1 | /** |
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2 | * @file |
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3 | * |
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4 | * @ingroup rtems_bdbuf |
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5 | * |
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6 | * Block device buffer management. |
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7 | */ |
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8 | |
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9 | /* |
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10 | * Disk I/O buffering |
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11 | * Buffer managment |
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12 | * |
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13 | * Copyright (C) 2001 OKTET Ltd., St.-Peterburg, Russia |
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14 | * Author: Andrey G. Ivanov <Andrey.Ivanov@oktet.ru> |
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15 | * Victor V. Vengerov <vvv@oktet.ru> |
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16 | * Alexander Kukuta <kam@oktet.ru> |
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17 | * |
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18 | * Copyright (C) 2008,2009 Chris Johns <chrisj@rtems.org> |
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19 | * Rewritten to remove score mutex access. Fixes many performance |
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20 | * issues. |
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21 | * |
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22 | * Copyright (c) 2009-2014 embedded brains GmbH. |
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23 | */ |
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24 | |
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25 | /** |
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26 | * Set to 1 to enable debug tracing. |
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27 | */ |
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28 | #define RTEMS_BDBUF_TRACE 0 |
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29 | |
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30 | #if HAVE_CONFIG_H |
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31 | #include "config.h" |
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32 | #endif |
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33 | #include <limits.h> |
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34 | #include <errno.h> |
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35 | #include <stdio.h> |
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36 | #include <string.h> |
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37 | #include <inttypes.h> |
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38 | #include <pthread.h> |
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39 | |
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40 | #include <rtems.h> |
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41 | #include <rtems/error.h> |
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42 | |
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43 | #include "rtems/bdbuf.h" |
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44 | |
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45 | #define BDBUF_INVALID_DEV NULL |
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46 | |
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47 | /* |
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48 | * Simpler label for this file. |
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49 | */ |
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50 | #define bdbuf_config rtems_bdbuf_configuration |
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51 | |
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52 | /** |
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53 | * A swapout transfer transaction data. This data is passed to a worked thread |
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54 | * to handle the write phase of the transfer. |
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55 | */ |
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56 | typedef struct rtems_bdbuf_swapout_transfer |
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57 | { |
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58 | rtems_chain_control bds; /**< The transfer list of BDs. */ |
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59 | rtems_disk_device *dd; /**< The device the transfer is for. */ |
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60 | bool syncing; /**< The data is a sync'ing. */ |
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61 | rtems_blkdev_request write_req; /**< The write request. */ |
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62 | } rtems_bdbuf_swapout_transfer; |
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63 | |
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64 | /** |
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65 | * Swapout worker thread. These are available to take processing from the |
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66 | * main swapout thread and handle the I/O operation. |
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67 | */ |
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68 | typedef struct rtems_bdbuf_swapout_worker |
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69 | { |
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70 | rtems_chain_node link; /**< The threads sit on a chain when |
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71 | * idle. */ |
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72 | rtems_id id; /**< The id of the task so we can wake |
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73 | * it. */ |
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74 | bool enabled; /**< The worker is enabled. */ |
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75 | rtems_bdbuf_swapout_transfer transfer; /**< The transfer data for this |
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76 | * thread. */ |
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77 | } rtems_bdbuf_swapout_worker; |
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78 | |
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79 | #if defined(RTEMS_BDBUF_USE_PTHREAD) |
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80 | typedef pthread_mutex_t rtems_bdbuf_lock_type; |
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81 | #else |
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82 | typedef rtems_id rtems_bdbuf_lock_type; |
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83 | #endif |
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84 | |
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85 | /** |
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86 | * Buffer waiters synchronization. |
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87 | */ |
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88 | typedef struct rtems_bdbuf_waiters { |
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89 | unsigned count; |
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90 | #if defined(RTEMS_BDBUF_USE_PTHREAD) |
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91 | pthread_cond_t cond_var; |
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92 | #else |
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93 | rtems_id sema; |
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94 | #endif |
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95 | } rtems_bdbuf_waiters; |
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96 | |
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97 | /** |
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98 | * The BD buffer cache. |
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99 | */ |
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100 | typedef struct rtems_bdbuf_cache |
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101 | { |
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102 | rtems_id swapout; /**< Swapout task ID */ |
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103 | bool swapout_enabled; /**< Swapout is only running if |
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104 | * enabled. Set to false to kill the |
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105 | * swap out task. It deletes itself. */ |
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106 | rtems_chain_control swapout_free_workers; /**< The work threads for the swapout |
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107 | * task. */ |
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108 | |
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109 | rtems_bdbuf_buffer* bds; /**< Pointer to table of buffer |
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110 | * descriptors. */ |
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111 | void* buffers; /**< The buffer's memory. */ |
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112 | size_t buffer_min_count; /**< Number of minimum size buffers |
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113 | * that fit the buffer memory. */ |
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114 | size_t max_bds_per_group; /**< The number of BDs of minimum |
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115 | * buffer size that fit in a group. */ |
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116 | uint32_t flags; /**< Configuration flags. */ |
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117 | |
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118 | rtems_bdbuf_lock_type lock; /**< The cache lock. It locks all |
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119 | * cache data, BD and lists. */ |
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120 | rtems_bdbuf_lock_type sync_lock; /**< Sync calls block writes. */ |
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121 | bool sync_active; /**< True if a sync is active. */ |
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122 | rtems_id sync_requester; /**< The sync requester. */ |
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123 | rtems_disk_device *sync_device; /**< The device to sync and |
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124 | * BDBUF_INVALID_DEV not a device |
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125 | * sync. */ |
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126 | |
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127 | rtems_bdbuf_buffer* tree; /**< Buffer descriptor lookup AVL tree |
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128 | * root. There is only one. */ |
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129 | rtems_chain_control lru; /**< Least recently used list */ |
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130 | rtems_chain_control modified; /**< Modified buffers list */ |
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131 | rtems_chain_control sync; /**< Buffers to sync list */ |
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132 | |
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133 | rtems_bdbuf_waiters access_waiters; /**< Wait for a buffer in |
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134 | * ACCESS_CACHED, ACCESS_MODIFIED or |
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135 | * ACCESS_EMPTY |
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136 | * state. */ |
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137 | rtems_bdbuf_waiters transfer_waiters; /**< Wait for a buffer in TRANSFER |
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138 | * state. */ |
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139 | rtems_bdbuf_waiters buffer_waiters; /**< Wait for a buffer and no one is |
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140 | * available. */ |
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141 | |
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142 | rtems_bdbuf_swapout_transfer *swapout_transfer; |
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143 | rtems_bdbuf_swapout_worker *swapout_workers; |
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144 | |
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145 | size_t group_count; /**< The number of groups. */ |
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146 | rtems_bdbuf_group* groups; /**< The groups. */ |
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147 | rtems_id read_ahead_task; /**< Read-ahead task */ |
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148 | rtems_chain_control read_ahead_chain; /**< Read-ahead request chain */ |
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149 | bool read_ahead_enabled; /**< Read-ahead enabled */ |
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150 | rtems_status_code init_status; /**< The initialization status */ |
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151 | } rtems_bdbuf_cache; |
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152 | |
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153 | typedef enum { |
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154 | RTEMS_BDBUF_FATAL_CACHE_LOCK, |
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155 | RTEMS_BDBUF_FATAL_CACHE_UNLOCK, |
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156 | RTEMS_BDBUF_FATAL_CACHE_WAIT_2, |
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157 | RTEMS_BDBUF_FATAL_CACHE_WAIT_TO, |
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158 | RTEMS_BDBUF_FATAL_CACHE_WAKE, |
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159 | RTEMS_BDBUF_FATAL_PREEMPT_DIS, |
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160 | RTEMS_BDBUF_FATAL_PREEMPT_RST, |
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161 | RTEMS_BDBUF_FATAL_RA_WAKE_UP, |
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162 | RTEMS_BDBUF_FATAL_RECYCLE, |
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163 | RTEMS_BDBUF_FATAL_SO_WAKE_1, |
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164 | RTEMS_BDBUF_FATAL_SO_WAKE_2, |
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165 | RTEMS_BDBUF_FATAL_STATE_0, |
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166 | RTEMS_BDBUF_FATAL_STATE_2, |
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167 | RTEMS_BDBUF_FATAL_STATE_4, |
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168 | RTEMS_BDBUF_FATAL_STATE_5, |
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169 | RTEMS_BDBUF_FATAL_STATE_6, |
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170 | RTEMS_BDBUF_FATAL_STATE_7, |
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171 | RTEMS_BDBUF_FATAL_STATE_8, |
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172 | RTEMS_BDBUF_FATAL_STATE_9, |
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173 | RTEMS_BDBUF_FATAL_STATE_10, |
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174 | RTEMS_BDBUF_FATAL_STATE_11, |
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175 | RTEMS_BDBUF_FATAL_SWAPOUT_RE, |
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176 | RTEMS_BDBUF_FATAL_SYNC_LOCK, |
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177 | RTEMS_BDBUF_FATAL_SYNC_UNLOCK, |
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178 | RTEMS_BDBUF_FATAL_TREE_RM, |
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179 | RTEMS_BDBUF_FATAL_WAIT_EVNT, |
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180 | RTEMS_BDBUF_FATAL_WAIT_TRANS_EVNT, |
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181 | RTEMS_BDBUF_FATAL_ONCE, |
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182 | RTEMS_BDBUF_FATAL_MTX_ATTR_INIT, |
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183 | RTEMS_BDBUF_FATAL_MTX_ATTR_SETPROTO, |
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184 | RTEMS_BDBUF_FATAL_CV_WAIT, |
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185 | RTEMS_BDBUF_FATAL_CV_BROADCAST |
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186 | } rtems_bdbuf_fatal_code; |
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187 | |
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188 | /** |
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189 | * The events used in this code. These should be system events rather than |
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190 | * application events. |
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191 | */ |
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192 | #define RTEMS_BDBUF_SWAPOUT_SYNC RTEMS_EVENT_2 |
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193 | #define RTEMS_BDBUF_READ_AHEAD_WAKE_UP RTEMS_EVENT_1 |
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194 | |
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195 | /** |
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196 | * Lock semaphore attributes. This is used for locking type mutexes. |
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197 | * |
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198 | * @warning Priority inheritance is on. |
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199 | */ |
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200 | #define RTEMS_BDBUF_CACHE_LOCK_ATTRIBS \ |
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201 | (RTEMS_PRIORITY | RTEMS_BINARY_SEMAPHORE | \ |
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202 | RTEMS_INHERIT_PRIORITY | RTEMS_NO_PRIORITY_CEILING | RTEMS_LOCAL) |
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203 | |
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204 | /** |
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205 | * Waiter semaphore attributes. |
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206 | * |
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207 | * @warning Do not configure as inherit priority. If a driver is in the driver |
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208 | * initialisation table this locked semaphore will have the IDLE task |
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209 | * as the holder and a blocking task will raise the priority of the |
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210 | * IDLE task which can cause unsual side effects. |
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211 | */ |
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212 | #define RTEMS_BDBUF_CACHE_WAITER_ATTRIBS \ |
