h>
 115 #include <arch/types.h>
 116
 117 static inline int get_pt_flags(pte_t *pt, index_t i)
 118 {
 119         pte_t *p = &pt[i];
 120
 121         return (
 122                 (p->cacheable<<PAGE_CACHEABLE_SHIFT) |
 123                 ((!p->p)<<PAGE_PRESENT_SHIFT) |
 124                 (1<<PAGE_USER_SHIFT) |
 125                 (1<<PAGE_READ_SHIFT) |
 126                 ((p->w)<<PAGE_WRITE_SHIFT) |
 127                 (1<<PAGE_EXEC_SHIFT) |
 128                 (p->g<<PAGE_GLOBAL_SHIFT)
 129         );
 130
 131 }
 132
 133 static inline void set_pt_flags(pte_t *pt, index_t i, int flags)
 134 {
 135         pte_t *p = &pt[i];
 136
 137         p->cacheable = (flags & PAGE_CACHEABLE) != 0;
 138         p->p = !(flags & PAGE_NOT_PRESENT);
 139         p->g = (flags & PAGE_GLOBAL) != 0;
 140         p->w = (flags & PAGE_WRITE) != 0;
 141
 142         /*
 143          * Ensure that valid entries have at least one bit set.
 144          */
 145         p->soft_valid = 1;
 146 }
 147
 148 extern void page_arch_init(void);
 149
 150 #endif /* __ASM__ */
 151
 152 #endif /* KERNEL */
 153
 154 #endif
 155
 156 /** @}
 157  */