1 | /* |
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2 | * mapper.h - Kernel cache for VFS files/directories definition. |
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3 | * |
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4 | * Authors Mohamed Lamine Karaoui (2015) |
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5 | * Alain Greiner (2016,2017,2018,2019) |
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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 _MAPPER_H_ |
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26 | #define _MAPPER_H_ |
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27 | |
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28 | #include <hal_kernel_types.h> |
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29 | #include <hal_atomic.h> |
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30 | #include <xlist.h> |
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31 | #include <grdxt.h> |
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32 | #include <rwlock.h> |
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33 | |
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34 | /**** Forward declarations ****/ |
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35 | |
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36 | struct page_s; |
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37 | struct vfs_inode_s; |
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38 | |
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39 | /******************************************************************************************* |
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40 | * This mapper_t object implements the kernel cache for a given VFS file or directory. |
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41 | * There is one mapper per file/dir. It is implemented as a three levels radix tree, |
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42 | * entirely stored in the same cluster as the inode representing the file/dir. |
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43 | * - The fast retrieval key is the page index in the file. |
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44 | * The ix1_width, ix2_width, ix3_width sub-indexes are configuration parameters. |
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45 | * - The leaves are pointers on physical page descriptors, dynamically allocated |
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46 | * in the local cluster. |
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47 | * - The mapper is protected by a "remote_rwlock", to support several simultaneous |
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48 | * "readers", and only one "writer". |
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49 | * - A "reader" thread, calling the mapper_remote_get_page() function to get a page |
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50 | * descriptor pointer from the page index in file, can be running in any cluster. |
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51 | * - A "writer" thread, calling the mapper_handle_miss() function to handle a page miss |
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52 | * must be local (running in the mapper cluster). |
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53 | * - The vfs_fs_move_page() function access the file system to handle a mapper miss, |
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54 | * or update a dirty page on device. |
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55 | * - The vfs_mapper_load_all() functions is used to load all pages of a directory |
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56 | * into the mapper (prefetch). |
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57 | * - the mapper_move_user() function is used to move data to or from an user buffer. |
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58 | * This user space buffer can be physically distributed in several clusters. |
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59 | * - the mapper_move_kernel() function is used to move data to or from a remote kernel |
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60 | * buffer, that can be physically located in any cluster. |
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61 | * - In the present implementation the cache size for a given file increases on demand, |
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62 | * and the allocated memory is only released when the mapper/inode is destroyed. |
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63 | * |
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64 | * TODO : the mapper being only used to implement the VFS cache(s), the mapper.c |
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65 | * and mapper.h file should be trandfered to the fs directory. |
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66 | ******************************************************************************************/ |
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67 | |
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68 | |
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69 | /******************************************************************************************* |
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70 | * This structure defines the mapper descriptor. |
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71 | ******************************************************************************************/ |
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72 | |
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73 | typedef struct mapper_s |
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74 | { |
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75 | struct vfs_inode_s * inode; /*! owner inode */ |
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76 | uint32_t type; /*! file system type */ |
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77 | grdxt_t rt; /*! embedded pages cache descriptor (radix tree) */ |
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78 | remote_rwlock_t lock; /*! several readers / only one writer */ |
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79 | uint32_t refcount; /*! several vsegs can refer the same file */ |
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80 | xlist_entry_t vsegs_root; /*! root of list of vsegs refering this mapper */ |
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81 | xlist_entry_t wait_root; /*! root of list of threads waiting on mapper */ |
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82 | list_entry_t dirty_root; /*! root of list of dirty pages */ |
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83 | } |
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84 | mapper_t; |
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85 | |
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86 | /******************************************************************************************* |
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87 | * This function allocates physical memory for a mapper descriptor, and initializes it |
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88 | * (refcount <= 0) / inode <= NULL). |
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89 | * It must be executed by a thread running in the cluster containing the mapper. |
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90 | ******************************************************************************************* |
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91 | * @ type : type of the mapper to create. |
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92 | * @ return : pointer on created mapper if success / return NULL if no memory |
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93 | ******************************************************************************************/ |
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94 | mapper_t * mapper_create( vfs_fs_type_t type ); |
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95 | |
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96 | /******************************************************************************************* |
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97 | * This function releases all physical memory allocated for a mapper. |
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98 | * Both the mapper descriptor and the radix tree are released. |
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99 | * It does NOT synchronize dirty pages. Use the vfs_sync_inode() function if required. |
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100 | * It must be executed by a thread running in the cluster containing the mapper. |
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101 | ******************************************************************************************* |
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102 | * @ mapper : target mapper. |
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103 | ******************************************************************************************/ |