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213 | (RTEMS_PRIORITY | RTEMS_SIMPLE_BINARY_SEMAPHORE | \ |
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214 | RTEMS_NO_INHERIT_PRIORITY | RTEMS_NO_PRIORITY_CEILING | RTEMS_LOCAL) |
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215 | |
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216 | /** |
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217 | * Waiter timeout. Set to non-zero to find some info on a waiter that is |
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218 | * waiting too long. |
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219 | */ |
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220 | #define RTEMS_BDBUF_WAIT_TIMEOUT RTEMS_NO_TIMEOUT |
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221 | #if !defined (RTEMS_BDBUF_WAIT_TIMEOUT) |
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222 | #define RTEMS_BDBUF_WAIT_TIMEOUT \ |
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223 | (RTEMS_MICROSECONDS_TO_TICKS (20000000)) |
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224 | #endif |
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225 | |
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226 | static rtems_task rtems_bdbuf_swapout_task(rtems_task_argument arg); |
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227 | |
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228 | static rtems_task rtems_bdbuf_read_ahead_task(rtems_task_argument arg); |
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229 | |
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230 | /** |
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231 | * The Buffer Descriptor cache. |
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232 | */ |
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233 | static rtems_bdbuf_cache bdbuf_cache; |
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234 | |
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235 | static pthread_once_t rtems_bdbuf_once_state = PTHREAD_ONCE_INIT; |
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236 | |
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237 | #if RTEMS_BDBUF_TRACE |
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238 | /** |
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239 | * If true output the trace message. |
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240 | */ |
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241 | bool rtems_bdbuf_tracer; |
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242 | |
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243 | /** |
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244 | * Return the number of items on the list. |
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245 | * |
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246 | * @param list The chain control. |
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247 | * @return uint32_t The number of items on the list. |
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248 | */ |
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249 | uint32_t |
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250 | rtems_bdbuf_list_count (rtems_chain_control* list) |
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251 | { |
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252 | rtems_chain_node* node = rtems_chain_first (list); |
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253 | uint32_t count = 0; |
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254 | while (!rtems_chain_is_tail (list, node)) |
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255 | { |
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256 | count++; |
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257 | node = rtems_chain_next (node); |
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258 | } |
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259 | return count; |
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260 | } |
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261 | |
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262 | /** |
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263 | * Show the usage for the bdbuf cache. |
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264 | */ |
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265 | void |
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266 | rtems_bdbuf_show_usage (void) |
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267 | { |
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268 | uint32_t group; |
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269 | uint32_t total = 0; |
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270 | uint32_t val; |
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271 | |
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272 | for (group = 0; group < bdbuf_cache.group_count; group++) |
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273 | total += bdbuf_cache.groups[group].users; |
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274 | printf ("bdbuf:group users=%lu", total); |
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275 | val = rtems_bdbuf_list_count (&bdbuf_cache.lru); |
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276 | printf (", lru=%lu", val); |
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277 | total = val; |
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278 | val = rtems_bdbuf_list_count (&bdbuf_cache.modified); |
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279 | printf (", mod=%lu", val); |
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280 | total += val; |
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281 | val = rtems_bdbuf_list_count (&bdbuf_cache.sync); |
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282 | printf (", sync=%lu", val); |
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283 | total += val; |
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284 | printf (", total=%lu\n", total); |
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285 | } |
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286 | |
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287 | /** |
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288 | * Show the users for a group of a bd. |
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289 | * |
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290 | * @param where A label to show the context of output. |
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291 | * @param bd The bd to show the users of. |
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292 | */ |
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293 | void |
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294 | rtems_bdbuf_show_users (const char* where, rtems_bdbuf_buffer* bd) |
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295 | { |
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296 | const char* states[] = |
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297 | { "FR", "EM", "CH", "AC", "AM", "AE", "AP", "MD", "SY", "TR", "TP" }; |
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298 | |
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299 | printf ("bdbuf:users: %15s: [%" PRIu32 " (%s)] %td:%td = %" PRIu32 " %s\n", |
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300 | where, |
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301 | bd->block, states[bd->state], |
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302 | bd->group - bdbuf_cache.groups, |
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303 | bd - bdbuf_cache.bds, |
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304 | bd->group->users, |
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305 | bd->group->users > 8 ? "<<<<<<<" : ""); |
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306 | } |
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307 | #else |
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308 | #define rtems_bdbuf_tracer (0) |
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309 | #define rtems_bdbuf_show_usage() ((void) 0) |
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310 | #define rtems_bdbuf_show_users(_w, _b) ((void) 0) |
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311 | #endif |
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312 | |
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313 | /** |
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314 | * The default maximum height of 32 allows for AVL trees having between |
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315 | * 5,704,880 and 4,294,967,295 nodes, depending on order of insertion. You may |
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316 | * change this compile-time constant as you wish. |
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317 | */ |
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318 | #ifndef RTEMS_BDBUF_AVL_MAX_HEIGHT |
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319 | #define RTEMS_BDBUF_AVL_MAX_HEIGHT (32) |
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320 | #endif |
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321 | |
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322 | static void |
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323 | rtems_bdbuf_fatal (rtems_fatal_code error) |
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324 | { |
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325 | rtems_fatal (RTEMS_FATAL_SOURCE_BDBUF, error); |
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326 | } |
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327 | |
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328 | static void |
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329 | rtems_bdbuf_fatal_with_state (rtems_bdbuf_buf_state state, |
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330 | rtems_bdbuf_fatal_code error) |
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331 | { |
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332 | rtems_bdbuf_fatal ((((uint32_t) state) << 16) | error); |
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333 | } |
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334 | |
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335 | static rtems_status_code |
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336 | rtems_bdbuf_lock_create (rtems_name name, rtems_bdbuf_lock_type *lock) |
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337 | { |
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338 | #if defined(RTEMS_BDBUF_USE_PTHREAD) |
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339 | int eno; |
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340 | pthread_mutexattr_t attr; |
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341 | |
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342 | (void) name; |
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343 | |
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344 | eno = pthread_mutexattr_init (&attr); |
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345 | if (eno != 0) |
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346 | rtems_bdbuf_fatal (RTEMS_BDBUF_FATAL_MTX_ATTR_INIT); |
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347 | |
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348 | eno = pthread_mutexattr_setprotocol (&attr, PTHREAD_PRIO_INHERIT); |
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349 | if (eno != 0) |
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350 | rtems_bdbuf_fatal (RTEMS_BDBUF_FATAL_MTX_ATTR_SETPROTO); |
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351 | |
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352 | eno = pthread_mutex_init (lock, &attr); |
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353 | |
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354 | pthread_mutexattr_destroy (&attr); |
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355 | |
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356 | if (eno != 0) |
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357 | return RTEMS_UNSATISFIED; |
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358 | |
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359 | return RTEMS_SUCCESSFUL; |
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360 | #else |
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361 | return rtems_semaphore_create( |
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362 | name, |
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363 | 1, |
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364 | RTEMS_BDBUF_CACHE_LOCK_ATTRIBS, |
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365 | 0, |
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366 | lock |
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367 | ); |
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368 | #endif |
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369 | } |
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370 | |
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371 | static void |
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372 | rtems_bdbuf_lock_delete (rtems_bdbuf_lock_type *lock) |
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373 | { |
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374 | #if defined(RTEMS_BDBUF_USE_PTHREAD) |
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375 | pthread_mutex_destroy (lock); |
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376 | #else |
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377 | rtems_semaphore_delete (*lock); |
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378 | #endif |
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379 | } |
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380 | |
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381 | static rtems_status_code |
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382 | rtems_bdbuf_waiter_create (rtems_name name, rtems_bdbuf_waiters *waiter) |
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383 | { |
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384 | #if defined(RTEMS_BDBUF_USE_PTHREAD) |
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385 | int eno = pthread_cond_init (&waiter->cond_var, NULL); |
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386 | if (eno != 0) |
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387 | return RTEMS_UNSATISFIED; |
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388 | |
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389 | return RTEMS_SUCCESSFUL; |
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390 | #else |
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391 | return rtems_semaphore_create( |
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392 | name, |
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393 | 0, |
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394 | RTEMS_BDBUF_CACHE_WAITER_ATTRIBS, |
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395 | 0, |
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396 | &waiter->sema |
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397 | ); |
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398 | #endif |
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399 | } |
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400 | |
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401 | static void |
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402 | rtems_bdbuf_waiter_delete (rtems_bdbuf_waiters *waiter) |
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403 | { |
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404 | #if defined(RTEMS_BDBUF_USE_PTHREAD) |
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405 | pthread_cond_destroy (&waiter->cond_var); |
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406 | #else |
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407 | rtems_semaphore_delete (waiter->sema); |
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408 | #endif |
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409 | } |
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410 | |
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411 | /** |
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412 | * Searches for the node with specified dd/block. |
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413 | * |
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414 | * @param root pointer to the root node of the AVL-Tree |
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415 | * @param dd disk device search key |
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416 | * @param block block search key |
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417 | * @retval NULL node with the specified dd/block is not found |
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418 | * @return pointer to the node with specified dd/block |
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419 | */ |
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420 | static rtems_bdbuf_buffer * |
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421 | rtems_bdbuf_avl_search (rtems_bdbuf_buffer** root, |
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422 | const rtems_disk_device *dd, |
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423 | rtems_blkdev_bnum block) |
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424 | { |
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425 | rtems_bdbuf_buffer* p = *root; |
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426 | |
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427 | while ((p != NULL) && ((p->dd != dd) || (p->block != block))) |
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428 | { |
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429 | if (((uintptr_t) p->dd < (uintptr_t) dd) |
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430 | || ((p->dd == dd) && (p->block < block))) |
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431 | { |
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432 | p = p->avl.right; |
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433 | } |
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434 | else |
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435 | { |
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436 | p = p->avl.left; |
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437 | } |
