kernel/arch/amd64/include/mm/page.h

   1 /*
   2  * Copyright (C) 2005 Ondrej Palkovsky
   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 amd64mm
  30  * @{
  31  */
  32 /** @file
  33  */
  34
  35 /** Paging on AMD64
  36  *
  37  * The space is divided in positive numbers - userspace and
  38  * negative numbers - kernel space. The 'negative' space starting
  39  * with 0xffff800000000000 and ending with 0xffffffff80000000
  40  * (-2GB) is identically mapped physical memory. The area
  41  * (0xffffffff80000000 ... 0xffffffffffffffff is again identically
  42  * mapped first 2GB.
  43  *
  44  * ATTENTION - PA2KA(KA2PA(x)) != x if 'x' is in kernel
  45  */
  46
  47 #ifndef KERN_amd64_PAGE_H_
  48 #define KERN_amd64_PAGE_H_
  49
  50 #include <arch/mm/frame.h>
  51
  52 #define PAGE_WIDTH      FRAME_WIDTH
  53 #define PAGE_SIZE       FRAME_SIZE
  54
  55 #define PAGE_COLOR_BITS 0                       /* dummy */
  56
  57 #ifdef KERNEL
  58
  59 #ifndef __ASM__
  60 #  include <mm/page.h>
  61 #  include <arch/types.h>
  62 #endif
  63
  64 #ifndef __ASM__
  65 static inline uintptr_t ka2pa(uintptr_t x)
  66 {
  67         if (x > 0xffffffff80000000)
  68                 return x - 0xffffffff80000000;
  69         else
  70                 return x - 0xffff800000000000;
  71 }
  72 # define KA2PA(x)      ka2pa((uintptr_t)x)
  73 # define PA2KA_CODE(x)      (((uintptr_t) (x)) + 0xffffffff80000000)
  74 # define PA2KA(x)      (((uintptr_t) (x)) + 0xffff800000000000)
  75 #else
  76 # define KA2PA(x)      ((x) - 0xffffffff80000000)
  77 # define PA2KA(x)      ((x) + 0xffffffff80000000)
  78 #endif
  79
  80 #define PTL0_ENTRIES_ARCH       512
  81 #define PTL1_ENTRIES_ARCH       512
  82 #define PTL2_ENTRIES_ARCH       512
  83 #define PTL3_ENTRIES_ARCH       512
  84
  85 #define PTL0_INDEX_ARCH(vaddr)  (((vaddr)>>39)&0x1ff)
  86 #define PTL1_INDEX_ARCH(vaddr)  (((vaddr)>>30)&0x1ff)
  87 #define PTL2_INDEX_ARCH(vaddr)  (((vaddr)>>21)&0x1ff)
  88 #define PTL3_INDEX_ARCH(vaddr)  (((vaddr)>>12)&0x1ff)
  89
  90 #define GET_PTL1_ADDRESS_ARCH(ptl0, i)          ((pte_t *) ((((uint64_t) ((pte_t *)(ptl0))[(i)].addr_12_31)<<12) | (((uint64_t) ((pte_t *)(ptl0))[(i)].addr_32_51)<<32 )))
  91 #define GET_PTL2_ADDRESS_ARCH(ptl1, i)          ((pte_t *) ((((uint64_t) ((pte_t *)(ptl1))[(i)].addr_12_31)<<12) | (((uint64_t) ((pte_t *)(ptl1))[(i)].addr_32_51)<<32 )))
  92 #define GET_PTL3_ADDRESS_ARCH(ptl2, i)          ((pte_t *) ((((uint64_t) ((pte_t *)(ptl2))[(i)].addr_12_31)<<12) | (((uint64_t) ((pte_t *)(ptl2))[(i)].addr_32_51)<<32 )))
  93 #define GET_FRAME_ADDRESS_ARCH(ptl3, i)         ((uintptr_t *) ((((uint64_t) ((pte_t *)(ptl3))[(i)].addr_12_31)<<12) | (((uint64_t) ((pte_t *)(ptl3))[(i)].addr_32_51)<<32 )))
  94
  95 #define SET_PTL0_ADDRESS_ARCH(ptl0)             (write_cr3((uintptr_t) (ptl0)))
  96 #define SET_PTL1_ADDRESS_ARCH(ptl0, i, a)       set_pt_addr((pte_t *)(ptl0), (index_t)(i), a)
  97 #define SET_PTL2_ADDRESS_ARCH(ptl1, i, a)       set_pt_addr((pte_t *)(ptl1), (index_t)(i), a)
  98 #define SET_PTL3_ADDRESS_ARCH(ptl2, i, a)       set_pt_addr((pte_t *)(ptl2), (index_t)(i), a)
  99 #define SET_FRAME_ADDRESS_ARCH(ptl3, i, a)      set_pt_addr((pte_t *)(ptl3), (index_t)(i), a)
 100
 101 #define GET_PTL1_FLAGS_ARCH(ptl0, i)            get_pt_flags((pte_t *)(ptl0), (index_t)(i))
 102 #define GET_PTL2_FLAGS_ARCH(ptl1, i)            get_pt_flags((pte_t *)(ptl1), (index_t)(i))
 103 #define GET_PTL3_FLAGS_ARCH(ptl2, i)            get_pt_flags((pte_t *)(ptl2), (index_t)(i))
 104 #define GET_FRAME_FLAGS_ARCH(ptl3, i)           get_pt_flags((pte_t *)(ptl3), (index_t)(i))
 105
 106 #define SET_PTL1_FLAGS_ARCH(ptl0, i, x)         set_pt_flags((pte_t *)(ptl0), (index_t)(i), (x))