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104 | void mapper_destroy( mapper_t * mapper ); |
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105 | |
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106 | /******************************************************************************************* |
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107 | * This function load from device a missing page identified by the <page_id> argument |
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108 | * into the mapper identified by the <mapper> local pointer. |
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109 | * It allocates a physical page from the local cluster, initialise by accessing device, |
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110 | * and register the page in the mapper radix tree. |
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111 | * It must be executed by a thread running in the cluster containing the mapper. |
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112 | * WARNING : the calling function mapper_remote_get_page() is supposed to take and release |
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113 | * the lock protecting the mapper in WRITE_MODE. |
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114 | ******************************************************************************************* |
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115 | * @ mapper : [in] target mapper. |
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116 | * @ page_id : [in] missing page index in file. |
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117 | * @ page_xp : [out] buffer for extended pointer on missing page descriptor. |
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118 | * @ return 0 if success / return -1 if a dirty page cannot be updated on device. |
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119 | ******************************************************************************************/ |
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120 | error_t mapper_handle_miss( mapper_t * mapper, |
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121 | uint32_t page_id, |
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122 | xptr_t * page_xp ); |
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123 | |
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124 | /******************************************************************************************* |
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125 | * This function move data between a remote mapper, dentified by the <mapper_xp> argument, |
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126 | * and a distributed user buffer. It can be called by a thread running in any cluster. |
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127 | * It is called by the vfs_user_move() to implement sys_read() and sys_write() syscalls. |
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128 | * If required, the data transfer is split in "fragments", where one fragment contains |
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129 | * contiguous bytes in the same mapper page. |
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130 | * It uses "hal_uspace" accesses to move a fragment to/from the user buffer. |
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131 | * In case of write, the dirty bit is set for all pages written in the mapper. |
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132 | * The mapper being an extendable cache, it is automatically extended when required. |
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133 | * The "offset" field in the file descriptor, and the "size" field in inode descriptor |
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134 | * are not modified by this function. |
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135 | ******************************************************************************************* |
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136 | * @ mapper_xp : extended pointer on mapper. |
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137 | * @ to_buffer : mapper -> buffer if true / buffer -> mapper if false. |
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138 | * @ file_offset : first byte to move in file. |
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139 | * @ u_buf : user space pointer on user buffer. |
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140 | * @ size : number of bytes to move. |
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141 | * returns O if success / returns -1 if error. |
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142 | ******************************************************************************************/ |
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143 | error_t mapper_move_user( xptr_t mapper_xp, |
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144 | bool_t to_buffer, |
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145 | uint32_t file_offset, |
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146 | void * u_buf, |
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147 | uint32_t size ); |
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148 | |
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149 | /******************************************************************************************** |
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150 | * This function move data between a remote mapper and a remote kernel buffer. |
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151 | * It can be called by a thread running any cluster. |
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152 | * If required, the data transfer is split in "fragments", where one fragment contains |
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153 | * contiguous bytes in the same mapper page. |
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154 | * It uses a "remote_memcpy" to move a fragment to/from the kernel buffer. |
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155 | * In case of write, the dirty bit is set for all pages written in the mapper. |
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156 | ******************************************************************************************* |
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157 | * @ mapper_xp : extended pointer on mapper. |
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158 | * @ to_buffer : mapper -> buffer if true / buffer -> mapper if false. |
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159 | * @ file_offset : first byte to move in file. |
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160 | * @ buffer_xp : extended pointer on kernel buffer. |
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161 | * @ size : number of bytes to move. |
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162 | * returns O if success / returns -1 if error. |
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163 | ******************************************************************************************/ |
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164 | error_t mapper_move_kernel( xptr_t mapper_xp, |
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165 | bool_t to_buffer, |
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166 | uint32_t file_offset, |
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167 | xptr_t buffer_xp, |
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168 | uint32_t size ); |
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169 | |
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170 | /******************************************************************************************* |
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171 | * This function removes a physical page from the mapper, and releases |
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172 | * the page to the local PPM. It is called by the mapper_destroy() function. |
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173 | * It must be executed by a thread running in the cluster containing the mapper. |
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174 | * It takes the mapper lock in WRITE_MODE to update the mapper. |
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175 | ******************************************************************************************* |
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176 | * @ mapper : local pointer on the mapper. |
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177 | * @ page : pointer on page to remove. |
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178 | ******************************************************************************************/ |
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179 | void mapper_release_page( mapper_t * mapper, |
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180 | struct page_s * page ); |
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181 | |
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182 | /******************************************************************************************* |
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183 | * This function returns an extended pointer on a page descriptor. |