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438 | } |
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439 | |
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440 | return p; |
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441 | } |
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442 | |
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443 | /** |
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444 | * Inserts the specified node to the AVl-Tree. |
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445 | * |
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446 | * @param root pointer to the root node of the AVL-Tree |
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447 | * @param node Pointer to the node to add. |
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448 | * @retval 0 The node added successfully |
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449 | * @retval -1 An error occured |
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450 | */ |
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451 | static int |
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452 | rtems_bdbuf_avl_insert(rtems_bdbuf_buffer** root, |
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453 | rtems_bdbuf_buffer* node) |
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454 | { |
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455 | const rtems_disk_device *dd = node->dd; |
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456 | rtems_blkdev_bnum block = node->block; |
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457 | |
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458 | rtems_bdbuf_buffer* p = *root; |
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459 | rtems_bdbuf_buffer* q; |
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460 | rtems_bdbuf_buffer* p1; |
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461 | rtems_bdbuf_buffer* p2; |
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462 | rtems_bdbuf_buffer* buf_stack[RTEMS_BDBUF_AVL_MAX_HEIGHT]; |
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463 | rtems_bdbuf_buffer** buf_prev = buf_stack; |
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464 | |
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465 | bool modified = false; |
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466 | |
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467 | if (p == NULL) |
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468 | { |
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469 | *root = node; |
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470 | node->avl.left = NULL; |
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471 | node->avl.right = NULL; |
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472 | node->avl.bal = 0; |
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473 | return 0; |
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474 | } |
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475 | |
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476 | while (p != NULL) |
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477 | { |
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478 | *buf_prev++ = p; |
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479 | |
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480 | if (((uintptr_t) p->dd < (uintptr_t) dd) |
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481 | || ((p->dd == dd) && (p->block < block))) |
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482 | { |
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483 | p->avl.cache = 1; |
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484 | q = p->avl.right; |
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485 | if (q == NULL) |
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486 | { |
---|
487 | q = node; |
---|
488 | p->avl.right = q = node; |
---|
489 | break; |
---|
490 | } |
---|
491 | } |
---|
492 | else if ((p->dd != dd) || (p->block != block)) |
---|
493 | { |
---|
494 | p->avl.cache = -1; |
---|
495 | q = p->avl.left; |
---|
496 | if (q == NULL) |
---|
497 | { |
---|
498 | q = node; |
---|
499 | p->avl.left = q; |
---|
500 | break; |
---|
501 | } |
---|
502 | } |
---|
503 | else |
---|
504 | { |
---|
505 | return -1; |
---|
506 | } |
---|
507 | |
---|
508 | p = q; |
---|
509 | } |
---|
510 | |
---|
511 | q->avl.left = q->avl.right = NULL; |
---|
512 | q->avl.bal = 0; |
---|
513 | modified = true; |
---|
514 | buf_prev--; |
---|
515 | |
---|
516 | while (modified) |
---|
517 | { |
---|
518 | if (p->avl.cache == -1) |
---|
519 | { |
---|
520 | switch (p->avl.bal) |
---|
521 | { |
---|
522 | case 1: |
---|
523 | p->avl.bal = 0; |
---|
524 | modified = false; |
---|
525 | break; |
---|
526 | |
---|
527 | case 0: |
---|
528 | p->avl.bal = -1; |
---|
529 | break; |
---|
530 | |
---|
531 | case -1: |
---|
532 | p1 = p->avl.left; |
---|
533 | if (p1->avl.bal == -1) /* simple LL-turn */ |
---|
534 | { |
---|
535 | p->avl.left = p1->avl.right; |
---|
536 | p1->avl.right = p; |
---|
537 | p->avl.bal = 0; |
---|
538 | p = p1; |
---|
539 | } |
---|
540 | else /* double LR-turn */ |
---|
541 | { |
---|
542 | p2 = p1->avl.right; |
---|
543 | p1->avl.right = p2->avl.left; |
---|
544 | p2->avl.left = p1; |
---|
545 | p->avl.left = p2->avl.right; |
---|
546 | p2->avl.right = p; |
---|
547 | if (p2->avl.bal == -1) p->avl.bal = +1; else p->avl.bal = 0; |
---|
548 | if (p2->avl.bal == +1) p1->avl.bal = -1; else p1->avl.bal = 0; |
---|
549 | p = p2; |
---|
550 | } |
---|
551 | p->avl.bal = 0; |
---|
552 | modified = false; |
---|
553 | break; |
---|
554 | |
---|
555 | default: |
---|
556 | break; |
---|
557 | } |
---|
558 | } |
---|
559 | else |
---|
560 | { |
---|
561 | switch (p->avl.bal) |
---|
562 | { |
---|
563 | case -1: |
---|
564 | p->avl.bal = 0; |
---|
565 | modified = false; |
---|
566 | break; |
---|
567 | |
---|
568 | case 0: |
---|
569 | p->avl.bal = 1; |
---|
570 | break; |
---|
571 | |
---|
572 | case 1: |
---|
573 | p1 = p->avl.right; |
---|
574 | if (p1->avl.bal == 1) /* simple RR-turn */ |
---|
575 | { |
---|
576 | p->avl.right = p1->avl.left; |
---|
577 | p1->avl.left = p; |
---|
578 | p->avl.bal = 0; |
---|
579 | p = p1; |
---|
580 | } |
---|
581 | else /* double RL-turn */ |
---|
582 | { |
---|
583 | p2 = p1->avl.left; |
---|
584 | p1->avl.left = p2->avl.right; |
---|
585 | p2->avl.right = p1; |
---|
586 | p->avl.right = p2->avl.left; |
---|
587 | p2->avl.left = p; |
---|
588 | if (p2->avl.bal == +1) p->avl.bal = -1; else p->avl.bal = 0; |
---|
589 | if (p2->avl.bal == -1) p1->avl.bal = +1; else p1->avl.bal = 0; |
---|
590 | p = p2; |
---|
591 | } |
---|
592 | p->avl.bal = 0; |
---|
593 | modified = false; |
---|
594 | break; |
---|
595 | |
---|
596 | default: |
---|
597 | break; |
---|
598 | } |
---|
599 | } |
---|
600 | q = p; |
---|
601 | if (buf_prev > buf_stack) |
---|
602 | { |
---|
603 | p = *--buf_prev; |
---|
604 | |
---|
605 | if (p->avl.cache == -1) |
---|
606 | { |
---|
607 | p->avl.left = q; |
---|
608 | } |
---|
609 | else |
---|
610 | { |
---|
611 | p->avl.right = q; |
---|
612 | } |
---|
613 | } |
---|
614 | else |
---|
615 | { |
---|
616 | *root = p; |
---|
617 | break; |
---|
618 | } |
---|
619 | }; |
---|
620 | |
---|
621 | return 0; |
---|
622 | } |
---|
623 | |
---|
624 | |
---|
625 | /** |
---|
626 | * Removes the node from the tree. |
---|
627 | * |
---|
628 | * @param root Pointer to pointer to the root node |
---|
629 | * @param node Pointer to the node to remove |
---|
630 | * @retval 0 Item removed |
---|
631 | * @retval -1 No such item found |
---|
632 | */ |
---|
633 | static int |
---|
634 | rtems_bdbuf_avl_remove(rtems_bdbuf_buffer** root, |
---|
635 | const rtems_bdbuf_buffer* node) |
---|
636 | { |
---|
637 | const rtems_disk_device *dd = node->dd; |
---|
638 | rtems_blkdev_bnum block = node->block; |
---|
639 | |
---|
640 | rtems_bdbuf_buffer* p = *root; |
---|
641 | rtems_bdbuf_buffer* q; |
---|
642 | rtems_bdbuf_buffer* r; |
---|
643 | rtems_bdbuf_buffer* s; |
---|
644 | rtems_bdbuf_buffer* p1; |
---|
645 | rtems_bdbuf_buffer* p2; |
---|
646 | rtems_bdbuf_buffer* buf_stack[RTEMS_BDBUF_AVL_MAX_HEIGHT]; |
---|
647 | rtems_bdbuf_buffer** buf_prev = buf_stack; |
---|
648 | |
---|
649 | bool modified = false; |
---|
650 | |
---|
651 | memset (buf_stack, 0, sizeof(buf_stack)); |
---|
652 | |
---|
653 | while (p != NULL) |
---|
654 | { |
---|
655 | *buf_prev++ = p; |
---|
656 | |
---|
657 | if (((uintptr_t) p->dd < (uintptr_t) dd) |
---|
658 | || ((p->dd == dd) && (p->block < block))) |
---|
659 | { |
---|
660 | p->avl.cache = 1; |
---|
661 | p = p->avl.right; |
---|
662 | } |
---|
663 | else if ((p->dd != dd) || (p->block != block)) |
---|
664 | { |
---|
665 | p->avl.cache = -1; |
---|
666 | p = p->avl.left; |
---|
667 | } |
---|
668 | else |
---|
669 | { |
---|
670 | /* node found */ |
---|
671 | break; |
---|
672 | } |
---|
673 | } |
---|
674 | |
---|
675 | if (p == NULL) |
---|
676 | { |
---|
677 | /* there is no such node */ |
---|
678 | return -1; |
---|
679 | } |
---|
680 | |
---|
681 | q = p; |
---|
682 | |
---|
683 | buf_prev--; |
---|
684 | if (buf_prev > buf_stack) |
---|
685 | { |
---|
686 | p = *(buf_prev - 1); |
---|
687 | } |
---|
688 | else |
---|
689 | { |
---|
690 | p = NULL; |
---|
691 | } |
---|
692 | |
---|
693 | /* at this moment q - is a node to delete, p is q's parent */ |
---|
694 | if (q->avl.right == NULL) |
---|
695 | { |
---|
696 | r = q->avl.left; |
---|
697 | if (r != NULL) |
---|
698 | { |
---|
699 | r->avl.bal = 0; |
---|
700 | } |
---|
701 | q = r; |
---|
702 | } |
---|
703 | else |
---|
704 | { |
---|
705 | rtems_bdbuf_buffer **t; |
---|
706 | |
---|
707 | r = q->avl.right; |
---|
708 | |
---|
709 | if (r->avl.left == NULL) |
---|
710 | { |
---|
711 | r->avl.left = q->avl.left; |
---|
712 | r->avl.bal = q->avl.bal; |
---|
713 | r->avl.cache = 1; |
---|
714 | *buf_prev++ = q = r; |
---|
715 | } |
---|
716 | else |
---|
717 | { |
---|
718 | t = buf_prev++; |
---|
719 | s = r; |
---|
720 | |
---|
721 | while (s->avl.left != NULL) |
---|
722 | { |
---|
723 | *buf_prev++ = r = s; |
---|
724 | s = r->avl.left; |
---|
725 | r->avl.cache = -1; |
---|
726 | } |
---|
727 | |
---|
728 | s->avl.left = q->avl.left; |
---|
729 | r->avl.left = s->avl.right; |
---|
730 | s->avl.right = q->avl.right; |
---|
731 | s->avl.bal = q->avl.bal; |
---|
732 | s->avl.cache = 1; |
---|
733 | |
---|
734 | *t = q = s; |
---|
735 | } |
---|
736 | } |
---|
737 | |
---|
738 | if (p != NULL) |
---|
739 | { |
---|
740 | if (p->avl.cache == -1) |
---|
741 | { |
---|
742 | p->avl.left = q; |
---|
743 | } |
---|
744 | else |
---|
745 | { |
---|
746 | p->avl.right = q; |
---|
747 | } |
---|
748 | } |
---|
749 | else |
---|
750 | { |
---|
751 | *root = q; |
---|
752 | } |
---|
753 | |
---|
754 | modified = true; |
---|
755 | |
---|
756 | while (modified) |
---|
757 | { |
---|
758 | if (buf_prev > buf_stack) |
---|
759 | { |
---|
760 | p = *--buf_prev; |
---|
761 | } |
---|
762 | else |
---|
763 | { |
---|
764 | break; |
---|
765 | } |
---|
766 | |
---|
767 | if (p->avl.cache == -1) |
---|
768 | { |
---|
769 | /* rebalance left branch */ |
---|
770 | switch (p->avl.bal) |
---|
771 | { |
---|
772 | case -1: |
---|
773 | p->avl.bal = 0; |
---|
774 | break; |
---|
775 | case 0: |
---|
776 | p->avl.bal = 1; |
---|
777 | modified = false; |
---|
778 | break; |
---|
779 | |
---|
780 | case +1: |
---|
781 | p1 = p->avl.right; |
---|
782 | |
---|
783 | if (p1->avl.bal >= 0) /* simple RR-turn */ |
---|
784 | { |
---|
785 | p->avl.right = p1->avl.left; |
---|
786 | p1->avl.left = p; |
---|
787 | |
---|
788 | if (p1->avl.bal == 0) |
---|
789 | { |
---|
790 | p1->avl.bal = -1; |
---|
791 | modified = false; |
---|
792 | } |
---|
793 | else |
---|
794 | { |
---|
795 | p->avl.bal = 0; |
---|
796 | p1->avl.bal = 0; |
---|
797 | } |
---|
798 | p = p1; |
---|
799 | } |
---|
800 | else /* double RL-turn */ |
---|
801 | { |
---|
802 | p2 = p1->avl.left; |
---|
803 | |
---|
804 | p1->avl.left = p2->avl.right; |
---|
805 | p2->avl.right = p1; |
---|
806 | p->avl.right = p2->avl.left; |
---|
807 | p2->avl.left = p; |
---|
808 | |
---|
809 | if (p2->avl.bal == +1) p->avl.bal = -1; else p->avl.bal = 0; |
---|
810 | if (p2->avl.bal == -1) p1->avl.bal = 1; else p1->avl.bal = 0; |
---|
811 | |
---|
812 | p = p2; |
---|
813 | p2->avl.bal = 0; |
---|
814 | } |
---|
815 | break; |
---|
816 | |
---|
817 | default: |
---|
818 | break; |
---|
819 | } |
---|
820 | } |
---|
821 | else |
---|
822 | { |
---|
823 | /* rebalance right branch */ |
---|
824 | switch (p->avl.bal) |
---|
825 | { |
---|
826 | case +1: |
---|
827 | p->avl.bal = 0; |
---|
828 | break; |
---|
829 | |
---|
830 | case 0: |
---|
831 | p->avl.bal = -1; |
---|
832 | modified = false; |
---|
833 | break; |
---|
834 | |
---|
835 | case -1: |
---|
836 | p1 = p->avl.left; |
---|
837 | |
---|
838 | if (p1->avl.bal <= 0) /* simple LL-turn */ |
---|
839 | { |
---|
840 | p->avl.left = p1->avl.right; |
---|
841 | p1->avl.right = p; |
---|
842 | if (p1->avl.bal == 0) |
---|
843 | { |
---|
844 | p1->avl.bal = 1; |
---|
845 | modified = false; |
---|
846 | } |
---|
847 | else |
---|
848 | { |
---|
849 | p->avl.bal = 0; |
---|
850 | p1->avl.bal = 0; |
---|
851 | } |
---|
852 | p = p1; |
---|
853 | } |
---|
854 | else /* double LR-turn */ |
---|
855 | { |
---|
856 | p2 = p1->avl.right; |
---|
857 | |
---|
858 | p1->avl.right = p2->avl.left; |
---|
859 | p2->avl.left = p1; |
---|
860 | p->avl.left = p2->avl.right; |
---|
861 | p2->avl.right = p; |
---|
862 | |
---|
863 | if (p2->avl.bal == -1) p->avl.bal = 1; else p->avl.bal = 0; |
---|
864 | if (p2->avl.bal == +1) p1->avl.bal = -1; else p1->avl.bal = 0; |
---|
865 | |
---|
866 | p = p2; |
---|
867 | p2->avl.bal = 0; |
---|
868 | } |
---|
869 | break; |
---|
870 | |
---|
871 | default: |
---|
872 | break; |
---|
873 | } |
---|
874 | } |
---|
875 | |
---|
876 | if (buf_prev > buf_stack) |
---|
877 | { |
---|
878 | q = *(buf_prev - 1); |
---|
879 | |
---|
880 | if (q->avl.cache == -1) |
---|
881 | { |
---|
882 | q->avl.left = p; |
---|
883 | } |
---|
884 | else |
---|
885 | { |
---|
886 | q->avl.right = p; |
---|
887 | } |
---|
888 | } |
---|
889 | else |
---|
890 | { |
---|
891 | *root = p; |
---|
892 | break; |
---|
893 | } |
---|
894 | |
---|
895 | } |
---|
896 | |
---|
897 | return 0; |
---|
898 | } |
---|
899 | |
---|
900 | static void |
---|
901 | rtems_bdbuf_set_state (rtems_bdbuf_buffer *bd, rtems_bdbuf_buf_state state) |
---|
902 | { |
---|
903 | bd->state = state; |
---|
904 | } |
---|
905 | |
---|
906 | static rtems_blkdev_bnum |
---|
907 | rtems_bdbuf_media_block (const rtems_disk_device *dd, rtems_blkdev_bnum block) |
---|
908 | { |
---|
909 | if (dd->block_to_media_block_shift >= 0) |
---|
910 | return block << dd->block_to_media_block_shift; |
---|
911 | else |
---|
912 | /* |
---|
913 | * Change the block number for the block size to the block number for the media |
---|
914 | * block size. We have to use 64bit maths. There is no short cut here. |
---|
915 | */ |
---|
916 | return (rtems_blkdev_bnum) |
---|
917 | ((((uint64_t) block) * dd->block_size) / dd->media_block_size); |
---|
918 | } |
---|
919 | |
---|
920 | /** |
---|
921 | * Lock the mutex. A single task can nest calls. |
---|
922 | * |
---|
923 | * @param lock The mutex to lock. |
---|
924 | * @param fatal_error_code The error code if the call fails. |
---|
925 | */ |
---|
926 | static void |
---|
927 | rtems_bdbuf_lock (rtems_bdbuf_lock_type *lock, uint32_t fatal_error_code) |
---|
928 | { |
---|
929 | #if defined(RTEMS_BDBUF_USE_PTHREAD) |
---|
930 | int eno = pthread_mutex_lock (lock); |
---|
931 | if (eno != 0) |
---|
932 | rtems_bdbuf_fatal (fatal_error_code); |
---|
933 | #else |
---|
934 | rtems_status_code sc = rtems_semaphore_obtain (*lock, |
---|
935 | RTEMS_WAIT, |
---|
936 | RTEMS_NO_TIMEOUT); |
---|
937 | if (sc != RTEMS_SUCCESSFUL) |
---|
938 | rtems_bdbuf_fatal (fatal_error_code); |
---|
939 | #endif |
---|
940 | } |
---|
941 | |
---|
942 | /** |
---|
943 | * Unlock the mutex. |
---|
944 | * |
---|
945 | * @param lock The mutex to unlock. |
---|
946 | * @param fatal_error_code The error code if the call fails. |
---|
947 | */ |
---|
948 | static void |
---|
949 | rtems_bdbuf_unlock (rtems_bdbuf_lock_type *lock, uint32_t fatal_error_code) |
---|
950 | { |
---|
951 | #if defined(RTEMS_BDBUF_USE_PTHREAD) |
---|
952 | int eno = pthread_mutex_unlock (lock); |
---|
953 | if (eno != 0) |
---|
954 | rtems_bdbuf_fatal (fatal_error_code); |
---|
955 | #else |
---|
956 | rtems_status_code sc = rtems_semaphore_release (*lock); |
---|
957 | if (sc != RTEMS_SUCCESSFUL) |
---|
958 | rtems_bdbuf_fatal (fatal_error_code); |
---|
959 | #endif |
---|
960 | } |
---|
961 | |
---|
962 | /** |
---|
963 | * Lock the cache. A single task can nest calls. |
---|
964 | */ |
---|
965 | static void |
---|
966 | rtems_bdbuf_lock_cache (void) |
---|
967 | { |
---|
968 | rtems_bdbuf_lock (&bdbuf_cache.lock, RTEMS_BDBUF_FATAL_CACHE_LOCK); |
---|
969 | } |
---|
970 | |
---|
971 | /** |
---|
972 | * Unlock the cache. |
---|
973 | */ |
---|
974 | static void |
---|
975 | rtems_bdbuf_unlock_cache (void) |
---|
976 | { |
---|
977 | rtems_bdbuf_unlock (&bdbuf_cache.lock, RTEMS_BDBUF_FATAL_CACHE_UNLOCK); |
---|
978 | } |
---|
979 | |
---|
980 | /** |
---|
981 | * Lock the cache's sync. A single task can nest calls. |
---|
982 | */ |
---|
983 | static void |
---|
984 | rtems_bdbuf_lock_sync (void) |
---|
985 | { |
---|
986 | rtems_bdbuf_lock (&bdbuf_cache.sync_lock, RTEMS_BDBUF_FATAL_SYNC_LOCK); |
---|
987 | } |
---|
988 | |
---|
989 | /** |
---|
990 | * Unlock the cache's sync lock. Any blocked writers are woken. |
---|
991 | */ |
---|
992 | static void |
---|
993 | rtems_bdbuf_unlock_sync (void) |
---|
994 | { |
---|
995 | rtems_bdbuf_unlock (&bdbuf_cache.sync_lock, |
---|
996 | RTEMS_BDBUF_FATAL_SYNC_UNLOCK); |
---|
997 | } |
---|
998 | |
---|
999 | static void |
---|
1000 | rtems_bdbuf_group_obtain (rtems_bdbuf_buffer *bd) |
---|
1001 | { |
---|
1002 | ++bd->group->users; |
---|
1003 | } |
---|
1004 | |
---|
1005 | static void |
---|
1006 | rtems_bdbuf_group_release (rtems_bdbuf_buffer *bd) |
---|
1007 | { |
---|
1008 | --bd->group->users; |
---|
1009 | } |
---|
1010 | |
---|
1011 | #if !defined(RTEMS_BDBUF_USE_PTHREAD) |
---|
1012 | static rtems_mode |
---|
1013 | rtems_bdbuf_disable_preemption (void) |
---|
1014 | { |
---|
1015 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
1016 | rtems_mode prev_mode = 0; |
---|
1017 | |
---|
1018 | sc = rtems_task_mode (RTEMS_NO_PREEMPT, RTEMS_PREEMPT_MASK, &prev_mode); |
---|
1019 | if (sc != RTEMS_SUCCESSFUL) |
---|