 107 #define SET_PTL2_FLAGS_ARCH(ptl1, i, x)         set_pt_flags((pte_t *)(ptl1), (index_t)(i), (x))
 108 #define SET_PTL3_FLAGS_ARCH(ptl2, i, x)         set_pt_flags((pte_t *)(ptl2), (index_t)(i), (x))
 109 #define SET_FRAME_FLAGS_ARCH(ptl3, i, x)        set_pt_flags((pte_t *)(ptl3), (index_t)(i), (x))
 110
 111 #define PTE_VALID_ARCH(p)                       (*((uint64_t *) (p)) != 0)
 112 #define PTE_PRESENT_ARCH(p)                     ((p)->present != 0)
 113 #define PTE_GET_FRAME_ARCH(p)                   ((((uintptr_t)(p)->addr_12_31)<<12) | ((uintptr_t)(p)->addr_32_51<<32))
 114 #define PTE_WRITABLE_ARCH(p)                    ((p)->writeable != 0)
 115 #define PTE_EXECUTABLE_ARCH(p)                  ((p)->no_execute == 0)
 116
 117 #ifndef __ASM__
 118
 119 /* Page fault error codes. */
 120
 121 /** When bit on this position is 0, the page fault was caused by a not-present page. */
 122 #define PFERR_CODE_P            (1<<0)
 123
 124 /** When bit on this position is 1, the page fault was caused by a write. */
 125 #define PFERR_CODE_RW           (1<<1)
 126
 127 /** When bit on this position is 1, the page fault was caused in user mode. */
 128 #define PFERR_CODE_US           (1<<2)
 129
 130 /** When bit on this position is 1, a reserved bit was set in page directory. */
 131 #define PFERR_CODE_RSVD         (1<<3)
 132
 133 /** When bit on this position os 1, the page fault was caused during instruction fecth. */
 134 #define PFERR_CODE_ID           (1<<4)
 135
 136 /** Page Table Entry. */
 137 struct page_specifier {
 138         unsigned present : 1;
 139         unsigned writeable : 1;
 140         unsigned uaccessible : 1;
 141         unsigned page_write_through : 1;
 142         unsigned page_cache_disable : 1;
 143         unsigned accessed : 1;
 144         unsigned dirty : 1;
 145         unsigned unused: 1;
 146         unsigned global : 1;
 147         unsigned soft_valid : 1;                /**< Valid content even if present bit is cleared. */
 148         unsigned avl : 2;
 149         unsigned addr_12_31 : 30;
 150         unsigned addr_32_51 : 21;
 151         unsigned no_execute : 1;
 152 } __attribute__ ((packed));
 153
 154 static inline int get_pt_flags(pte_t *pt, index_t i)
 155 {
 156         pte_t *p = &pt[i];
 157
 158         return (
 159                 (!p->page_cache_disable)<<PAGE_CACHEABLE_SHIFT |
 160                 (!p->present)<<PAGE_PRESENT_SHIFT |
 161                 p->uaccessible<<PAGE_USER_SHIFT |
 162                 1<<PAGE_READ_SHIFT |
 163                 p->writeable<<PAGE_WRITE_SHIFT |
 164                 (!p->no_execute)<<PAGE_EXEC_SHIFT |
 165                 p->global<<PAGE_GLOBAL_SHIFT
 166         );
 167 }
 168
 169 static inline void set_pt_addr(pte_t *pt, index_t i, uintptr_t a)
 170 {
 171         pte_t *p = &pt[i];
 172
 173         p->addr_12_31 = (a >> 12) & 0xfffff;
 174         p->addr_32_51 = a >> 32;
 175 }
 176
 177 static inline void set_pt_flags(pte_t *pt, index_t i, int flags)
 178 {
 179         pte_t *p = &pt[i];
 180
 181         p->page_cache_disable = !(flags & PAGE_CACHEABLE);
 182         p->present = !(flags & PAGE_NOT_PRESENT);
 183         p->uaccessible = (flags & PAGE_USER) != 0;
 184         p->writeable = (flags & PAGE_WRITE) != 0;
 185         p->no_execute = (flags & PAGE_EXEC) == 0;
 186         p->global = (flags & PAGE_GLOBAL) != 0;
 187
 188         /*
 189          * Ensure that there is at least one bit set even if the present bit is cleared.
 190          */
 191         p->soft_valid = 1;
 192 }
 193
 194 extern void page_arch_init(void);
 195 extern void page_fault(int n, istate_t *istate);
 196
 197 #endif /* __ASM__ */
 198
 199 #endif /* KERNEL */
 200
 201 #endif
 202
 203 /** @}
 204  */