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184 | * The - possibly remote - mapper is identified by the <mapper_xp> argument. |
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185 | * The page is identified by <page_id> argument (page index in the file). |
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186 | * It can be executed by a thread running in any cluster, as it uses remote |
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187 | * access primitives to scan the mapper. |
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188 | * In case of miss, this function takes the mapper lock in WRITE_MODE, and call the |
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189 | * mapper_handle_miss() to load the missing page from device to mapper, using an RPC |
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190 | * when the mapper is remote. |
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191 | ******************************************************************************************* |
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192 | * @ mapper_xp : extended pointer on the mapper. |
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193 | * @ page_id : page index in file |
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194 | * @ returns extended pointer on page descriptor if success / return XPTR_NULL if error. |
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195 | ******************************************************************************************/ |
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196 | xptr_t mapper_remote_get_page( xptr_t mapper_xp, |
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197 | uint32_t page_id ); |
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198 | |
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199 | /******************************************************************************************* |
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200 | * This function allows to read a single word in a mapper seen as and array of uint32_t. |
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201 | * It has bee designed to support remote access to the FAT mapper of the FATFS. |
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202 | * It can be called by any thread running in any cluster. |
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203 | * In case of miss, it takes the mapper lock in WRITE_MODE, load the missing |
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204 | * page from device to mapper, and release the mapper lock. |
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205 | ******************************************************************************************* |
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206 | * @ mapper_xp : [in] extended pointer on the mapper. |
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207 | * @ word_id : [in] 32 bits word index in file. |
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208 | * @ p_value : [out] local pointer on destination buffer. |
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209 | * @ returns 0 if success / return -1 if error. |
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210 | ******************************************************************************************/ |
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211 | error_t mapper_remote_get_32( xptr_t mapper_xp, |
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212 | uint32_t word_id, |
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213 | uint32_t * p_value ); |
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214 | |
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215 | /******************************************************************************************* |
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216 | * This function allows to write a single word to a mapper seen as and array of uint32_t. |
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217 | * It has bee designed to support remote access tho the FAT mapper of the FATFS. |
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218 | * It can be called by any thread running in any cluster. |
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219 | * In case of miss, it takes the mapper lock in WRITE_MODE, load the missing |
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220 | * page from device to mapper, and release the mapper lock. |
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221 | ******************************************************************************************* |
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222 | * @ mapper_xp : [in] extended pointer on the mapper. |
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223 | * @ word_id : [in] 32 bits word index in file. |
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224 | * @ value : [in] value to be written. |
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225 | * @ returns 0 if success / return -1 if error. |
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226 | ******************************************************************************************/ |
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227 | error_t mapper_remote_set_32( xptr_t mapper_xp, |
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228 | uint32_t word_id, |
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229 | uint32_t value ); |
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230 | |
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231 | /******************************************************************************************* |
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232 | * This scans all pages present in the mapper identified by the <mapper> argument, |
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233 | * and synchronize all pages maked as dirty" on disk. |
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234 | * These pages are unmarked and removed from the local PPM dirty_list. |
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235 | * This function must be called by a local thread running in same cluster as the mapper. |
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236 | * A remote thread must call the RPC_MAPPER_SYNC function. |
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237 | ******************************************************************************************* |
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238 | * @ mapper : [in] local pointer on local mapper. |
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239 | * @ returns 0 if success / return -1 if error. |
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240 | ******************************************************************************************/ |
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241 | error_t mapper_sync( mapper_t * mapper ); |
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242 | |
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243 | /******************************************************************************************* |
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244 | * This debug function displays the content of a given page of a given mapper. |
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245 | * - the mapper is identified by the <mapper_xp> argument. |
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246 | * - the page is identified by the <page_id> argument. |
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247 | * - the number of bytes to display in page is defined by the <nbytes> argument. |
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248 | * The format is eigth (32 bits) words per line in hexadecimal. |
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249 | * It can be called by any thread running in any cluster. |
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250 | * In case of miss in mapper, it load the missing page from device to mapper. |
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251 | ******************************************************************************************* |
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252 | * @ mapper_xp : [in] extended pointer on the mapper. |
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253 | * @ page_id : [in] page index in file. |
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254 | * @ nbytes : [in] value to be written. |
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255 | * @ returns 0 if success / return -1 if error. |
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256 | ******************************************************************************************/ |
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257 | error_t mapper_display_page( xptr_t mapper_xp, |
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258 | uint32_t page_id, |
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259 | uint32_t nbytes ); |
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260 | |
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261 | |
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262 | #endif /* _MAPPER_H_ */ |
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