1020 | rtems_bdbuf_fatal (RTEMS_BDBUF_FATAL_PREEMPT_DIS); |
---|
1021 | |
---|
1022 | return prev_mode; |
---|
1023 | } |
---|
1024 | |
---|
1025 | static void |
---|
1026 | rtems_bdbuf_restore_preemption (rtems_mode prev_mode) |
---|
1027 | { |
---|
1028 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
1029 | |
---|
1030 | sc = rtems_task_mode (prev_mode, RTEMS_ALL_MODE_MASKS, &prev_mode); |
---|
1031 | if (sc != RTEMS_SUCCESSFUL) |
---|
1032 | rtems_bdbuf_fatal (RTEMS_BDBUF_FATAL_PREEMPT_RST); |
---|
1033 | } |
---|
1034 | #endif |
---|
1035 | |
---|
1036 | /** |
---|
1037 | * Wait until woken. Semaphores are used so a number of tasks can wait and can |
---|
1038 | * be woken at once. Task events would require we maintain a list of tasks to |
---|
1039 | * be woken and this would require storage and we do not know the number of |
---|
1040 | * tasks that could be waiting. |
---|
1041 | * |
---|
1042 | * While we have the cache locked we can try and claim the semaphore and |
---|
1043 | * therefore know when we release the lock to the cache we will block until the |
---|
1044 | * semaphore is released. This may even happen before we get to block. |
---|
1045 | * |
---|
1046 | * A counter is used to save the release call when no one is waiting. |
---|
1047 | * |
---|
1048 | * The function assumes the cache is locked on entry and it will be locked on |
---|
1049 | * exit. |
---|
1050 | */ |
---|
1051 | static void |
---|
1052 | rtems_bdbuf_anonymous_wait (rtems_bdbuf_waiters *waiters) |
---|
1053 | { |
---|
1054 | /* |
---|
1055 | * Indicate we are waiting. |
---|
1056 | */ |
---|
1057 | ++waiters->count; |
---|
1058 | |
---|
1059 | #if defined(RTEMS_BDBUF_USE_PTHREAD) |
---|
1060 | { |
---|
1061 | int eno = pthread_cond_wait (&waiters->cond_var, &bdbuf_cache.lock); |
---|
1062 | if (eno != 0) |
---|
1063 | rtems_bdbuf_fatal (RTEMS_BDBUF_FATAL_CV_WAIT); |
---|
1064 | } |
---|
1065 | #else |
---|
1066 | { |
---|
1067 | rtems_status_code sc; |
---|
1068 | rtems_mode prev_mode; |
---|
1069 | |
---|
1070 | /* |
---|
1071 | * Disable preemption then unlock the cache and block. There is no POSIX |
---|
1072 | * condition variable in the core API so this is a work around. |
---|
1073 | * |
---|
1074 | * The issue is a task could preempt after the cache is unlocked because it is |
---|
1075 | * blocking or just hits that window, and before this task has blocked on the |
---|
1076 | * semaphore. If the preempting task flushes the queue this task will not see |
---|
1077 | * the flush and may block for ever or until another transaction flushes this |
---|
1078 | * semaphore. |
---|
1079 | */ |
---|
1080 | prev_mode = rtems_bdbuf_disable_preemption(); |
---|
1081 | |
---|
1082 | /* |
---|
1083 | * Unlock the cache, wait, and lock the cache when we return. |
---|
1084 | */ |
---|
1085 | rtems_bdbuf_unlock_cache (); |
---|
1086 | |
---|
1087 | sc = rtems_semaphore_obtain (waiters->sema, RTEMS_WAIT, RTEMS_BDBUF_WAIT_TIMEOUT); |
---|
1088 | |
---|
1089 | if (sc == RTEMS_TIMEOUT) |
---|
1090 | rtems_bdbuf_fatal (RTEMS_BDBUF_FATAL_CACHE_WAIT_TO); |
---|
1091 | |
---|
1092 | if (sc != RTEMS_UNSATISFIED) |
---|
1093 | rtems_bdbuf_fatal (RTEMS_BDBUF_FATAL_CACHE_WAIT_2); |
---|
1094 | |
---|
1095 | rtems_bdbuf_lock_cache (); |
---|
1096 | |
---|
1097 | rtems_bdbuf_restore_preemption (prev_mode); |
---|
1098 | } |
---|
1099 | #endif |
---|
1100 | |
---|
1101 | --waiters->count; |
---|
1102 | } |
---|
1103 | |
---|
1104 | static void |
---|
1105 | rtems_bdbuf_wait (rtems_bdbuf_buffer *bd, rtems_bdbuf_waiters *waiters) |
---|
1106 | { |
---|
1107 | rtems_bdbuf_group_obtain (bd); |
---|
1108 | ++bd->waiters; |
---|
1109 | rtems_bdbuf_anonymous_wait (waiters); |
---|
1110 | --bd->waiters; |
---|
1111 | rtems_bdbuf_group_release (bd); |
---|
1112 | } |
---|
1113 | |
---|
1114 | /** |
---|
1115 | * Wake a blocked resource. The resource has a counter that lets us know if |
---|
1116 | * there are any waiters. |
---|
1117 | */ |
---|
1118 | static void |
---|
1119 | rtems_bdbuf_wake (rtems_bdbuf_waiters *waiters) |
---|
1120 | { |
---|
1121 | if (waiters->count > 0) |
---|
1122 | { |
---|
1123 | #if defined(RTEMS_BDBUF_USE_PTHREAD) |
---|
1124 | int eno = pthread_cond_broadcast (&waiters->cond_var); |
---|
1125 | if (eno != 0) |
---|
1126 | rtems_bdbuf_fatal (RTEMS_BDBUF_FATAL_CV_BROADCAST); |
---|
1127 | #else |
---|
1128 | rtems_status_code sc = rtems_semaphore_flush (waiters->sema); |
---|
1129 | if (sc != RTEMS_SUCCESSFUL) |
---|
1130 | rtems_bdbuf_fatal (RTEMS_BDBUF_FATAL_CACHE_WAKE); |
---|
1131 | #endif |
---|
1132 | } |
---|
1133 | } |
---|
1134 | |
---|
1135 | static void |
---|
1136 | rtems_bdbuf_wake_swapper (void) |
---|
1137 | { |
---|
1138 | rtems_status_code sc = rtems_event_send (bdbuf_cache.swapout, |
---|
1139 | RTEMS_BDBUF_SWAPOUT_SYNC); |
---|
1140 | if (sc != RTEMS_SUCCESSFUL) |
---|
1141 | rtems_bdbuf_fatal (RTEMS_BDBUF_FATAL_SO_WAKE_1); |
---|
1142 | } |
---|
1143 | |
---|
1144 | static bool |
---|
1145 | rtems_bdbuf_has_buffer_waiters (void) |
---|
1146 | { |
---|
1147 | return bdbuf_cache.buffer_waiters.count; |
---|
1148 | } |
---|
1149 | |
---|
1150 | static void |
---|
1151 | rtems_bdbuf_remove_from_tree (rtems_bdbuf_buffer *bd) |
---|
1152 | { |
---|
1153 | if (rtems_bdbuf_avl_remove (&bdbuf_cache.tree, bd) != 0) |
---|
1154 | rtems_bdbuf_fatal_with_state (bd->state, RTEMS_BDBUF_FATAL_TREE_RM); |
---|
1155 | } |
---|
1156 | |
---|
1157 | static void |
---|
1158 | rtems_bdbuf_remove_from_tree_and_lru_list (rtems_bdbuf_buffer *bd) |
---|
1159 | { |
---|
1160 | switch (bd->state) |
---|
1161 | { |
---|
1162 | case RTEMS_BDBUF_STATE_FREE: |
---|
1163 | break; |
---|
1164 | case RTEMS_BDBUF_STATE_CACHED: |
---|
1165 | rtems_bdbuf_remove_from_tree (bd); |
---|
1166 | break; |
---|
1167 | default: |
---|
1168 | rtems_bdbuf_fatal_with_state (bd->state, RTEMS_BDBUF_FATAL_STATE_10); |
---|
1169 | } |
---|
1170 | |
---|
1171 | rtems_chain_extract_unprotected (&bd->link); |
---|
1172 | } |
---|
1173 | |
---|
1174 | static void |
---|
1175 | rtems_bdbuf_make_free_and_add_to_lru_list (rtems_bdbuf_buffer *bd) |
---|
1176 | { |
---|
1177 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_FREE); |
---|
1178 | rtems_chain_prepend_unprotected (&bdbuf_cache.lru, &bd->link); |
---|
1179 | } |
---|
1180 | |
---|
1181 | static void |
---|
1182 | rtems_bdbuf_make_empty (rtems_bdbuf_buffer *bd) |
---|
1183 | { |
---|
1184 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_EMPTY); |
---|
1185 | } |
---|
1186 | |
---|
1187 | static void |
---|
1188 | rtems_bdbuf_make_cached_and_add_to_lru_list (rtems_bdbuf_buffer *bd) |
---|
1189 | { |
---|
1190 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_CACHED); |
---|
1191 | rtems_chain_append_unprotected (&bdbuf_cache.lru, &bd->link); |
---|
1192 | } |
---|
1193 | |
---|
1194 | static void |
---|
1195 | rtems_bdbuf_discard_buffer (rtems_bdbuf_buffer *bd) |
---|
1196 | { |
---|
1197 | rtems_bdbuf_make_empty (bd); |
---|
1198 | |
---|
1199 | if (bd->waiters == 0) |
---|
1200 | { |
---|
1201 | rtems_bdbuf_remove_from_tree (bd); |
---|
1202 | rtems_bdbuf_make_free_and_add_to_lru_list (bd); |
---|
1203 | } |
---|
1204 | } |
---|
1205 | |
---|
1206 | static void |
---|
1207 | rtems_bdbuf_add_to_modified_list_after_access (rtems_bdbuf_buffer *bd) |
---|
1208 | { |
---|
1209 | if (bdbuf_cache.sync_active && bdbuf_cache.sync_device == bd->dd) |
---|
1210 | { |
---|
1211 | rtems_bdbuf_unlock_cache (); |
---|
1212 | |
---|
1213 | /* |
---|
1214 | * Wait for the sync lock. |
---|
1215 | */ |
---|
1216 | rtems_bdbuf_lock_sync (); |
---|
1217 | |
---|
1218 | rtems_bdbuf_unlock_sync (); |
---|
1219 | rtems_bdbuf_lock_cache (); |
---|
1220 | } |
---|
1221 | |
---|
1222 | /* |
---|
1223 | * Only the first modified release sets the timer and any further user |
---|
1224 | * accesses do not change the timer value which should move down. This |
---|
1225 | * assumes the user's hold of the buffer is much less than the time on the |
---|
1226 | * modified list. Resetting the timer on each access which could result in a |
---|
1227 | * buffer never getting to 0 and never being forced onto disk. This raises a |
---|
1228 | * difficult question. Is a snapshot of a block that is changing better than |
---|
1229 | * nothing being written? We have tended to think we should hold changes for |
---|
1230 | * only a specific period of time even if still changing and get onto disk |
---|
1231 | * and letting the file system try and recover this position if it can. |
---|
1232 | */ |
---|
1233 | if (bd->state == RTEMS_BDBUF_STATE_ACCESS_CACHED |
---|
1234 | || bd->state == RTEMS_BDBUF_STATE_ACCESS_EMPTY) |
---|
1235 | bd->hold_timer = bdbuf_config.swap_block_hold; |
---|
1236 | |
---|
1237 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_MODIFIED); |
---|
1238 | rtems_chain_append_unprotected (&bdbuf_cache.modified, &bd->link); |
---|
1239 | |
---|
1240 | if (bd->waiters) |
---|
1241 | rtems_bdbuf_wake (&bdbuf_cache.access_waiters); |
---|
1242 | else if (rtems_bdbuf_has_buffer_waiters ()) |
---|
1243 | rtems_bdbuf_wake_swapper (); |
---|
1244 | } |
---|
1245 | |
---|
1246 | static void |
---|
1247 | rtems_bdbuf_add_to_lru_list_after_access (rtems_bdbuf_buffer *bd) |
---|
1248 | { |
---|
1249 | rtems_bdbuf_group_release (bd); |
---|
1250 | rtems_bdbuf_make_cached_and_add_to_lru_list (bd); |
---|
1251 | |
---|
1252 | if (bd->waiters) |
---|
1253 | rtems_bdbuf_wake (&bdbuf_cache.access_waiters); |
---|
1254 | else |
---|
1255 | rtems_bdbuf_wake (&bdbuf_cache.buffer_waiters); |
---|
1256 | } |
---|
1257 | |
---|
1258 | /** |
---|
1259 | * Compute the number of BDs per group for a given buffer size. |
---|
1260 | * |
---|
1261 | * @param size The buffer size. It can be any size and we scale up. |
---|
1262 | */ |
---|
1263 | static size_t |
---|
1264 | rtems_bdbuf_bds_per_group (size_t size) |
---|
1265 | { |
---|
1266 | size_t bufs_per_size; |
---|
1267 | size_t bds_per_size; |
---|
1268 | |
---|
1269 | if (size > bdbuf_config.buffer_max) |
---|
1270 | return 0; |
---|
1271 | |
---|
1272 | bufs_per_size = ((size - 1) / bdbuf_config.buffer_min) + 1; |
---|
1273 | |
---|
1274 | for (bds_per_size = 1; |
---|
1275 | bds_per_size < bufs_per_size; |
---|
1276 | bds_per_size <<= 1) |
---|
1277 | ; |
---|
1278 | |
---|
1279 | return bdbuf_cache.max_bds_per_group / bds_per_size; |
---|
1280 | } |
---|
1281 | |
---|
1282 | static void |
---|
1283 | rtems_bdbuf_discard_buffer_after_access (rtems_bdbuf_buffer *bd) |
---|
1284 | { |
---|
1285 | rtems_bdbuf_group_release (bd); |
---|
1286 | rtems_bdbuf_discard_buffer (bd); |
---|
1287 | |
---|
1288 | if (bd->waiters) |
---|
1289 | rtems_bdbuf_wake (&bdbuf_cache.access_waiters); |
---|
1290 | else |
---|
1291 | rtems_bdbuf_wake (&bdbuf_cache.buffer_waiters); |
---|
1292 | } |
---|
1293 | |
---|
1294 | /** |
---|
1295 | * Reallocate a group. The BDs currently allocated in the group are removed |
---|
1296 | * from the ALV tree and any lists then the new BD's are prepended to the ready |
---|
1297 | * list of the cache. |
---|
1298 | * |
---|
1299 | * @param group The group to reallocate. |
---|
1300 | * @param new_bds_per_group The new count of BDs per group. |
---|
1301 | * @return A buffer of this group. |
---|
1302 | */ |
---|
1303 | static rtems_bdbuf_buffer * |
---|
1304 | rtems_bdbuf_group_realloc (rtems_bdbuf_group* group, size_t new_bds_per_group) |
---|
1305 | { |
---|
1306 | rtems_bdbuf_buffer* bd; |
---|
1307 | size_t b; |
---|
1308 | size_t bufs_per_bd; |
---|
1309 | |
---|
1310 | if (rtems_bdbuf_tracer) |
---|
1311 | printf ("bdbuf:realloc: %tu: %zd -> %zd\n", |
---|
1312 | group - bdbuf_cache.groups, group->bds_per_group, |
---|
1313 | new_bds_per_group); |
---|
1314 | |
---|
1315 | bufs_per_bd = bdbuf_cache.max_bds_per_group / group->bds_per_group; |
---|
1316 | |
---|
1317 | for (b = 0, bd = group->bdbuf; |
---|
1318 | b < group->bds_per_group; |
---|
1319 | b++, bd += bufs_per_bd) |
---|
1320 | rtems_bdbuf_remove_from_tree_and_lru_list (bd); |
---|
1321 | |
---|
1322 | group->bds_per_group = new_bds_per_group; |
---|
1323 | bufs_per_bd = bdbuf_cache.max_bds_per_group / new_bds_per_group; |
---|
1324 | |
---|
1325 | for (b = 1, bd = group->bdbuf + bufs_per_bd; |
---|
1326 | b < group->bds_per_group; |
---|
1327 | b++, bd += bufs_per_bd) |
---|
1328 | rtems_bdbuf_make_free_and_add_to_lru_list (bd); |
---|
1329 | |
---|
1330 | if (b > 1) |
---|
1331 | rtems_bdbuf_wake (&bdbuf_cache.buffer_waiters); |
---|
1332 | |
---|
1333 | return group->bdbuf; |
---|
1334 | } |
---|
1335 | |
---|
1336 | static void |
---|
1337 | rtems_bdbuf_setup_empty_buffer (rtems_bdbuf_buffer *bd, |
---|
1338 | rtems_disk_device *dd, |
---|
1339 | rtems_blkdev_bnum block) |
---|
1340 | { |
---|
1341 | bd->dd = dd ; |
---|
1342 | bd->block = block; |
---|
1343 | bd->avl.left = NULL; |
---|
1344 | bd->avl.right = NULL; |
---|
1345 | bd->waiters = 0; |
---|
1346 | |
---|
1347 | if (rtems_bdbuf_avl_insert (&bdbuf_cache.tree, bd) != 0) |
---|
1348 | rtems_bdbuf_fatal (RTEMS_BDBUF_FATAL_RECYCLE); |
---|
1349 | |
---|
1350 | rtems_bdbuf_make_empty (bd); |
---|
1351 | } |
---|
1352 | |
---|
1353 | static rtems_bdbuf_buffer * |
---|
1354 | rtems_bdbuf_get_buffer_from_lru_list (rtems_disk_device *dd, |
---|
1355 | rtems_blkdev_bnum block) |
---|
1356 | { |
---|
1357 | rtems_chain_node *node = rtems_chain_first (&bdbuf_cache.lru); |
---|
1358 | |
---|
1359 | while (!rtems_chain_is_tail (&bdbuf_cache.lru, node)) |
---|
1360 | { |
---|
1361 | rtems_bdbuf_buffer *bd = (rtems_bdbuf_buffer *) node; |
---|
1362 | rtems_bdbuf_buffer *empty_bd = NULL; |
---|
1363 | |
---|
1364 | if (rtems_bdbuf_tracer) |
---|
1365 | printf ("bdbuf:next-bd: %tu (%td:%" PRId32 ") %zd -> %zd\n", |
---|
1366 | bd - bdbuf_cache.bds, |
---|
1367 | bd->group - bdbuf_cache.groups, bd->group->users, |
---|
1368 | bd->group->bds_per_group, dd->bds_per_group); |
---|
1369 | |
---|
1370 | /* |
---|
1371 | * If nobody waits for this BD, we may recycle it. |
---|
1372 | */ |
---|
1373 | if (bd->waiters == 0) |
---|
1374 | { |
---|
1375 | if (bd->group->bds_per_group == dd->bds_per_group) |
---|
1376 | { |
---|
1377 | rtems_bdbuf_remove_from_tree_and_lru_list (bd); |
---|
1378 | |
---|
1379 | empty_bd = bd; |
---|
1380 | } |
---|
1381 | else if (bd->group->users == 0) |
---|
1382 | empty_bd = rtems_bdbuf_group_realloc (bd->group, dd->bds_per_group); |
---|
1383 | } |
---|
1384 | |
---|
1385 | if (empty_bd != NULL) |
---|
1386 | { |
---|
1387 | rtems_bdbuf_setup_empty_buffer (empty_bd, dd, block); |
---|
1388 | |
---|
1389 | return empty_bd; |
---|
1390 | } |
---|
1391 | |
---|
1392 | node = rtems_chain_next (node); |
---|
1393 | } |
---|
1394 | |
---|
1395 | return NULL; |
---|
1396 | } |
---|
1397 | |
---|
1398 | static rtems_status_code |
---|
1399 | rtems_bdbuf_create_task( |
---|
1400 | rtems_name name, |
---|
1401 | rtems_task_priority priority, |
---|
1402 | rtems_task_priority default_priority, |
---|
1403 | rtems_id *id |
---|
1404 | ) |
---|
1405 | { |
---|
1406 | rtems_status_code sc; |
---|
1407 | size_t stack_size = bdbuf_config.task_stack_size ? |
---|
1408 | bdbuf_config.task_stack_size : RTEMS_BDBUF_TASK_STACK_SIZE_DEFAULT; |
---|
1409 | |
---|
1410 | priority = priority != 0 ? priority : default_priority; |
---|
1411 | |
---|
1412 | sc = rtems_task_create (name, |
---|
1413 | priority, |
---|
1414 | stack_size, |
---|
1415 | RTEMS_PREEMPT | RTEMS_NO_TIMESLICE | RTEMS_NO_ASR, |
---|
1416 | RTEMS_LOCAL | RTEMS_NO_FLOATING_POINT, |
---|
1417 | id); |
---|
1418 | |
---|
1419 | return sc; |
---|
1420 | } |
---|
1421 | |
---|
1422 | static rtems_bdbuf_swapout_transfer* |
---|
1423 | rtems_bdbuf_swapout_transfer_alloc (void) |
---|
1424 | { |
---|
1425 | /* |
---|
1426 | * @note chrisj The rtems_blkdev_request and the array at the end is a hack. |
---|
1427 | * I am disappointment at finding code like this in RTEMS. The request should |
---|
1428 | * have been a rtems_chain_control. Simple, fast and less storage as the node |
---|
1429 | * is already part of the buffer structure. |
---|
1430 | */ |
---|
1431 | size_t transfer_size = sizeof (rtems_bdbuf_swapout_transfer) |
---|
1432 | + (bdbuf_config.max_write_blocks * sizeof (rtems_blkdev_sg_buffer)); |
---|
1433 | return calloc (1, transfer_size); |
---|
1434 | } |
---|
1435 | |
---|
1436 | static void |
---|
1437 | rtems_bdbuf_transfer_done (rtems_blkdev_request* req, rtems_status_code status); |
---|
1438 | |
---|
1439 | static void |
---|
1440 | rtems_bdbuf_swapout_transfer_init (rtems_bdbuf_swapout_transfer* transfer, |
---|
1441 | rtems_id id) |
---|
1442 | { |
---|
1443 | rtems_chain_initialize_empty (&transfer->bds); |
---|
1444 | transfer->dd = BDBUF_INVALID_DEV; |
---|
1445 | transfer->syncing = false; |
---|
1446 | transfer->write_req.req = RTEMS_BLKDEV_REQ_WRITE; |
---|
1447 | transfer->write_req.done = rtems_bdbuf_transfer_done; |
---|
1448 | transfer->write_req.io_task = id; |
---|
1449 | } |
---|
1450 | |
---|
1451 | static size_t |
---|
1452 | rtems_bdbuf_swapout_worker_size (void) |
---|
1453 | { |
---|
1454 | return sizeof (rtems_bdbuf_swapout_worker) |
---|
1455 | + (bdbuf_config.max_write_blocks * sizeof (rtems_blkdev_sg_buffer)); |
---|
1456 | } |
---|
1457 | |
---|
1458 | static rtems_task |
---|
1459 | rtems_bdbuf_swapout_worker_task (rtems_task_argument arg); |
---|
1460 | |
---|
1461 | static rtems_status_code |
---|
1462 | rtems_bdbuf_swapout_workers_create (void) |
---|
1463 | { |
---|
1464 | rtems_status_code sc; |
---|
1465 | size_t w; |
---|
1466 | size_t worker_size; |
---|
1467 | char *worker_current; |
---|
1468 | |
---|
1469 | worker_size = rtems_bdbuf_swapout_worker_size (); |
---|
1470 | worker_current = calloc (1, bdbuf_config.swapout_workers * worker_size); |
---|
1471 | sc = worker_current != NULL ? RTEMS_SUCCESSFUL : RTEMS_NO_MEMORY; |
---|
1472 | |
---|
1473 | bdbuf_cache.swapout_workers = (rtems_bdbuf_swapout_worker *) worker_current; |
---|
1474 | |
---|
1475 | for (w = 0; |
---|
1476 | sc == RTEMS_SUCCESSFUL && w < bdbuf_config.swapout_workers; |
---|
1477 | w++, worker_current += worker_size) |
---|
1478 | { |
---|
1479 | rtems_bdbuf_swapout_worker *worker = (rtems_bdbuf_swapout_worker *) worker_current; |
---|
1480 | |
---|
1481 | sc = rtems_bdbuf_create_task (rtems_build_name('B', 'D', 'o', 'a' + w), |
---|
1482 | bdbuf_config.swapout_worker_priority, |
---|
1483 | RTEMS_BDBUF_SWAPOUT_WORKER_TASK_PRIORITY_DEFAULT, |
---|
1484 | &worker->id); |
---|
1485 | if (sc == RTEMS_SUCCESSFUL) |
---|
1486 | { |
---|
1487 | rtems_bdbuf_swapout_transfer_init (&worker->transfer, worker->id); |
---|
1488 | |
---|
1489 | rtems_chain_append_unprotected (&bdbuf_cache.swapout_free_workers, &worker->link); |
---|
1490 | worker->enabled = true; |
---|
1491 | |
