1 | /* |
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2 | * page.h - physical page descriptor and related operations |
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3 | * |
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4 | * Authors Ghassan Almalles (2008,2009,2010,2011,2012) |
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5 | * Alain Greiner (2016) |
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6 | * |
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7 | * Copyright (c) UPMC Sorbonne Universites |
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8 | * |
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9 | * This file is part of ALMOS-MKH. |
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10 | * |
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11 | * ALMOS-MKH is free software; you can redistribute it and/or modify it |
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12 | * under the terms of the GNU General Public License as published by |
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13 | * the Free Software Foundation; version 2.0 of the License. |
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14 | * |
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15 | * ALMOS-MKH is distributed in the hope that it will be useful, but |
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16 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
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17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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18 | * General Public License for more details. |
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19 | * |
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20 | * You should have received a copy of the GNU General Public License |
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21 | * along with ALMOS-MKH; if not, write to the Free Software Foundation, |
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22 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
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23 | */ |
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24 | |
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25 | #ifndef _PAGE_H_ |
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26 | #define _PAGE_H_ |
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27 | |
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28 | #include <kernel_config.h> |
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29 | #include <hal_kernel_types.h> |
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30 | #include <remote_busylock.h> |
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31 | #include <list.h> |
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32 | |
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33 | /*** Forward declarations ***/ |
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34 | |
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35 | struct mapper_s; |
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36 | |
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37 | /************************************************************************************* |
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38 | * This defines the flags that can be attached to a physical page. |
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39 | ************************************************************************************/ |
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40 | |
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41 | #define PG_INIT 0x0001 // page descriptor has been initialised |
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42 | #define PG_RESERVED 0x0002 // cannot be allocated by PPM |
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43 | #define PG_FREE 0x0004 // page not yet allocated by PPM |
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44 | #define PG_DIRTY 0x0040 // page has been written |
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45 | #define PG_COW 0x0080 // page is copy-on-write |
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46 | |
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47 | /************************************************************************************* |
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48 | * This structure defines a physical page descriptor. |
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49 | * - The remote_busylock is used to allows any remote thread to atomically |
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50 | * test/modify the forks counter or the page flags. |
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51 | * - The list entry is used to register the page in a free list or in dirty list. |
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52 | * NOTE: Size is 48 bytes for a 32 bits core. |
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53 | * TODO : the refcount use is not defined [AG] |
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54 | ************************************************************************************/ |
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55 | |
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56 | typedef struct page_s |
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57 | { |
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58 | uint32_t flags; /*! flags defined above (4) */ |
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59 | uint32_t order; /*! log2( number of small pages) (4) */ |
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60 | struct mapper_s * mapper; /*! local pointer on associated mapper (4) */ |
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61 | uint32_t index; /*! page index in mapper (4) */ |
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62 | list_entry_t list; /*! for both dirty pages and free pages (8) */ |
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63 | uint32_t refcount; /*! reference counter TODO ??? [AG] (4) */ |
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64 | uint32_t forks; /*! number of pending forks (4) */ |
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65 | remote_busylock_t lock; /*! protect forks or flags modifs (16) */ |
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66 | } |
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67 | page_t; |
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68 | |
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69 | /************************************************************************************* |
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70 | * This function initializes one page descriptor. |
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71 | ************************************************************************************* |
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72 | * @ page : pointer to page descriptor |
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73 | ************************************************************************************/ |
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74 | inline void page_init( page_t * page ); |
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75 | |
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76 | /************************************************************************************* |
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77 | * This function atomically set one or several flags in page descriptor flags. |
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78 | ************************************************************************************* |
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79 | * @ page : pointer to page descriptor. |
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80 | * @ value : all non zero bits in value will be set. |
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81 | ************************************************************************************/ |
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82 | inline void page_set_flag( page_t * page, |
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83 | uint32_t value ); |
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84 | |
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85 | /************************************************************************************* |
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86 | * This function atomically reset one or several flags in page descriptor flags. |
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87 | ************************************************************************************* |
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88 | * @ page : pointer to page descriptor. |
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89 | * @ value : all non zero bits in value will be cleared. |
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90 | ************************************************************************************/ |
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91 | inline void page_clear_flag( page_t * page, |
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92 | uint32_t value ); |
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93 | |
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94 | /************************************************************************************* |
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95 | * This function tests the value of one or several flags in page descriptor flags. |
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96 | ************************************************************************************* |
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97 | * @ page : pointer to page descriptor. |
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98 | * @ value : all non zero bits will be tested. |
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99 | * @ returns true if at least one non zero bit in value is set / false otherwise. |
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100 | ************************************************************************************/ |
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101 | inline bool_t page_is_flag( page_t * page, |
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102 | uint32_t value ); |
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103 | |
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104 | /************************************************************************************* |
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105 | * This function resets to 0 all bytes in a given page. |
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106 | ************************************************************************************* |
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107 | * @ page : pointer on page descriptor. |
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108 | ************************************************************************************/ |
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109 | void page_zero( page_t * page ); |
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110 | |
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111 | /************************************************************************************* |
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112 | * This blocking function atomically increments the page refcount. |
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113 | ************************************************************************************* |
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114 | * @ page : pointer on page descriptor. |
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115 | ************************************************************************************/ |
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116 | inline void page_refcount_up( page_t * page ); |
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117 | |
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118 | /************************************************************************************* |
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119 | * This blocking function atomically decrements the page refcount. |
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120 | ************************************************************************************* |
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121 | * @ page : pointer on page descriptor. |
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122 | ************************************************************************************/ |
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123 | inline void page_refcount_down( page_t * page ); |
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124 | |
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125 | /************************************************************************************* |
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126 | * This function display the values contained in a page descriptor. |
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127 | ************************************************************************************* |
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128 | * @ page : pointer on page descriptor. |
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129 | ************************************************************************************/ |
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130 | void page_print( page_t * page ); |
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131 | |
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132 | |
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133 | #endif /* _PAGE_H_ */ |
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