---|
1492 | sc = rtems_task_start (worker->id, |
---|
1493 | rtems_bdbuf_swapout_worker_task, |
---|
1494 | (rtems_task_argument) worker); |
---|
1495 | } |
---|
1496 | } |
---|
1497 | |
---|
1498 | return sc; |
---|
1499 | } |
---|
1500 | |
---|
1501 | static size_t |
---|
1502 | rtems_bdbuf_read_request_size (uint32_t transfer_count) |
---|
1503 | { |
---|
1504 | return sizeof (rtems_blkdev_request) |
---|
1505 | + sizeof (rtems_blkdev_sg_buffer) * transfer_count; |
---|
1506 | } |
---|
1507 | |
---|
1508 | static rtems_status_code |
---|
1509 | rtems_bdbuf_do_init (void) |
---|
1510 | { |
---|
1511 | rtems_bdbuf_group* group; |
---|
1512 | rtems_bdbuf_buffer* bd; |
---|
1513 | uint8_t* buffer; |
---|
1514 | size_t b; |
---|
1515 | rtems_status_code sc; |
---|
1516 | |
---|
1517 | if (rtems_bdbuf_tracer) |
---|
1518 | printf ("bdbuf:init\n"); |
---|
1519 | |
---|
1520 | if (rtems_interrupt_is_in_progress()) |
---|
1521 | return RTEMS_CALLED_FROM_ISR; |
---|
1522 | |
---|
1523 | /* |
---|
1524 | * Check the configuration table values. |
---|
1525 | */ |
---|
1526 | |
---|
1527 | if ((bdbuf_config.buffer_max % bdbuf_config.buffer_min) != 0) |
---|
1528 | return RTEMS_INVALID_NUMBER; |
---|
1529 | |
---|
1530 | if (rtems_bdbuf_read_request_size (bdbuf_config.max_read_ahead_blocks) |
---|
1531 | > RTEMS_MINIMUM_STACK_SIZE / 8U) |
---|
1532 | return RTEMS_INVALID_NUMBER; |
---|
1533 | |
---|
1534 | bdbuf_cache.sync_device = BDBUF_INVALID_DEV; |
---|
1535 | |
---|
1536 | rtems_chain_initialize_empty (&bdbuf_cache.swapout_free_workers); |
---|
1537 | rtems_chain_initialize_empty (&bdbuf_cache.lru); |
---|
1538 | rtems_chain_initialize_empty (&bdbuf_cache.modified); |
---|
1539 | rtems_chain_initialize_empty (&bdbuf_cache.sync); |
---|
1540 | rtems_chain_initialize_empty (&bdbuf_cache.read_ahead_chain); |
---|
1541 | |
---|
1542 | /* |
---|
1543 | * Create the locks for the cache. |
---|
1544 | */ |
---|
1545 | |
---|
1546 | sc = rtems_bdbuf_lock_create (rtems_build_name ('B', 'D', 'C', 'l'), |
---|
1547 | &bdbuf_cache.lock); |
---|
1548 | if (sc != RTEMS_SUCCESSFUL) |
---|
1549 | goto error; |
---|
1550 | |
---|
1551 | rtems_bdbuf_lock_cache (); |
---|
1552 | |
---|
1553 | sc = rtems_bdbuf_lock_create (rtems_build_name ('B', 'D', 'C', 's'), |
---|
1554 | &bdbuf_cache.sync_lock); |
---|
1555 | if (sc != RTEMS_SUCCESSFUL) |
---|
1556 | goto error; |
---|
1557 | |
---|
1558 | sc = rtems_bdbuf_waiter_create (rtems_build_name ('B', 'D', 'C', 'a'), |
---|
1559 | &bdbuf_cache.access_waiters); |
---|
1560 | if (sc != RTEMS_SUCCESSFUL) |
---|
1561 | goto error; |
---|
1562 | |
---|
1563 | sc = rtems_bdbuf_waiter_create (rtems_build_name ('B', 'D', 'C', 't'), |
---|
1564 | &bdbuf_cache.transfer_waiters); |
---|
1565 | if (sc != RTEMS_SUCCESSFUL) |
---|
1566 | goto error; |
---|
1567 | |
---|
1568 | sc = rtems_bdbuf_waiter_create (rtems_build_name ('B', 'D', 'C', 'b'), |
---|
1569 | &bdbuf_cache.buffer_waiters); |
---|
1570 | if (sc != RTEMS_SUCCESSFUL) |
---|
1571 | goto error; |
---|
1572 | |
---|
1573 | /* |
---|
1574 | * Compute the various number of elements in the cache. |
---|
1575 | */ |
---|
1576 | bdbuf_cache.buffer_min_count = |
---|
1577 | bdbuf_config.size / bdbuf_config.buffer_min; |
---|
1578 | bdbuf_cache.max_bds_per_group = |
---|
1579 | bdbuf_config.buffer_max / bdbuf_config.buffer_min; |
---|
1580 | bdbuf_cache.group_count = |
---|
1581 | bdbuf_cache.buffer_min_count / bdbuf_cache.max_bds_per_group; |
---|
1582 | |
---|
1583 | /* |
---|
1584 | * Allocate the memory for the buffer descriptors. |
---|
1585 | */ |
---|
1586 | bdbuf_cache.bds = calloc (sizeof (rtems_bdbuf_buffer), |
---|
1587 | bdbuf_cache.buffer_min_count); |
---|
1588 | if (!bdbuf_cache.bds) |
---|
1589 | goto error; |
---|
1590 | |
---|
1591 | /* |
---|
1592 | * Allocate the memory for the buffer descriptors. |
---|
1593 | */ |
---|
1594 | bdbuf_cache.groups = calloc (sizeof (rtems_bdbuf_group), |
---|
1595 | bdbuf_cache.group_count); |
---|
1596 | if (!bdbuf_cache.groups) |
---|
1597 | goto error; |
---|
1598 | |
---|
1599 | /* |
---|
1600 | * Allocate memory for buffer memory. The buffer memory will be cache |
---|
1601 | * aligned. It is possible to free the memory allocated by |
---|
1602 | * rtems_cache_aligned_malloc() with free(). |
---|
1603 | */ |
---|
1604 | bdbuf_cache.buffers = rtems_cache_aligned_malloc(bdbuf_cache.buffer_min_count |
---|
1605 | * bdbuf_config.buffer_min); |
---|
1606 | if (bdbuf_cache.buffers == NULL) |
---|
1607 | goto error; |
---|
1608 | |
---|
1609 | /* |
---|
1610 | * The cache is empty after opening so we need to add all the buffers to it |
---|
1611 | * and initialise the groups. |
---|
1612 | */ |
---|
1613 | for (b = 0, group = bdbuf_cache.groups, |
---|
1614 | bd = bdbuf_cache.bds, buffer = bdbuf_cache.buffers; |
---|
1615 | b < bdbuf_cache.buffer_min_count; |
---|
1616 | b++, bd++, buffer += bdbuf_config.buffer_min) |
---|
1617 | { |
---|
1618 | bd->dd = BDBUF_INVALID_DEV; |
---|
1619 | bd->group = group; |
---|
1620 | bd->buffer = buffer; |
---|
1621 | |
---|
1622 | rtems_chain_append_unprotected (&bdbuf_cache.lru, &bd->link); |
---|
1623 | |
---|
1624 | if ((b % bdbuf_cache.max_bds_per_group) == |
---|
1625 | (bdbuf_cache.max_bds_per_group - 1)) |
---|
1626 | group++; |
---|
1627 | } |
---|
1628 | |
---|
1629 | for (b = 0, |
---|
1630 | group = bdbuf_cache.groups, |
---|
1631 | bd = bdbuf_cache.bds; |
---|
1632 | b < bdbuf_cache.group_count; |
---|
1633 | b++, |
---|
1634 | group++, |
---|
1635 | bd += bdbuf_cache.max_bds_per_group) |
---|
1636 | { |
---|
1637 | group->bds_per_group = bdbuf_cache.max_bds_per_group; |
---|
1638 | group->bdbuf = bd; |
---|
1639 | } |
---|
1640 | |
---|
1641 | /* |
---|
1642 | * Create and start swapout task. |
---|
1643 | */ |
---|
1644 | |
---|
1645 | bdbuf_cache.swapout_transfer = rtems_bdbuf_swapout_transfer_alloc (); |
---|
1646 | if (!bdbuf_cache.swapout_transfer) |
---|
1647 | goto error; |
---|
1648 | |
---|
1649 | bdbuf_cache.swapout_enabled = true; |
---|
1650 | |
---|
1651 | sc = rtems_bdbuf_create_task (rtems_build_name('B', 'S', 'W', 'P'), |
---|
1652 | bdbuf_config.swapout_priority, |
---|
1653 | RTEMS_BDBUF_SWAPOUT_TASK_PRIORITY_DEFAULT, |
---|
1654 | &bdbuf_cache.swapout); |
---|
1655 | if (sc != RTEMS_SUCCESSFUL) |
---|
1656 | goto error; |
---|
1657 | |
---|
1658 | rtems_bdbuf_swapout_transfer_init (bdbuf_cache.swapout_transfer, bdbuf_cache.swapout); |
---|
1659 | |
---|
1660 | sc = rtems_task_start (bdbuf_cache.swapout, |
---|
1661 | rtems_bdbuf_swapout_task, |
---|
1662 | (rtems_task_argument) bdbuf_cache.swapout_transfer); |
---|
1663 | if (sc != RTEMS_SUCCESSFUL) |
---|
1664 | goto error; |
---|
1665 | |
---|
1666 | if (bdbuf_config.swapout_workers > 0) |
---|
1667 | { |
---|
1668 | sc = rtems_bdbuf_swapout_workers_create (); |
---|
1669 | if (sc != RTEMS_SUCCESSFUL) |
---|
1670 | goto error; |
---|
1671 | } |
---|
1672 | |
---|
1673 | if (bdbuf_config.max_read_ahead_blocks > 0) |
---|
1674 | { |
---|
1675 | bdbuf_cache.read_ahead_enabled = true; |
---|
1676 | sc = rtems_bdbuf_create_task (rtems_build_name('B', 'R', 'D', 'A'), |
---|
1677 | bdbuf_config.read_ahead_priority, |
---|
1678 | RTEMS_BDBUF_READ_AHEAD_TASK_PRIORITY_DEFAULT, |
---|
1679 | &bdbuf_cache.read_ahead_task); |
---|
1680 | if (sc != RTEMS_SUCCESSFUL) |
---|
1681 | goto error; |
---|
1682 | |
---|
1683 | sc = rtems_task_start (bdbuf_cache.read_ahead_task, |
---|
1684 | rtems_bdbuf_read_ahead_task, |
---|
1685 | 0); |
---|
1686 | if (sc != RTEMS_SUCCESSFUL) |
---|
1687 | goto error; |
---|
1688 | } |
---|
1689 | |
---|
1690 | rtems_bdbuf_unlock_cache (); |
---|
1691 | |
---|
1692 | return RTEMS_SUCCESSFUL; |
---|
1693 | |
---|
1694 | error: |
---|
1695 | |
---|
1696 | if (bdbuf_cache.read_ahead_task != 0) |
---|
1697 | rtems_task_delete (bdbuf_cache.read_ahead_task); |
---|
1698 | |
---|
1699 | if (bdbuf_cache.swapout != 0) |
---|
1700 | rtems_task_delete (bdbuf_cache.swapout); |
---|
1701 | |
---|
1702 | if (bdbuf_cache.swapout_workers) |
---|
1703 | { |
---|
1704 | char *worker_current = (char *) bdbuf_cache.swapout_workers; |
---|
1705 | size_t worker_size = rtems_bdbuf_swapout_worker_size (); |
---|
1706 | size_t w; |
---|
1707 | |
---|
1708 | for (w = 0; |
---|
1709 | w < bdbuf_config.swapout_workers; |
---|
1710 | w++, worker_current += worker_size) |
---|
1711 | { |
---|
1712 | rtems_bdbuf_swapout_worker *worker = (rtems_bdbuf_swapout_worker *) worker_current; |
---|
1713 | |
---|
1714 | if (worker->id != 0) { |
---|
1715 | rtems_task_delete (worker->id); |
---|
1716 | } |
---|
1717 | } |
---|
1718 | } |
---|
1719 | |
---|
1720 | free (bdbuf_cache.buffers); |
---|
1721 | free (bdbuf_cache.groups); |
---|
1722 | free (bdbuf_cache.bds); |
---|
1723 | free (bdbuf_cache.swapout_transfer); |
---|
1724 | free (bdbuf_cache.swapout_workers); |
---|
1725 | |
---|
1726 | rtems_bdbuf_waiter_delete (&bdbuf_cache.buffer_waiters); |
---|
1727 | rtems_bdbuf_waiter_delete (&bdbuf_cache.access_waiters); |
---|
1728 | rtems_bdbuf_waiter_delete (&bdbuf_cache.transfer_waiters); |
---|
1729 | rtems_bdbuf_lock_delete (&bdbuf_cache.sync_lock); |
---|
1730 | |
---|
1731 | if (bdbuf_cache.lock != 0) |
---|
1732 | { |
---|
1733 | rtems_bdbuf_unlock_cache (); |
---|
1734 | rtems_bdbuf_lock_delete (&bdbuf_cache.lock); |
---|
1735 | } |
---|
1736 | |
---|
1737 | return RTEMS_UNSATISFIED; |
---|
1738 | } |
---|
1739 | |
---|
1740 | static void |
---|
1741 | rtems_bdbuf_init_once (void) |
---|
1742 | { |
---|
1743 | bdbuf_cache.init_status = rtems_bdbuf_do_init(); |
---|
1744 | } |
---|
1745 | |
---|
1746 | rtems_status_code |
---|
1747 | rtems_bdbuf_init (void) |
---|
1748 | { |
---|
1749 | int eno = pthread_once (&rtems_bdbuf_once_state, rtems_bdbuf_init_once); |
---|
1750 | |
---|
1751 | if (eno != 0) |
---|
1752 | rtems_bdbuf_fatal (RTEMS_BDBUF_FATAL_ONCE); |
---|
1753 | |
---|
1754 | return bdbuf_cache.init_status; |
---|
1755 | } |
---|
1756 | |
---|
1757 | static void |
---|
1758 | rtems_bdbuf_wait_for_event (rtems_event_set event) |
---|
1759 | { |
---|
1760 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
1761 | rtems_event_set out = 0; |
---|
1762 | |
---|
1763 | sc = rtems_event_receive (event, |
---|
1764 | RTEMS_EVENT_ALL | RTEMS_WAIT, |
---|
1765 | RTEMS_NO_TIMEOUT, |
---|
1766 | &out); |
---|
1767 | |
---|
1768 | if (sc != RTEMS_SUCCESSFUL || out != event) |
---|
1769 | rtems_bdbuf_fatal (RTEMS_BDBUF_FATAL_WAIT_EVNT); |
---|
1770 | } |
---|
1771 | |
---|
1772 | static void |
---|
1773 | rtems_bdbuf_wait_for_transient_event (void) |
---|
1774 | { |
---|
1775 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
1776 | |
---|
1777 | sc = rtems_event_transient_receive (RTEMS_WAIT, RTEMS_NO_TIMEOUT); |
---|
1778 | if (sc != RTEMS_SUCCESSFUL) |
---|
1779 | rtems_bdbuf_fatal (RTEMS_BDBUF_FATAL_WAIT_TRANS_EVNT); |
---|
1780 | } |
---|
1781 | |
---|
1782 | static void |
---|
1783 | rtems_bdbuf_wait_for_access (rtems_bdbuf_buffer *bd) |
---|
1784 | { |
---|
1785 | while (true) |
---|
1786 | { |
---|
1787 | switch (bd->state) |
---|
1788 | { |
---|
1789 | case RTEMS_BDBUF_STATE_MODIFIED: |
---|
1790 | rtems_bdbuf_group_release (bd); |
---|
1791 | /* Fall through */ |
---|
1792 | case RTEMS_BDBUF_STATE_CACHED: |
---|
1793 | rtems_chain_extract_unprotected (&bd->link); |
---|
1794 | /* Fall through */ |
---|
1795 | case RTEMS_BDBUF_STATE_EMPTY: |
---|
1796 | return; |
---|
1797 | case RTEMS_BDBUF_STATE_ACCESS_CACHED: |
---|
1798 | case RTEMS_BDBUF_STATE_ACCESS_EMPTY: |
---|
1799 | case RTEMS_BDBUF_STATE_ACCESS_MODIFIED: |
---|
1800 | case RTEMS_BDBUF_STATE_ACCESS_PURGED: |
---|
1801 | rtems_bdbuf_wait (bd, &bdbuf_cache.access_waiters); |
---|
1802 | break; |
---|
1803 | case RTEMS_BDBUF_STATE_SYNC: |
---|
1804 | case RTEMS_BDBUF_STATE_TRANSFER: |
---|
1805 | case RTEMS_BDBUF_STATE_TRANSFER_PURGED: |
---|
1806 | rtems_bdbuf_wait (bd, &bdbuf_cache.transfer_waiters); |
---|
1807 | break; |
---|
1808 | default: |
---|
1809 | rtems_bdbuf_fatal_with_state (bd->state, RTEMS_BDBUF_FATAL_STATE_7); |
---|
1810 | } |
---|
1811 | } |
---|
1812 | } |
---|
1813 | |
---|
1814 | static void |
---|
1815 | rtems_bdbuf_request_sync_for_modified_buffer (rtems_bdbuf_buffer *bd) |
---|
1816 | { |
---|
1817 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_SYNC); |
---|
1818 | rtems_chain_extract_unprotected (&bd->link); |
---|
1819 | rtems_chain_append_unprotected (&bdbuf_cache.sync, &bd->link); |
---|
1820 | rtems_bdbuf_wake_swapper (); |
---|
1821 | } |
---|
1822 | |
---|
1823 | /** |
---|
1824 | * @brief Waits until the buffer is ready for recycling. |
---|
1825 | * |
---|
1826 | * @retval @c true Buffer is valid and may be recycled. |
---|
1827 | * @retval @c false Buffer is invalid and has to searched again. |
---|
1828 | */ |
---|
1829 | static bool |
---|
1830 | rtems_bdbuf_wait_for_recycle (rtems_bdbuf_buffer *bd) |
---|
1831 | { |
---|
1832 | while (true) |
---|
1833 | { |
---|
1834 | switch (bd->state) |
---|
1835 | { |
---|
1836 | case RTEMS_BDBUF_STATE_FREE: |
---|
1837 | return true; |
---|
1838 | case RTEMS_BDBUF_STATE_MODIFIED: |
---|
1839 | rtems_bdbuf_request_sync_for_modified_buffer (bd); |
---|
1840 | break; |
---|
1841 | case RTEMS_BDBUF_STATE_CACHED: |
---|
1842 | case RTEMS_BDBUF_STATE_EMPTY: |
---|
1843 | if (bd->waiters == 0) |
---|
1844 | return true; |
---|
1845 | else |
---|
1846 | { |
---|
1847 | /* |
---|
1848 | * It is essential that we wait here without a special wait count and |
---|
1849 | * without the group in use. Otherwise we could trigger a wait ping |
---|
1850 | * pong with another recycle waiter. The state of the buffer is |
---|
1851 | * arbitrary afterwards. |
---|
1852 | */ |
---|
1853 | rtems_bdbuf_anonymous_wait (&bdbuf_cache.buffer_waiters); |
---|
1854 | return false; |
---|
1855 | } |
---|
1856 | case RTEMS_BDBUF_STATE_ACCESS_CACHED: |
---|
1857 | case RTEMS_BDBUF_STATE_ACCESS_EMPTY: |
---|
1858 | case RTEMS_BDBUF_STATE_ACCESS_MODIFIED: |
---|
1859 | case RTEMS_BDBUF_STATE_ACCESS_PURGED: |
---|
1860 | rtems_bdbuf_wait (bd, &bdbuf_cache.access_waiters); |
---|
1861 | break; |
---|
1862 | case RTEMS_BDBUF_STATE_SYNC: |
---|
1863 | case RTEMS_BDBUF_STATE_TRANSFER: |
---|
1864 | case RTEMS_BDBUF_STATE_TRANSFER_PURGED: |
---|
1865 | rtems_bdbuf_wait (bd, &bdbuf_cache.transfer_waiters); |
---|
1866 | break; |
---|
1867 | default: |
---|
1868 | rtems_bdbuf_fatal_with_state (bd->state, RTEMS_BDBUF_FATAL_STATE_8); |
---|
1869 | } |
---|
1870 | } |
---|
1871 | } |
---|
1872 | |
---|
1873 | static void |
---|
1874 | rtems_bdbuf_wait_for_sync_done (rtems_bdbuf_buffer *bd) |
---|
1875 | { |
---|
1876 | while (true) |
---|
1877 | { |
---|
1878 | switch (bd->state) |
---|
1879 | { |
---|
1880 | case RTEMS_BDBUF_STATE_CACHED: |
---|
1881 | case RTEMS_BDBUF_STATE_EMPTY: |
---|
1882 | case RTEMS_BDBUF_STATE_MODIFIED: |
---|
1883 | case RTEMS_BDBUF_STATE_ACCESS_CACHED: |
---|
1884 | case RTEMS_BDBUF_STATE_ACCESS_EMPTY: |
---|
1885 | case RTEMS_BDBUF_STATE_ACCESS_MODIFIED: |
---|
1886 | case RTEMS_BDBUF_STATE_ACCESS_PURGED: |
---|
1887 | return; |
---|
1888 | case RTEMS_BDBUF_STATE_SYNC: |
---|
1889 | case RTEMS_BDBUF_STATE_TRANSFER: |
---|
1890 | case RTEMS_BDBUF_STATE_TRANSFER_PURGED: |
---|
1891 | rtems_bdbuf_wait (bd, &bdbuf_cache.transfer_waiters); |
---|
1892 | break; |
---|
1893 | default: |
---|
1894 | rtems_bdbuf_fatal_with_state (bd->state, RTEMS_BDBUF_FATAL_STATE_9); |
---|
1895 | } |
---|
1896 | } |
---|
1897 | } |
---|
1898 | |
---|
1899 | static void |
---|
1900 | rtems_bdbuf_wait_for_buffer (void) |
---|
1901 | { |
---|
1902 | if (!rtems_chain_is_empty (&bdbuf_cache.modified)) |
---|
1903 | rtems_bdbuf_wake_swapper (); |
---|
1904 | |
---|
1905 | rtems_bdbuf_anonymous_wait (&bdbuf_cache.buffer_waiters); |
---|
1906 | } |
---|
1907 | |
---|
1908 | static void |
---|
1909 | rtems_bdbuf_sync_after_access (rtems_bdbuf_buffer *bd) |
---|
1910 | { |
---|
1911 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_SYNC); |
---|
1912 | |
---|
1913 | rtems_chain_append_unprotected (&bdbuf_cache.sync, &bd->link); |
---|
1914 | |
---|
1915 | if (bd->waiters) |
---|
1916 | rtems_bdbuf_wake (&bdbuf_cache.access_waiters); |
---|
1917 | |
---|
1918 | rtems_bdbuf_wake_swapper (); |
---|
1919 | rtems_bdbuf_wait_for_sync_done (bd); |
---|
1920 | |
---|
1921 | /* |
---|
1922 | * We may have created a cached or empty buffer which may be recycled. |
---|
1923 | */ |
---|
1924 | if (bd->waiters == 0 |
---|
1925 | && (bd->state == RTEMS_BDBUF_STATE_CACHED |
---|
1926 | || bd->state == RTEMS_BDBUF_STATE_EMPTY)) |
---|
1927 | { |
---|
1928 | if (bd->state == RTEMS_BDBUF_STATE_EMPTY) |
---|
1929 | { |
---|
1930 | rtems_bdbuf_remove_from_tree (bd); |
---|
1931 | rtems_bdbuf_make_free_and_add_to_lru_list (bd); |
---|
1932 | } |
---|
1933 | rtems_bdbuf_wake (&bdbuf_cache.buffer_waiters); |
---|
1934 | } |
---|
1935 | } |
---|
1936 | |
---|
1937 | static rtems_bdbuf_buffer * |
---|
1938 | rtems_bdbuf_get_buffer_for_read_ahead (rtems_disk_device *dd, |
---|
1939 | rtems_blkdev_bnum block) |
---|
1940 | { |
---|
1941 | rtems_bdbuf_buffer *bd = NULL; |
---|
1942 | |
---|
1943 | bd = rtems_bdbuf_avl_search (&bdbuf_cache.tree, dd, block); |
---|
1944 | |
---|
1945 | if (bd == NULL) |
---|
1946 | { |
---|
1947 | bd = rtems_bdbuf_get_buffer_from_lru_list (dd, block); |
---|
1948 | |
---|
1949 | if (bd != NULL) |
---|
1950 | rtems_bdbuf_group_obtain (bd); |
---|
1951 | } |
---|
1952 | else |
---|
1953 | /* |
---|
1954 | * The buffer is in the cache. So it is already available or in use, and |
---|
1955 | * thus no need for a read ahead. |
---|
1956 | */ |
---|
1957 | bd = NULL; |
---|
1958 | |
---|
1959 | return bd; |
---|
1960 | } |
---|
1961 | |
---|
1962 | static rtems_bdbuf_buffer * |
---|
1963 | rtems_bdbuf_get_buffer_for_access (rtems_disk_device *dd, |
---|
1964 | rtems_blkdev_bnum block) |
---|
1965 | { |
---|
1966 | rtems_bdbuf_buffer *bd = NULL; |
---|
1967 | |
---|
1968 | do |
---|
1969 | { |
---|
1970 | bd = rtems_bdbuf_avl_search (&bdbuf_cache.tree, dd, block); |
---|
1971 | |
---|
1972 | if (bd != NULL) |
---|
1973 | { |
---|
1974 | if (bd->group->bds_per_group != dd->bds_per_group) |
---|
1975 | { |
---|
1976 | if (rtems_bdbuf_wait_for_recycle (bd)) |
---|
1977 | { |
---|
1978 | rtems_bdbuf_remove_from_tree_and_lru_list (bd); |
---|
1979 | rtems_bdbuf_make_free_and_add_to_lru_list (bd); |
---|
1980 | rtems_bdbuf_wake (&bdbuf_cache.buffer_waiters); |
---|
1981 | } |
---|
1982 | bd = NULL; |
---|
1983 | } |
---|
1984 | } |
---|
1985 | else |
---|
1986 | { |
---|
1987 | bd = rtems_bdbuf_get_buffer_from_lru_list (dd, block); |
---|
1988 | |
---|
1989 | if (bd == NULL) |
---|
1990 | rtems_bdbuf_wait_for_buffer (); |
---|
1991 | } |
---|
1992 | } |
---|
1993 | while (bd == NULL); |
---|
1994 | |
---|
1995 | rtems_bdbuf_wait_for_access (bd); |
---|
1996 | rtems_bdbuf_group_obtain (bd); |
---|
1997 | |
---|
1998 | return bd; |
---|
1999 | } |
---|
2000 | |
---|
2001 | static rtems_status_code |
---|
2002 | rtems_bdbuf_get_media_block (const rtems_disk_device *dd, |
---|
2003 | rtems_blkdev_bnum block, |
---|
2004 | rtems_blkdev_bnum *media_block_ptr) |
---|
2005 | { |
---|
2006 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
2007 | |
---|
2008 | if (block < dd->block_count) |
---|
2009 | { |
---|
2010 | /* |
---|
2011 | * Compute the media block number. Drivers work with media block number not |
---|
2012 | * the block number a BD may have as this depends on the block size set by |
---|
2013 | * the user. |
---|
2014 | */ |
---|
2015 | *media_block_ptr = rtems_bdbuf_media_block (dd, block) + dd->start; |
---|
2016 | } |
---|
2017 | else |
---|
2018 | { |
---|
2019 | sc = RTEMS_INVALID_ID; |
---|
2020 | } |
---|
2021 | |
---|
2022 | return sc; |
---|
2023 | } |
---|
2024 | |
---|
2025 | rtems_status_code |
---|
2026 | rtems_bdbuf_get (rtems_disk_device *dd, |
---|
2027 | rtems_blkdev_bnum block, |
---|
2028 | rtems_bdbuf_buffer **bd_ptr) |
---|
2029 | { |
---|
2030 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
2031 | rtems_bdbuf_buffer *bd = NULL; |
---|
2032 | rtems_blkdev_bnum media_block; |
---|
2033 | |
---|
2034 | rtems_bdbuf_lock_cache (); |
---|
2035 | |
---|
2036 | sc = rtems_bdbuf_get_media_block (dd, block, &media_block); |
---|
2037 | if (sc == RTEMS_SUCCESSFUL) |
---|
2038 | { |
---|
2039 | /* |
---|
2040 | * Print the block index relative to the physical disk. |
---|
2041 | */ |
---|
2042 | if (rtems_bdbuf_tracer) |
---|
2043 | printf ("bdbuf:get: %" PRIu32 " (%" PRIu32 ") (dev = %08x)\n", |
---|
2044 | media_block, block, (unsigned) dd->dev); |
---|
2045 | |
---|
2046 | bd = rtems_bdbuf_get_buffer_for_access (dd, media_block); |
---|
2047 | |
---|
2048 | switch (bd->state) |
---|
2049 | { |
---|
2050 | case RTEMS_BDBUF_STATE_CACHED: |
---|
2051 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_ACCESS_CACHED); |
---|
2052 | break; |
---|
2053 | case RTEMS_BDBUF_STATE_EMPTY: |
---|
2054 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_ACCESS_EMPTY); |
---|
2055 | break; |
---|
2056 | case RTEMS_BDBUF_STATE_MODIFIED: |
---|
2057 | /* |
---|
2058 | * To get a modified buffer could be considered a bug in the caller |
---|
2059 | * because you should not be getting an already modified buffer but |
---|
2060 | * user may have modified a byte in a block then decided to seek the |
---|
2061 | * start and write the whole block and the file system will have no |
---|
2062 | * record of this so just gets the block to fill. |
---|
2063 | */ |
---|
2064 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_ACCESS_MODIFIED); |
---|
2065 | break; |
---|
2066 | default: |
---|
2067 | rtems_bdbuf_fatal_with_state (bd->state, RTEMS_BDBUF_FATAL_STATE_2); |
---|
2068 | break; |
---|
2069 | } |
---|
2070 | |
---|
2071 | if (rtems_bdbuf_tracer) |
---|
2072 | { |
---|
2073 | rtems_bdbuf_show_users ("get", bd); |
---|
2074 | rtems_bdbuf_show_usage (); |
---|
2075 | } |
---|
2076 | } |
---|
2077 | |
---|
2078 | rtems_bdbuf_unlock_cache (); |
---|
2079 | |
---|
2080 | *bd_ptr = bd; |
---|
2081 | |
---|
2082 | return sc; |
---|
2083 | } |
---|
2084 | |
---|
2085 | /** |
---|
2086 | * Call back handler called by the low level driver when the transfer has |
---|
2087 | * completed. This function may be invoked from interrupt handler. |
---|
2088 | * |
---|
2089 | * @param arg Arbitrary argument specified in block device request |
---|
2090 | * structure (in this case - pointer to the appropriate |
---|
2091 | * block device request structure). |
---|
2092 | * @param status I/O completion status |
---|
2093 | */ |
---|
2094 | static void |
---|
2095 | rtems_bdbuf_transfer_done (rtems_blkdev_request* req, rtems_status_code status) |
---|
2096 | { |
---|
2097 | req->status = status; |
---|
2098 | |
---|
2099 | rtems_event_transient_send (req->io_task); |
---|
2100 | } |
---|
2101 | |
---|
2102 | static rtems_status_code |
---|
2103 | rtems_bdbuf_execute_transfer_request (rtems_disk_device *dd, |
---|
2104 | rtems_blkdev_request *req, |
---|
2105 | bool cache_locked) |
---|
2106 | { |
---|
2107 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
2108 | uint32_t transfer_index = 0; |
---|
2109 | bool wake_transfer_waiters = false; |
---|
2110 | bool wake_buffer_waiters = false; |
---|
2111 | |
---|
2112 | if (cache_locked) |
---|
2113 | rtems_bdbuf_unlock_cache (); |
---|
2114 | |
---|
2115 | /* The return value will be ignored for transfer requests */ |
---|
2116 | dd->ioctl (dd->phys_dev, RTEMS_BLKIO_REQUEST, req); |
---|
2117 | |
---|
2118 | /* Wait for transfer request completion */ |
---|
2119 | rtems_bdbuf_wait_for_transient_event (); |
---|
2120 | sc = req->status; |
---|
2121 | |
---|
2122 | rtems_bdbuf_lock_cache (); |
---|
2123 | |
---|
2124 | /* Statistics */ |
---|
2125 | if (req->req == RTEMS_BLKDEV_REQ_READ) |
---|
2126 | { |
---|
2127 | dd->stats.read_blocks += req->bufnum; |
---|
2128 | if (sc != RTEMS_SUCCESSFUL) |
---|
2129 | ++dd->stats.read_errors; |
---|
2130 | } |
---|
2131 | else |
---|
2132 | { |
---|
2133 | dd->stats.write_blocks += req->bufnum; |
---|
2134 | ++dd->stats.write_transfers; |
---|
2135 | if (sc != RTEMS_SUCCESSFUL) |
---|
2136 | ++dd->stats.write_errors; |
---|
2137 | } |
---|
2138 | |
---|
2139 | for (transfer_index = 0; transfer_index < req->bufnum; ++transfer_index) |
---|
2140 | { |
---|
2141 | rtems_bdbuf_buffer *bd = req->bufs [transfer_index].user; |
---|
2142 | bool waiters = bd->waiters; |
---|
2143 | |
---|
2144 | if (waiters) |
---|
2145 | wake_transfer_waiters = true; |
---|
2146 | else |
---|
2147 | wake_buffer_waiters = true; |
---|
2148 | |
---|
2149 | rtems_bdbuf_group_release (bd); |
---|
2150 | |
---|
2151 | if (sc == RTEMS_SUCCESSFUL && bd->state == RTEMS_BDBUF_STATE_TRANSFER) |
---|
2152 | rtems_bdbuf_make_cached_and_add_to_lru_list (bd); |
---|
2153 | else |
---|
2154 | rtems_bdbuf_discard_buffer (bd); |
---|
2155 | |
---|
2156 | if (rtems_bdbuf_tracer) |
---|
2157 | rtems_bdbuf_show_users ("transfer", bd); |
---|
2158 | } |
---|
2159 | |
---|
2160 | if (wake_transfer_waiters) |
---|
2161 | rtems_bdbuf_wake (&bdbuf_cache.transfer_waiters); |
---|
2162 | |
---|
2163 | if (wake_buffer_waiters) |
---|
2164 | rtems_bdbuf_wake (&bdbuf_cache.buffer_waiters); |
---|
2165 | |
---|
2166 | if (!cache_locked) |
---|
2167 | rtems_bdbuf_unlock_cache (); |
---|
2168 | |
---|
2169 | if (sc == RTEMS_SUCCESSFUL || sc == RTEMS_UNSATISFIED) |
---|
2170 | return sc; |
---|
2171 | else |
---|
2172 | return RTEMS_IO_ERROR; |
---|
2173 | } |
---|
2174 | |
---|
2175 | static rtems_status_code |
---|
2176 | rtems_bdbuf_execute_read_request (rtems_disk_device *dd, |
---|
2177 | rtems_bdbuf_buffer *bd, |
---|
2178 | uint32_t transfer_count) |
---|
2179 | { |
---|
2180 | rtems_blkdev_request *req = NULL; |
---|
2181 | rtems_blkdev_bnum media_block = bd->block; |
---|
2182 | uint32_t media_blocks_per_block = dd->media_blocks_per_block; |
---|
2183 | uint32_t block_size = dd->block_size; |
---|
2184 | uint32_t transfer_index = 1; |
---|
2185 | |
---|
2186 | /* |
---|
2187 | * TODO: This type of request structure is wrong and should be removed. |
---|
2188 | */ |
---|
2189 | #define bdbuf_alloc(size) __builtin_alloca (size) |
---|
2190 | |
---|
2191 | req = bdbuf_alloc (rtems_bdbuf_read_request_size (transfer_count)); |
---|
2192 | |
---|
2193 | req->req = RTEMS_BLKDEV_REQ_READ; |
---|
2194 | req->done = rtems_bdbuf_transfer_done; |
---|
2195 | req->io_task = rtems_task_self (); |
---|
2196 | req->bufnum = 0; |
---|
2197 | |
---|
2198 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_TRANSFER); |
---|
2199 | |
---|
2200 | req->bufs [0].user = bd; |
---|
2201 | req->bufs [0].block = media_block; |
---|
2202 | req->bufs [0].length = block_size; |
---|
2203 | req->bufs [0].buffer = bd->buffer; |
---|
2204 | |
---|
2205 | if (rtems_bdbuf_tracer) |
---|
2206 | rtems_bdbuf_show_users ("read", bd); |
---|
2207 | |
---|
2208 | while (transfer_index < transfer_count) |
---|
2209 | { |
---|
2210 | media_block += media_blocks_per_block; |
---|
2211 | |
---|
2212 | bd = rtems_bdbuf_get_buffer_for_read_ahead (dd, media_block); |
---|
2213 | |
---|
2214 | if (bd == NULL) |
---|
2215 | break; |
---|
2216 | |
---|
2217 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_TRANSFER); |
---|
2218 | |
---|
2219 | req->bufs [transfer_index].user = bd; |
---|
2220 | req->bufs [transfer_index].block = media_block; |
---|
2221 | req->bufs [transfer_index].length = block_size; |
---|
2222 | req->bufs [transfer_index].buffer = bd->buffer; |
---|
2223 | |
---|
2224 | if (rtems_bdbuf_tracer) |
---|
2225 | rtems_bdbuf_show_users ("read", bd); |
---|
2226 | |
---|
2227 | ++transfer_index; |
---|
2228 | } |
---|
2229 | |
---|
2230 | req->bufnum = transfer_index; |
---|
2231 | |
---|
2232 | return rtems_bdbuf_execute_transfer_request (dd, req, true); |
---|
2233 | } |
---|
2234 | |
---|
2235 | static bool |
---|
2236 | rtems_bdbuf_is_read_ahead_active (const rtems_disk_device *dd) |
---|
2237 | { |
---|
2238 | return !rtems_chain_is_node_off_chain (&dd->read_ahead.node); |
---|
2239 | } |
---|
2240 | |
---|
2241 | static void |
---|
2242 | rtems_bdbuf_read_ahead_cancel (rtems_disk_device *dd) |
---|
2243 | { |
---|
2244 | if (rtems_bdbuf_is_read_ahead_active (dd)) |
---|
2245 | { |
---|
2246 | rtems_chain_extract_unprotected (&dd->read_ahead.node); |
---|
2247 | rtems_chain_set_off_chain (&dd->read_ahead.node); |
---|
2248 | } |
---|
2249 | } |
---|
2250 | |
---|
2251 | static void |
---|
2252 | rtems_bdbuf_read_ahead_reset (rtems_disk_device *dd) |
---|
2253 | { |
---|
2254 | rtems_bdbuf_read_ahead_cancel (dd); |
---|
2255 | dd->read_ahead.trigger = RTEMS_DISK_READ_AHEAD_NO_TRIGGER; |
---|
2256 | } |
---|
2257 | |
---|
2258 | static void |
---|
2259 | rtems_bdbuf_check_read_ahead_trigger (rtems_disk_device *dd, |
---|
2260 | rtems_blkdev_bnum block) |
---|
2261 | { |
---|
2262 | if (bdbuf_cache.read_ahead_task != 0 |
---|
2263 | && dd->read_ahead.trigger == block |
---|
2264 | && !rtems_bdbuf_is_read_ahead_active (dd)) |
---|
2265 | { |
---|
2266 | rtems_status_code sc; |
---|
2267 | rtems_chain_control *chain = &bdbuf_cache.read_ahead_chain; |
---|
2268 | |
---|
2269 | if (rtems_chain_is_empty (chain)) |
---|
2270 | { |
---|
2271 | sc = rtems_event_send (bdbuf_cache.read_ahead_task, |
---|
2272 | RTEMS_BDBUF_READ_AHEAD_WAKE_UP); |
---|
2273 | if (sc != RTEMS_SUCCESSFUL) |
---|
2274 | rtems_bdbuf_fatal (RTEMS_BDBUF_FATAL_RA_WAKE_UP); |
---|
2275 | } |
---|
2276 | |
---|
2277 | rtems_chain_append_unprotected (chain, &dd->read_ahead.node); |
---|
2278 | } |
---|
2279 | } |
---|
2280 | |
---|
2281 | static void |
---|
2282 | rtems_bdbuf_set_read_ahead_trigger (rtems_disk_device *dd, |
---|
2283 | rtems_blkdev_bnum block) |
---|
2284 | { |
---|
2285 | if (dd->read_ahead.trigger != block) |
---|
2286 | { |
---|
2287 | rtems_bdbuf_read_ahead_cancel (dd); |
---|
2288 | dd->read_ahead.trigger = block + 1; |
---|
2289 | dd->read_ahead.next = block + 2; |
---|
2290 | } |
---|
2291 | } |
---|
2292 | |
---|
2293 | rtems_status_code |
---|
2294 | rtems_bdbuf_read (rtems_disk_device *dd, |
---|
2295 | rtems_blkdev_bnum block, |
---|
2296 | rtems_bdbuf_buffer **bd_ptr) |
---|
2297 | { |
---|
2298 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
2299 | rtems_bdbuf_buffer *bd = NULL; |
---|
2300 | rtems_blkdev_bnum media_block; |
---|
2301 | |
---|
2302 | rtems_bdbuf_lock_cache (); |
---|
2303 | |
---|
2304 | sc = rtems_bdbuf_get_media_block (dd, block, &media_block); |
---|
2305 | if (sc == RTEMS_SUCCESSFUL) |
---|
2306 | { |
---|
2307 | if (rtems_bdbuf_tracer) |
---|
2308 | printf ("bdbuf:read: %" PRIu32 " (%" PRIu32 ") (dev = %08x)\n", |
---|
2309 | media_block, block, (unsigned) dd->dev); |
---|
2310 | |
---|
2311 | bd = rtems_bdbuf_get_buffer_for_access (dd, media_block); |
---|
2312 | switch (bd->state) |
---|
2313 | { |
---|
2314 | case RTEMS_BDBUF_STATE_CACHED: |
---|
2315 | ++dd->stats.read_hits; |
---|
2316 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_ACCESS_CACHED); |
---|
2317 | break; |
---|
2318 | case RTEMS_BDBUF_STATE_MODIFIED: |
---|
2319 | ++dd->stats.read_hits; |
---|
2320 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_ACCESS_MODIFIED); |
---|
2321 | break; |
---|
2322 | case RTEMS_BDBUF_STATE_EMPTY: |
---|
2323 | ++dd->stats.read_misses; |
---|
2324 | rtems_bdbuf_set_read_ahead_trigger (dd, block); |
---|
2325 | sc = rtems_bdbuf_execute_read_request (dd, bd, 1); |
---|
2326 | if (sc == RTEMS_SUCCESSFUL) |
---|
2327 | { |
---|
2328 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_ACCESS_CACHED); |
---|
2329 | rtems_chain_extract_unprotected (&bd->link); |
---|
2330 | rtems_bdbuf_group_obtain (bd); |
---|
2331 | } |
---|
2332 | else |
---|
2333 | { |
---|
2334 | bd = NULL; |
---|
2335 | } |
---|
2336 | break; |
---|
2337 | default: |
---|
2338 | rtems_bdbuf_fatal_with_state (bd->state, RTEMS_BDBUF_FATAL_STATE_4); |
---|
2339 | break; |
---|
2340 | } |
---|
2341 | |
---|
2342 | rtems_bdbuf_check_read_ahead_trigger (dd, block); |
---|
2343 | } |
---|
2344 | |
---|
2345 | rtems_bdbuf_unlock_cache (); |
---|
2346 | |
---|
2347 | *bd_ptr = bd; |
---|
2348 | |
---|
2349 | return sc; |
---|
2350 | } |
---|
2351 | |
---|
2352 | static rtems_status_code |
---|
2353 | rtems_bdbuf_check_bd_and_lock_cache (rtems_bdbuf_buffer *bd, const char *kind) |
---|
2354 | { |
---|
2355 | if (bd == NULL) |
---|
2356 | return RTEMS_INVALID_ADDRESS; |
---|
2357 | if (rtems_bdbuf_tracer) |
---|
2358 | { |
---|
2359 | printf ("bdbuf:%s: %" PRIu32 "\n", kind, bd->block); |
---|
2360 | rtems_bdbuf_show_users (kind, bd); |
---|
2361 | } |
---|
2362 | rtems_bdbuf_lock_cache(); |
---|
2363 | |
---|
2364 | return RTEMS_SUCCESSFUL; |
---|
2365 | } |
---|
2366 | |
---|
2367 | rtems_status_code |
---|
2368 | rtems_bdbuf_release (rtems_bdbuf_buffer *bd) |
---|
2369 | { |
---|
2370 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
2371 | |
---|
2372 | sc = rtems_bdbuf_check_bd_and_lock_cache (bd, "release"); |
---|
2373 | if (sc != RTEMS_SUCCESSFUL) |
---|
2374 | return sc; |
---|
2375 | |
---|
2376 | switch (bd->state) |
---|
2377 | { |
---|
2378 | case RTEMS_BDBUF_STATE_ACCESS_CACHED: |
---|
2379 | rtems_bdbuf_add_to_lru_list_after_access (bd); |
---|
2380 | break; |
---|
2381 | case RTEMS_BDBUF_STATE_ACCESS_EMPTY: |
---|
2382 | case RTEMS_BDBUF_STATE_ACCESS_PURGED: |
---|
2383 | rtems_bdbuf_discard_buffer_after_access (bd); |
---|
2384 | break; |
---|
2385 | case RTEMS_BDBUF_STATE_ACCESS_MODIFIED: |
---|
2386 | rtems_bdbuf_add_to_modified_list_after_access (bd); |
---|
2387 | break; |
---|
2388 | default: |
---|
2389 | rtems_bdbuf_fatal_with_state (bd->state, RTEMS_BDBUF_FATAL_STATE_0); |
---|
2390 | break; |
---|
2391 | } |
---|
2392 | |
---|
2393 | if (rtems_bdbuf_tracer) |
---|
2394 | rtems_bdbuf_show_usage (); |
---|
2395 | |
---|
2396 | rtems_bdbuf_unlock_cache (); |
---|
2397 | |
---|
2398 | return RTEMS_SUCCESSFUL; |
---|
2399 | } |
---|
2400 | |
---|
2401 | rtems_status_code |
---|
2402 | rtems_bdbuf_release_modified (rtems_bdbuf_buffer *bd) |
---|
2403 | { |
---|
2404 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
2405 | |
---|
2406 | sc = rtems_bdbuf_check_bd_and_lock_cache (bd, "release modified"); |
---|
2407 | if (sc != RTEMS_SUCCESSFUL) |
---|
2408 | return sc; |
---|
2409 | |
---|
2410 | switch (bd->state) |
---|
2411 | { |
---|
2412 | case RTEMS_BDBUF_STATE_ACCESS_CACHED: |
---|
2413 | case RTEMS_BDBUF_STATE_ACCESS_EMPTY: |
---|
2414 | case RTEMS_BDBUF_STATE_ACCESS_MODIFIED: |
---|
2415 | rtems_bdbuf_add_to_modified_list_after_access (bd); |
---|
2416 | break; |
---|
2417 | case RTEMS_BDBUF_STATE_ACCESS_PURGED: |
---|
2418 | rtems_bdbuf_discard_buffer_after_access (bd); |
---|
2419 | break; |
---|
2420 | default: |
---|
2421 | rtems_bdbuf_fatal_with_state (bd->state, RTEMS_BDBUF_FATAL_STATE_6); |
---|
2422 | break; |
---|
2423 | } |
---|
2424 | |
---|
2425 | if (rtems_bdbuf_tracer) |
---|
2426 | rtems_bdbuf_show_usage (); |
---|
2427 | |
---|
2428 | rtems_bdbuf_unlock_cache (); |
---|
2429 | |
---|
2430 | return RTEMS_SUCCESSFUL; |
---|
2431 | } |
---|
2432 | |
---|
2433 | rtems_status_code |
---|
2434 | rtems_bdbuf_sync (rtems_bdbuf_buffer *bd) |
---|
2435 | { |
---|
2436 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
2437 | |
---|
2438 | sc = rtems_bdbuf_check_bd_and_lock_cache (bd, "sync"); |
---|
2439 | if (sc != RTEMS_SUCCESSFUL) |
---|
2440 | return sc; |
---|
2441 | |
---|
2442 | switch (bd->state) |
---|
2443 | { |
---|
2444 | case RTEMS_BDBUF_STATE_ACCESS_CACHED: |
---|
2445 | case RTEMS_BDBUF_STATE_ACCESS_EMPTY: |
---|
2446 | case RTEMS_BDBUF_STATE_ACCESS_MODIFIED: |
---|
2447 | rtems_bdbuf_sync_after_access (bd); |
---|
2448 | break; |
---|
2449 | case RTEMS_BDBUF_STATE_ACCESS_PURGED: |
---|
2450 | rtems_bdbuf_discard_buffer_after_access (bd); |
---|
2451 | break; |
---|
2452 | default: |
---|
2453 | rtems_bdbuf_fatal_with_state (bd->state, RTEMS_BDBUF_FATAL_STATE_5); |
---|
2454 | break; |
---|
2455 | } |
---|
2456 | |
---|
2457 | if (rtems_bdbuf_tracer) |
---|
2458 | rtems_bdbuf_show_usage (); |
---|
2459 | |
---|
2460 | rtems_bdbuf_unlock_cache (); |
---|
2461 | |
---|
2462 | return RTEMS_SUCCESSFUL; |
---|
2463 | } |
---|
2464 | |
---|
2465 | rtems_status_code |
---|
2466 | rtems_bdbuf_syncdev (rtems_disk_device *dd) |
---|
2467 | { |
---|
2468 | if (rtems_bdbuf_tracer) |
---|
2469 | printf ("bdbuf:syncdev: %08x\n", (unsigned) dd->dev); |
---|
2470 | |
---|
2471 | /* |
---|
2472 | * Take the sync lock before locking the cache. Once we have the sync lock we |
---|
2473 | * can lock the cache. If another thread has the sync lock it will cause this |
---|
2474 | * thread to block until it owns the sync lock then it can own the cache. The |
---|
2475 | * sync lock can only be obtained with the cache unlocked. |
---|
2476 | */ |
---|
2477 | rtems_bdbuf_lock_sync (); |
---|
2478 | rtems_bdbuf_lock_cache (); |
---|
2479 | |
---|
2480 | /* |
---|
2481 | * Set the cache to have a sync active for a specific device and let the swap |
---|
2482 | * out task know the id of the requester to wake when done. |
---|
2483 | * |
---|
2484 | * The swap out task will negate the sync active flag when no more buffers |
---|
2485 | * for the device are held on the "modified for sync" queues. |
---|
2486 | */ |
---|
2487 | bdbuf_cache.sync_active = true; |
---|
2488 | bdbuf_cache.sync_requester = rtems_task_self (); |
---|
2489 | bdbuf_cache.sync_device = dd; |
---|
2490 | |
---|
2491 | rtems_bdbuf_wake_swapper (); |
---|
2492 | rtems_bdbuf_unlock_cache (); |
---|
2493 | rtems_bdbuf_wait_for_transient_event (); |
---|
2494 | rtems_bdbuf_unlock_sync (); |
---|
2495 | |
---|
2496 | return RTEMS_SUCCESSFUL; |
---|
2497 | } |
---|
2498 | |
---|
2499 | /** |
---|
2500 | * Swapout transfer to the driver. The driver will break this I/O into groups |
---|
2501 | * of consecutive write requests is multiple consecutive buffers are required |
---|
2502 | * by the driver. The cache is not locked. |
---|
2503 | * |
---|
2504 | * @param transfer The transfer transaction. |
---|
2505 | */ |
---|
2506 | static void |
---|
2507 | rtems_bdbuf_swapout_write (rtems_bdbuf_swapout_transfer* transfer) |
---|
2508 | { |
---|
2509 | rtems_chain_node *node; |
---|
2510 | |
---|
2511 | if (rtems_bdbuf_tracer) |
---|
2512 | printf ("bdbuf:swapout transfer: %08x\n", (unsigned) transfer->dd->dev); |
---|
2513 | |
---|
2514 | /* |
---|
2515 | * If there are buffers to transfer to the media transfer them. |
---|
2516 | */ |
---|
2517 | if (!rtems_chain_is_empty (&transfer->bds)) |
---|
2518 | { |
---|
2519 | /* |
---|
2520 | * The last block number used when the driver only supports |
---|
2521 | * continuous blocks in a single request. |
---|
2522 | */ |
---|
2523 | uint32_t last_block = 0; |
---|
2524 | |
---|
2525 | rtems_disk_device *dd = transfer->dd; |
---|
2526 | uint32_t media_blocks_per_block = dd->media_blocks_per_block; |
---|
2527 | bool need_continuous_blocks = |
---|
2528 | (dd->phys_dev->capabilities & RTEMS_BLKDEV_CAP_MULTISECTOR_CONT) != 0; |
---|
2529 | |
---|
2530 | /* |
---|
2531 | * Take as many buffers as configured and pass to the driver. Note, the |
---|
2532 | * API to the drivers has an array of buffers and if a chain was passed |
---|
2533 | * we could have just passed the list. If the driver API is updated it |
---|
2534 | * should be possible to make this change with little effect in this |
---|
2535 | * code. The array that is passed is broken in design and should be |
---|
2536 | * removed. Merging members of a struct into the first member is |
---|
2537 | * trouble waiting to happen. |
---|
2538 | */ |
---|
2539 | transfer->write_req.status = RTEMS_RESOURCE_IN_USE; |
---|
2540 | transfer->write_req.bufnum = 0; |
---|
2541 | |
---|
2542 | while ((node = rtems_chain_get_unprotected(&transfer->bds)) != NULL) |
---|
2543 | { |
---|
2544 | rtems_bdbuf_buffer* bd = (rtems_bdbuf_buffer*) node; |
---|
2545 | bool write = false; |
---|
2546 | |
---|
2547 | /* |
---|
2548 | * If the device only accepts sequential buffers and this is not the |
---|
2549 | * first buffer (the first is always sequential, and the buffer is not |
---|
2550 | * sequential then put the buffer back on the transfer chain and write |
---|
2551 | * the committed buffers. |
---|
2552 | */ |
---|
2553 | |
---|
2554 | if (rtems_bdbuf_tracer) |
---|
2555 | printf ("bdbuf:swapout write: bd:%" PRIu32 ", bufnum:%" PRIu32 " mode:%s\n", |
---|
2556 | bd->block, transfer->write_req.bufnum, |
---|
2557 | need_continuous_blocks ? "MULTI" : "SCAT"); |
---|
2558 | |
---|
2559 | if (need_continuous_blocks && transfer->write_req.bufnum && |
---|
2560 | bd->block != last_block + media_blocks_per_block) |
---|
2561 | { |
---|
2562 | rtems_chain_prepend_unprotected (&transfer->bds, &bd->link); |
---|
2563 | write = true; |
---|
2564 | } |
---|
2565 | else |
---|
2566 | { |
---|
2567 | rtems_blkdev_sg_buffer* buf; |
---|
2568 | buf = &transfer->write_req.bufs[transfer->write_req.bufnum]; |
---|
2569 | transfer->write_req.bufnum++; |
---|
2570 | buf->user = bd; |
---|
2571 | buf->block = bd->block; |
---|
2572 | buf->length = dd->block_size; |
---|
2573 | buf->buffer = bd->buffer; |
---|
2574 | last_block = bd->block; |
---|
2575 | } |
---|
2576 | |
---|
2577 | /* |
---|
2578 | * Perform the transfer if there are no more buffers, or the transfer |
---|
2579 | * size has reached the configured max. value. |
---|
2580 | */ |
---|
2581 | |
---|
2582 | if (rtems_chain_is_empty (&transfer->bds) || |
---|
2583 | (transfer->write_req.bufnum >= bdbuf_config.max_write_blocks)) |
---|
2584 | write = true; |
---|
2585 | |
---|
2586 | if (write) |
---|
2587 | { |
---|
2588 | rtems_bdbuf_execute_transfer_request (dd, &transfer->write_req, false); |
---|
2589 | |
---|
2590 | transfer->write_req.status = RTEMS_RESOURCE_IN_USE; |
---|
2591 | transfer->write_req.bufnum = 0; |
---|
2592 | } |
---|
2593 | } |
---|
2594 | |
---|
2595 | /* |
---|
2596 | * If sync'ing and the deivce is capability of handling a sync IO control |
---|
2597 | * call perform the call. |
---|
2598 | */ |
---|
2599 | if (transfer->syncing && |
---|
2600 | (dd->phys_dev->capabilities & RTEMS_BLKDEV_CAP_SYNC)) |
---|
2601 | { |
---|
2602 | /* int result = */ dd->ioctl (dd->phys_dev, RTEMS_BLKDEV_REQ_SYNC, NULL); |
---|
2603 | /* How should the error be handled ? */ |
---|
2604 | } |
---|
2605 | } |
---|
2606 | } |
---|
2607 | |
---|
2608 | /** |
---|
2609 | * Process the modified list of buffers. There is a sync or modified list that |
---|
2610 | * needs to be handled so we have a common function to do the work. |
---|
2611 | * |
---|
2612 | * @param dd_ptr Pointer to the device to handle. If BDBUF_INVALID_DEV no |
---|
2613 | * device is selected so select the device of the first buffer to be written to |
---|
2614 | * disk. |
---|
2615 | * @param chain The modified chain to process. |
---|
2616 | * @param transfer The chain to append buffers to be written too. |
---|
2617 | * @param sync_active If true this is a sync operation so expire all timers. |
---|
2618 | * @param update_timers If true update the timers. |
---|
2619 | * @param timer_delta It update_timers is true update the timers by this |
---|
2620 | * amount. |
---|
2621 | */ |
---|
2622 | static void |
---|
2623 | rtems_bdbuf_swapout_modified_processing (rtems_disk_device **dd_ptr, |
---|
2624 | rtems_chain_control* chain, |
---|
2625 | rtems_chain_control* transfer, |
---|
2626 | bool sync_active, |
---|
2627 | bool update_timers, |
---|
2628 | uint32_t timer_delta) |
---|
2629 | { |
---|
2630 | if (!rtems_chain_is_empty (chain)) |
---|
2631 | { |
---|
2632 | rtems_chain_node* node = rtems_chain_head (chain); |
---|
2633 | bool sync_all; |
---|
2634 | |
---|
2635 | node = node->next; |
---|
2636 | |
---|
2637 | /* |
---|
2638 | * A sync active with no valid dev means sync all. |
---|
2639 | */ |
---|
2640 | if (sync_active && (*dd_ptr == BDBUF_INVALID_DEV)) |
---|
2641 | sync_all = true; |
---|
2642 | else |
---|
2643 | sync_all = false; |
---|
2644 | |
---|
2645 | while (!rtems_chain_is_tail (chain, node)) |
---|
2646 | { |
---|
2647 | rtems_bdbuf_buffer* bd = (rtems_bdbuf_buffer*) node; |
---|
2648 | |
---|
2649 | /* |
---|
2650 | * Check if the buffer's hold timer has reached 0. If a sync is active |
---|
2651 | * or someone waits for a buffer written force all the timers to 0. |
---|
2652 | * |
---|
2653 | * @note Lots of sync requests will skew this timer. It should be based |
---|
2654 | * on TOD to be accurate. Does it matter ? |
---|
2655 | */ |
---|
2656 | if (sync_all || (sync_active && (*dd_ptr == bd->dd)) |
---|
2657 | || rtems_bdbuf_has_buffer_waiters ()) |
---|
2658 | bd->hold_timer = 0; |
---|
2659 | |
---|
2660 | if (bd->hold_timer) |
---|
2661 | { |
---|
2662 | if (update_timers) |
---|
2663 | { |
---|
2664 | if (bd->hold_timer > timer_delta) |
---|
2665 | bd->hold_timer -= timer_delta; |
---|
2666 | else |
---|
2667 | bd->hold_timer = 0; |
---|
2668 | } |
---|
2669 | |
---|
2670 | if (bd->hold_timer) |
---|
2671 | { |
---|
2672 | node = node->next; |
---|
2673 | continue; |
---|
2674 | } |
---|
2675 | } |
---|
2676 | |
---|
2677 | /* |
---|
2678 | * This assumes we can set it to BDBUF_INVALID_DEV which is just an |
---|
2679 | * assumption. Cannot use the transfer list being empty the sync dev |
---|
2680 | * calls sets the dev to use. |
---|
2681 | */ |
---|
2682 | if (*dd_ptr == BDBUF_INVALID_DEV) |
---|
2683 | *dd_ptr = bd->dd; |
---|
2684 | |
---|
2685 | if (bd->dd == *dd_ptr) |
---|
2686 | { |
---|
2687 | rtems_chain_node* next_node = node->next; |
---|
2688 | rtems_chain_node* tnode = rtems_chain_tail (transfer); |
---|
2689 | |
---|
2690 | /* |
---|
2691 | * The blocks on the transfer list are sorted in block order. This |
---|
2692 | * means multi-block transfers for drivers that require consecutive |
---|
2693 | * blocks perform better with sorted blocks and for real disks it may |
---|
2694 | * help lower head movement. |
---|
2695 | */ |
---|
2696 | |
---|
2697 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_TRANSFER); |
---|
2698 | |
---|
2699 | rtems_chain_extract_unprotected (node); |
---|
2700 | |
---|
2701 | tnode = tnode->previous; |
---|
2702 | |
---|
2703 | while (node && !rtems_chain_is_head (transfer, tnode)) |
---|
2704 | { |
---|
2705 | rtems_bdbuf_buffer* tbd = (rtems_bdbuf_buffer*) tnode; |
---|
2706 | |
---|
2707 | if (bd->block > tbd->block) |
---|
2708 | { |
---|
2709 | rtems_chain_insert_unprotected (tnode, node); |
---|
2710 | node = NULL; |
---|
2711 | } |
---|
2712 | else |
---|
2713 | tnode = tnode->previous; |
---|
2714 | } |
---|
2715 | |
---|
2716 | if (node) |
---|
2717 | rtems_chain_prepend_unprotected (transfer, node); |
---|
2718 | |
---|
2719 | node = next_node; |
---|
2720 | } |
---|
2721 | else |
---|
2722 | { |
---|
2723 | node = node->next; |
---|
2724 | } |
---|
2725 | } |
---|
2726 | } |
---|
2727 | } |
---|
2728 | |
---|
2729 | /** |
---|
2730 | * Process the cache's modified buffers. Check the sync list first then the |
---|
2731 | * modified list extracting the buffers suitable to be written to disk. We have |
---|
2732 | * a device at a time. The task level loop will repeat this operation while |
---|
2733 | * there are buffers to be written. If the transfer fails place the buffers |
---|
2734 | * back on the modified list and try again later. The cache is unlocked while |
---|
2735 | * the buffers are being written to disk. |
---|
2736 | * |
---|
2737 | * @param timer_delta It update_timers is true update the timers by this |
---|
2738 | * amount. |
---|
2739 | * @param update_timers If true update the timers. |
---|
2740 | * @param transfer The transfer transaction data. |
---|
2741 | * |
---|
2742 | * @retval true Buffers where written to disk so scan again. |
---|
2743 | * @retval false No buffers where written to disk. |
---|
2744 | */ |
---|
2745 | static bool |
---|
2746 | rtems_bdbuf_swapout_processing (unsigned long timer_delta, |
---|
2747 | bool update_timers, |
---|
2748 | rtems_bdbuf_swapout_transfer* transfer) |
---|
2749 | { |
---|
2750 | rtems_bdbuf_swapout_worker* worker; |
---|
2751 | bool transfered_buffers = false; |
---|
2752 | bool sync_active; |
---|
2753 | |
---|
2754 | rtems_bdbuf_lock_cache (); |
---|
2755 | |
---|
2756 | /* |
---|
2757 | * To set this to true you need the cache and the sync lock. |
---|
2758 | */ |
---|
2759 | sync_active = bdbuf_cache.sync_active; |
---|
2760 | |
---|
2761 | /* |
---|
2762 | * If a sync is active do not use a worker because the current code does not |
---|
2763 | * cleaning up after. We need to know the buffers have been written when |
---|
2764 | * syncing to release sync lock and currently worker threads do not return to |
---|
2765 | * here. We do not know the worker is the last in a sequence of sync writes |
---|
2766 | * until after we have it running so we do not know to tell it to release the |
---|
2767 | * lock. The simplest solution is to get the main swap out task perform all |
---|
2768 | * sync operations. |
---|
2769 | */ |
---|
2770 | if (sync_active) |
---|
2771 | worker = NULL; |
---|
2772 | else |
---|
2773 | { |
---|
2774 | worker = (rtems_bdbuf_swapout_worker*) |
---|
2775 | rtems_chain_get_unprotected (&bdbuf_cache.swapout_free_workers); |
---|
2776 | if (worker) |
---|
2777 | transfer = &worker->transfer; |
---|
2778 | } |
---|
2779 | |
---|
2780 | rtems_chain_initialize_empty (&transfer->bds); |
---|
2781 | transfer->dd = BDBUF_INVALID_DEV; |
---|
2782 | transfer->syncing = sync_active; |
---|
2783 | |
---|
2784 | /* |
---|
2785 | * When the sync is for a device limit the sync to that device. If the sync |
---|
2786 | * is for a buffer handle process the devices in the order on the sync |
---|
2787 | * list. This means the dev is BDBUF_INVALID_DEV. |
---|
2788 | */ |
---|
2789 | if (sync_active) |
---|
2790 | transfer->dd = bdbuf_cache.sync_device; |
---|
2791 | |
---|
2792 | /* |
---|
2793 | * If we have any buffers in the sync queue move them to the modified |
---|
2794 | * list. The first sync buffer will select the device we use. |
---|
2795 | */ |
---|
2796 | rtems_bdbuf_swapout_modified_processing (&transfer->dd, |
---|
2797 | &bdbuf_cache.sync, |
---|
2798 | &transfer->bds, |
---|
2799 | true, false, |
---|
2800 | timer_delta); |
---|
2801 | |
---|
2802 | /* |
---|
2803 | * Process the cache's modified list. |
---|
2804 | */ |
---|
2805 | rtems_bdbuf_swapout_modified_processing (&transfer->dd, |
---|
2806 | &bdbuf_cache.modified, |
---|
2807 | &transfer->bds, |
---|
2808 | sync_active, |
---|
2809 | update_timers, |
---|
2810 | timer_delta); |
---|
2811 | |
---|
2812 | /* |
---|
2813 | * We have all the buffers that have been modified for this device so the |
---|
2814 | * cache can be unlocked because the state of each buffer has been set to |
---|
2815 | * TRANSFER. |
---|
2816 | */ |
---|
2817 | rtems_bdbuf_unlock_cache (); |
---|
2818 | |
---|
2819 | /* |
---|
2820 | * If there are buffers to transfer to the media transfer them. |
---|
2821 | */ |
---|
2822 | if (!rtems_chain_is_empty (&transfer->bds)) |
---|
2823 | { |
---|
2824 | if (worker) |
---|
2825 | { |
---|
2826 | rtems_status_code sc = rtems_event_send (worker->id, |
---|
2827 | RTEMS_BDBUF_SWAPOUT_SYNC); |
---|
2828 | if (sc != RTEMS_SUCCESSFUL) |
---|
2829 | rtems_bdbuf_fatal (RTEMS_BDBUF_FATAL_SO_WAKE_2); |
---|
2830 | } |
---|
2831 | else |
---|
2832 | { |
---|
2833 | rtems_bdbuf_swapout_write (transfer); |
---|
2834 | } |
---|
2835 | |
---|
2836 | transfered_buffers = true; |
---|
2837 | } |
---|
2838 | |
---|
2839 | if (sync_active && !transfered_buffers) |
---|
2840 | { |
---|
2841 | rtems_id sync_requester; |
---|
2842 | rtems_bdbuf_lock_cache (); |
---|
2843 | sync_requester = bdbuf_cache.sync_requester; |
---|
2844 | bdbuf_cache.sync_active = false; |
---|
2845 | bdbuf_cache.sync_requester = 0; |
---|
2846 | rtems_bdbuf_unlock_cache (); |
---|
2847 | if (sync_requester) |
---|
2848 | rtems_event_transient_send (sync_requester); |
---|
2849 | } |
---|
2850 | |
---|
2851 | return transfered_buffers; |
---|
2852 | } |
---|
2853 | |
---|
2854 | /** |
---|
2855 | * The swapout worker thread body. |
---|
2856 | * |
---|
2857 | * @param arg A pointer to the worker thread's private data. |
---|
2858 | * @return rtems_task Not used. |
---|
2859 | */ |
---|
2860 | static rtems_task |
---|
2861 | rtems_bdbuf_swapout_worker_task (rtems_task_argument arg) |
---|
2862 | { |
---|
2863 | rtems_bdbuf_swapout_worker* worker = (rtems_bdbuf_swapout_worker*) arg; |
---|
2864 | |
---|
2865 | while (worker->enabled) |
---|
2866 | { |
---|
2867 | rtems_bdbuf_wait_for_event (RTEMS_BDBUF_SWAPOUT_SYNC); |
---|
2868 | |
---|
2869 | rtems_bdbuf_swapout_write (&worker->transfer); |
---|
2870 | |
---|
2871 | rtems_bdbuf_lock_cache (); |
---|
2872 | |
---|
2873 | rtems_chain_initialize_empty (&worker->transfer.bds); |
---|
2874 | worker->transfer.dd = BDBUF_INVALID_DEV; |
---|
2875 | |
---|
2876 | rtems_chain_append_unprotected (&bdbuf_cache.swapout_free_workers, &worker->link); |
---|
2877 | |
---|
2878 | rtems_bdbuf_unlock_cache (); |
---|
2879 | } |
---|
2880 | |
---|
2881 | free (worker); |
---|
2882 | |
---|
2883 | rtems_task_delete (RTEMS_SELF); |
---|
2884 | } |
---|
2885 | |
---|
2886 | /** |
---|
2887 | * Close the swapout worker threads. |
---|
2888 | */ |
---|
2889 | static void |
---|
2890 | rtems_bdbuf_swapout_workers_close (void) |
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2891 | { |
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2892 | rtems_chain_node* node; |
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2893 | |
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2894 | rtems_bdbuf_lock_cache (); |
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2895 | |
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2896 | node = rtems_chain_first (&bdbuf_cache.swapout_free_workers); |
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2897 | while (!rtems_chain_is_tail (&bdbuf_cache.swapout_free_workers, node)) |
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2898 | { |
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2899 | rtems_bdbuf_swapout_worker* worker = (rtems_bdbuf_swapout_worker*) node; |
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2900 | worker->enabled = false; |
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2901 | rtems_event_send (worker->id, RTEMS_BDBUF_SWAPOUT_SYNC); |
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2902 | node = rtems_chain_next (node); |
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2903 | } |
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2904 | |
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2905 | rtems_bdbuf_unlock_cache (); |
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2906 | } |
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2907 | |
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2908 | /** |
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2909 | * Body of task which takes care on flushing modified buffers to the disk. |
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2910 | * |
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2911 | * @param arg A pointer to the global cache data. Use the global variable and |
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2912 | * not this. |
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2913 | * @return rtems_task Not used. |
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2914 | */ |
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2915 | static rtems_task |
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2916 | rtems_bdbuf_swapout_task (rtems_task_argument arg) |
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2917 | { |
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2918 | rtems_bdbuf_swapout_transfer* transfer = (rtems_bdbuf_swapout_transfer *) arg; |
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2919 | uint32_t period_in_ticks; |
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2920 | const uint32_t period_in_msecs = bdbuf_config.swapout_period; |
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2921 | uint32_t timer_delta; |
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2922 | |
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2923 | /* |
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2924 | * Localise the period. |
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2925 | */ |
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2926 | period_in_ticks = RTEMS_MICROSECONDS_TO_TICKS (period_in_msecs * 1000); |
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2927 | |
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2928 | /* |
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2929 | * This is temporary. Needs to be changed to use the real time clock. |
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2930 | */ |
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2931 | timer_delta = period_in_msecs; |
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2932 | |
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2933 | while (bdbuf_cache.swapout_enabled) |
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2934 | { |
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2935 | rtems_event_set out; |
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2936 | rtems_status_code sc; |
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2937 | |
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2938 | /* |
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2939 | * Only update the timers once in the processing cycle. |
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2940 | */ |
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2941 | bool update_timers = true; |
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2942 | |
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2943 | /* |
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2944 | * If we write buffers to any disk perform a check again. We only write a |
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2945 | * single device at a time and the cache may have more than one device's |
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2946 | * buffers modified waiting to be written. |
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2947 | */ |
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2948 | bool transfered_buffers; |
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2949 | |
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2950 | do |
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2951 | { |
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2952 | transfered_buffers = false; |
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2953 | |
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2954 | /* |
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2955 | * Extact all the buffers we find for a specific device. The device is |
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2956 | * the first one we find on a modified list. Process the sync queue of |
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2957 | * buffers first. |
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2958 | */ |
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2959 | if (rtems_bdbuf_swapout_processing (timer_delta, |
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2960 | update_timers, |
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2961 | transfer)) |
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2962 | { |
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2963 | transfered_buffers = true; |
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2964 | } |
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2965 | |
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2966 | /* |
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2967 | * Only update the timers once. |
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2968 | */ |
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2969 | update_timers = false; |
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2970 | } |
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2971 | while (transfered_buffers); |
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2972 | |
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2973 | sc = rtems_event_receive (RTEMS_BDBUF_SWAPOUT_SYNC, |
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2974 | RTEMS_EVENT_ALL | RTEMS_WAIT, |
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2975 | period_in_ticks, |
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2976 | &out); |
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2977 | |
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2978 | if ((sc != RTEMS_SUCCESSFUL) && (sc != RTEMS_TIMEOUT)) |
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2979 | rtems_bdbuf_fatal (RTEMS_BDBUF_FATAL_SWAPOUT_RE); |
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2980 | } |
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2981 | |
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2982 | rtems_bdbuf_swapout_workers_close (); |
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2983 | |
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2984 | free (transfer); |
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2985 | |
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2986 | rtems_task_delete (RTEMS_SELF); |
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2987 | } |
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2988 | |
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2989 | static void |
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2990 | rtems_bdbuf_purge_list (rtems_chain_control *purge_list) |
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2991 | { |
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2992 | bool wake_buffer_waiters = false; |
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2993 | rtems_chain_node *node = NULL; |
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2994 | |
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2995 | while ((node = rtems_chain_get_unprotected (purge_list)) != NULL) |
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2996 | { |
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2997 | rtems_bdbuf_buffer *bd = (rtems_bdbuf_buffer *) node; |
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2998 | |
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2999 | if (bd->waiters == 0) |
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3000 | wake_buffer_waiters = true; |
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3001 | |
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3002 | rtems_bdbuf_discard_buffer (bd); |
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3003 | } |
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3004 | |
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3005 | if (wake_buffer_waiters) |
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3006 | rtems_bdbuf_wake (&bdbuf_cache.buffer_waiters); |
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3007 | } |
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3008 | |
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3009 | static void |
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3010 | rtems_bdbuf_gather_for_purge (rtems_chain_control *purge_list, |
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3011 | const rtems_disk_device *dd) |
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3012 | { |
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3013 | rtems_bdbuf_buffer *stack [RTEMS_BDBUF_AVL_MAX_HEIGHT]; |
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3014 | rtems_bdbuf_buffer **prev = stack; |
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3015 | rtems_bdbuf_buffer *cur = bdbuf_cache.tree; |
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3016 | |
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3017 | *prev = NULL; |
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3018 | |
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3019 | while (cur != NULL) |
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3020 | { |
---|
3021 | if (cur->dd == dd) |
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3022 | { |
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3023 | switch (cur->state) |
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3024 | { |
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3025 | case RTEMS_BDBUF_STATE_FREE: |
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3026 | case RTEMS_BDBUF_STATE_EMPTY: |
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3027 | case RTEMS_BDBUF_STATE_ACCESS_PURGED: |
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3028 | case RTEMS_BDBUF_STATE_TRANSFER_PURGED: |
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3029 | break; |
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3030 | case RTEMS_BDBUF_STATE_SYNC: |
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3031 | rtems_bdbuf_wake (&bdbuf_cache.transfer_waiters); |
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3032 | /* Fall through */ |
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3033 | case RTEMS_BDBUF_STATE_MODIFIED: |
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3034 | rtems_bdbuf_group_release (cur); |
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3035 | /* Fall through */ |
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3036 | case RTEMS_BDBUF_STATE_CACHED: |
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3037 | rtems_chain_extract_unprotected (&cur->link); |
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3038 | rtems_chain_append_unprotected (purge_list, &cur->link); |
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3039 | break; |
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3040 | case RTEMS_BDBUF_STATE_TRANSFER: |
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3041 | rtems_bdbuf_set_state (cur, RTEMS_BDBUF_STATE_TRANSFER_PURGED); |
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3042 | break; |
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3043 | case RTEMS_BDBUF_STATE_ACCESS_CACHED: |
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3044 | case RTEMS_BDBUF_STATE_ACCESS_EMPTY: |
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3045 | case RTEMS_BDBUF_STATE_ACCESS_MODIFIED: |
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3046 | rtems_bdbuf_set_state (cur, RTEMS_BDBUF_STATE_ACCESS_PURGED); |
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3047 | break; |
---|
3048 | default: |
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3049 | rtems_bdbuf_fatal (RTEMS_BDBUF_FATAL_STATE_11); |
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3050 | } |
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3051 | } |
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3052 | |
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3053 | if (cur->avl.left != NULL) |
---|
3054 | { |
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3055 | /* Left */ |
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3056 | ++prev; |
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3057 | *prev = cur; |
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3058 | cur = cur->avl.left; |
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3059 | } |
---|
3060 | else if (cur->avl.right != NULL) |
---|
3061 | { |
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3062 | /* Right */ |
---|
3063 | ++prev; |
---|
3064 | *prev = cur; |
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3065 | cur = cur->avl.right; |
---|
3066 | } |
---|
3067 | else |
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3068 | { |
---|
3069 | while (*prev != NULL |
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3070 | && (cur == (*prev)->avl.right || (*prev)->avl.right == NULL)) |
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3071 | { |
---|
3072 | /* Up */ |
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3073 | cur = *prev; |
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3074 | --prev; |
---|
3075 | } |
---|
3076 | if (*prev != NULL) |
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3077 | /* Right */ |
---|
3078 | cur = (*prev)->avl.right; |
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3079 | else |
---|
3080 | /* Finished */ |
---|
3081 | cur = NULL; |
---|
3082 | } |
---|
3083 | } |
---|
3084 | } |
---|
3085 | |
---|
3086 | static void |
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3087 | rtems_bdbuf_do_purge_dev (rtems_disk_device *dd) |
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3088 | { |
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3089 | rtems_chain_control purge_list; |
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3090 | |
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3091 | rtems_chain_initialize_empty (&purge_list); |
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3092 | rtems_bdbuf_read_ahead_reset (dd); |
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3093 | rtems_bdbuf_gather_for_purge (&purge_list, dd); |
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3094 | rtems_bdbuf_purge_list (&purge_list); |
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3095 | } |
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3096 | |
---|
3097 | void |
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3098 | rtems_bdbuf_purge_dev (rtems_disk_device *dd) |
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3099 | { |
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3100 | rtems_bdbuf_lock_cache (); |
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3101 | rtems_bdbuf_do_purge_dev (dd); |
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3102 | rtems_bdbuf_unlock_cache (); |
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3103 | } |
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3104 | |
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3105 | rtems_status_code |
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3106 | rtems_bdbuf_set_block_size (rtems_disk_device *dd, |
---|
3107 | uint32_t block_size, |
---|
3108 | bool sync) |
---|
3109 | { |
---|
3110 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
3111 | |
---|
3112 | /* |
---|
3113 | * We do not care about the synchronization status since we will purge the |
---|
3114 | * device later. |
---|
3115 | */ |
---|
3116 | if (sync) |
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3117 | rtems_bdbuf_syncdev (dd); |
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3118 | |
---|
3119 | rtems_bdbuf_lock_cache (); |
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3120 | |
---|
3121 | if (block_size > 0) |
---|
3122 | { |
---|
3123 | size_t bds_per_group = rtems_bdbuf_bds_per_group (block_size); |
---|
3124 | |
---|
3125 | if (bds_per_group != 0) |
---|
3126 | { |
---|
3127 | int block_to_media_block_shift = 0; |
---|
3128 | uint32_t media_blocks_per_block = block_size / dd->media_block_size; |
---|
3129 | uint32_t one = 1; |
---|
3130 | |
---|
3131 | while ((one << block_to_media_block_shift) < media_blocks_per_block) |
---|
3132 | { |
---|
3133 | ++block_to_media_block_shift; |
---|
3134 | } |
---|
3135 | |
---|
3136 | if ((dd->media_block_size << block_to_media_block_shift) != block_size) |
---|
3137 | block_to_media_block_shift = -1; |
---|
3138 | |
---|
3139 | dd->block_size = block_size; |
---|
3140 | dd->block_count = dd->size / media_blocks_per_block; |
---|
3141 | dd->media_blocks_per_block = media_blocks_per_block; |
---|
3142 | dd->block_to_media_block_shift = block_to_media_block_shift; |
---|
3143 | dd->bds_per_group = bds_per_group; |
---|
3144 | |
---|
3145 | rtems_bdbuf_do_purge_dev (dd); |
---|
3146 | } |
---|
3147 | else |
---|
3148 | { |
---|
3149 | sc = RTEMS_INVALID_NUMBER; |
---|
3150 | } |
---|
3151 | } |
---|
3152 | else |
---|
3153 | { |
---|
3154 | sc = RTEMS_INVALID_NUMBER; |
---|
3155 | } |
---|
3156 | |
---|
3157 | rtems_bdbuf_unlock_cache (); |
---|
3158 | |
---|
3159 | return sc; |
---|
3160 | } |
---|
3161 | |
---|
3162 | static rtems_task |
---|
3163 | rtems_bdbuf_read_ahead_task (rtems_task_argument arg) |
---|
3164 | { |
---|
3165 | rtems_chain_control *chain = &bdbuf_cache.read_ahead_chain; |
---|
3166 | |
---|
3167 | while (bdbuf_cache.read_ahead_enabled) |
---|
3168 | { |
---|
3169 | rtems_chain_node *node; |
---|
3170 | |
---|
3171 | rtems_bdbuf_wait_for_event (RTEMS_BDBUF_READ_AHEAD_WAKE_UP); |
---|
3172 | rtems_bdbuf_lock_cache (); |
---|
3173 | |
---|
3174 | while ((node = rtems_chain_get_unprotected (chain)) != NULL) |
---|
3175 | { |
---|
3176 | rtems_disk_device *dd = |
---|
3177 | RTEMS_CONTAINER_OF (node, rtems_disk_device, read_ahead.node); |
---|
3178 | rtems_blkdev_bnum block = dd->read_ahead.next; |
---|
3179 | rtems_blkdev_bnum media_block = 0; |
---|
3180 | rtems_status_code sc = |
---|
3181 | rtems_bdbuf_get_media_block (dd, block, &media_block); |
---|
3182 | |
---|
3183 | rtems_chain_set_off_chain (&dd->read_ahead.node); |
---|
3184 | |
---|
3185 | if (sc == RTEMS_SUCCESSFUL) |
---|
3186 | { |
---|
3187 | rtems_bdbuf_buffer *bd = |
---|
3188 | rtems_bdbuf_get_buffer_for_read_ahead (dd, media_block); |
---|
3189 | |
---|
3190 | if (bd != NULL) |
---|
3191 | { |
---|
3192 | uint32_t transfer_count = dd->block_count - block; |
---|
3193 | uint32_t max_transfer_count = bdbuf_config.max_read_ahead_blocks; |
---|
3194 | |
---|
3195 | if (transfer_count >= max_transfer_count) |
---|
3196 | { |
---|
3197 | transfer_count = max_transfer_count; |
---|
3198 | dd->read_ahead.trigger = block + transfer_count / 2; |
---|
3199 | dd->read_ahead.next = block + transfer_count; |
---|
3200 | } |
---|
3201 | else |
---|
3202 | { |
---|
3203 | dd->read_ahead.trigger = RTEMS_DISK_READ_AHEAD_NO_TRIGGER; |
---|
3204 | } |
---|
3205 | |
---|
3206 | ++dd->stats.read_ahead_transfers; |
---|
3207 | rtems_bdbuf_execute_read_request (dd, bd, transfer_count); |
---|
3208 | } |
---|
3209 | } |
---|
3210 | else |
---|
3211 | { |
---|
3212 | dd->read_ahead.trigger = RTEMS_DISK_READ_AHEAD_NO_TRIGGER; |
---|
3213 | } |
---|
3214 | } |
---|
3215 | |
---|
3216 | rtems_bdbuf_unlock_cache (); |
---|
3217 | } |
---|
3218 | |
---|
3219 | rtems_task_delete (RTEMS_SELF); |
---|
3220 | } |
---|
3221 | |
---|
3222 | void rtems_bdbuf_get_device_stats (const rtems_disk_device *dd, |
---|
3223 | rtems_blkdev_stats *stats) |
---|
3224 | { |
---|
3225 | rtems_bdbuf_lock_cache (); |
---|
3226 | *stats = dd->stats; |
---|
3227 | rtems_bdbuf_unlock_cache (); |
---|
3228 | } |
---|
3229 | |
---|
3230 | void rtems_bdbuf_reset_device_stats (rtems_disk_device *dd) |
---|
3231 | { |
---|
3232 | rtems_bdbuf_lock_cache (); |
---|
3233 | memset (&dd->stats, 0, sizeof(dd->stats)); |
---|
3234 | rtems_bdbuf_unlock_cache (); |
---|
3235 | } |
---|