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) 2009-2012 embedded brains GmbH. |
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23 | * |
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24 | * @(#) bdbuf.c,v 1.14 2004/04/17 08:15:17 ralf Exp |
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25 | */ |
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26 | |
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27 | /** |
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28 | * Set to 1 to enable debug tracing. |
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29 | */ |
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30 | #define RTEMS_BDBUF_TRACE 0 |
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31 | |
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32 | #if HAVE_CONFIG_H |
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33 | #include "config.h" |
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34 | #endif |
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35 | #include <limits.h> |
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36 | #include <errno.h> |
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37 | #include <stdio.h> |
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38 | #include <string.h> |
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39 | #include <inttypes.h> |
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40 | |
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41 | #include <rtems.h> |
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42 | #include <rtems/error.h> |
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43 | #include <rtems/malloc.h> |
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44 | |
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45 | #include "rtems/bdbuf.h" |
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46 | |
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47 | #define BDBUF_INVALID_DEV NULL |
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48 | |
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49 | /* |
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50 | * Simpler label for this file. |
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51 | */ |
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52 | #define bdbuf_config rtems_bdbuf_configuration |
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53 | |
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54 | /** |
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55 | * A swapout transfer transaction data. This data is passed to a worked thread |
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56 | * to handle the write phase of the transfer. |
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57 | */ |
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58 | typedef struct rtems_bdbuf_swapout_transfer |
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59 | { |
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60 | rtems_chain_control bds; /**< The transfer list of BDs. */ |
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61 | const rtems_disk_device *dd; /**< The device the transfer is for. */ |
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62 | bool syncing; /**< The data is a sync'ing. */ |
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63 | rtems_blkdev_request* write_req; /**< The write request array. */ |
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64 | uint32_t bufs_per_bd; /**< Number of buffers per bd. */ |
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65 | } rtems_bdbuf_swapout_transfer; |
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66 | |
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67 | /** |
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68 | * Swapout worker thread. These are available to take processing from the |
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69 | * main swapout thread and handle the I/O operation. |
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70 | */ |
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71 | typedef struct rtems_bdbuf_swapout_worker |
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72 | { |
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73 | rtems_chain_node link; /**< The threads sit on a chain when |
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74 | * idle. */ |
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75 | rtems_id id; /**< The id of the task so we can wake |
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76 | * it. */ |
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77 | bool enabled; /**< The worker is enabled. */ |
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78 | rtems_bdbuf_swapout_transfer transfer; /**< The transfer data for this |
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79 | * thread. */ |
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80 | } rtems_bdbuf_swapout_worker; |
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81 | |
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82 | /** |
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83 | * Buffer waiters synchronization. |
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84 | */ |
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85 | typedef struct rtems_bdbuf_waiters { |
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86 | unsigned count; |
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87 | rtems_id sema; |
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88 | } rtems_bdbuf_waiters; |
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89 | |
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90 | /** |
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91 | * The BD buffer cache. |
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92 | */ |
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93 | typedef struct rtems_bdbuf_cache |
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94 | { |
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95 | rtems_id swapout; /**< Swapout task ID */ |
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96 | bool swapout_enabled; /**< Swapout is only running if |
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97 | * enabled. Set to false to kill the |
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98 | * swap out task. It deletes itself. */ |
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99 | rtems_chain_control swapout_workers; /**< The work threads for the swapout |
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100 | * task. */ |
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101 | |
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102 | rtems_bdbuf_buffer* bds; /**< Pointer to table of buffer |
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103 | * descriptors. */ |
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104 | void* buffers; /**< The buffer's memory. */ |
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105 | size_t buffer_min_count; /**< Number of minimum size buffers |
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106 | * that fit the buffer memory. */ |
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107 | size_t max_bds_per_group; /**< The number of BDs of minimum |
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108 | * buffer size that fit in a group. */ |
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109 | uint32_t flags; /**< Configuration flags. */ |
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110 | |
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111 | rtems_id lock; /**< The cache lock. It locks all |
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112 | * cache data, BD and lists. */ |
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113 | rtems_id sync_lock; /**< Sync calls block writes. */ |
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114 | bool sync_active; /**< True if a sync is active. */ |
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115 | rtems_id sync_requester; /**< The sync requester. */ |
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116 | const rtems_disk_device *sync_device; /**< The device to sync and |
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117 | * BDBUF_INVALID_DEV not a device |
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118 | * sync. */ |
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119 | |
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120 | rtems_bdbuf_buffer* tree; /**< Buffer descriptor lookup AVL tree |
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121 | * root. There is only one. */ |
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122 | rtems_chain_control lru; /**< Least recently used list */ |
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123 | rtems_chain_control modified; /**< Modified buffers list */ |
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124 | rtems_chain_control sync; /**< Buffers to sync list */ |
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125 | |
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126 | rtems_bdbuf_waiters access_waiters; /**< Wait for a buffer in |
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127 | * ACCESS_CACHED, ACCESS_MODIFIED or |
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128 | * ACCESS_EMPTY |
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129 | * state. */ |
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130 | rtems_bdbuf_waiters transfer_waiters; /**< Wait for a buffer in TRANSFER |
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131 | * state. */ |
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132 | rtems_bdbuf_waiters buffer_waiters; /**< Wait for a buffer and no one is |
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133 | * available. */ |
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134 | |
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135 | size_t group_count; /**< The number of groups. */ |
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136 | rtems_bdbuf_group* groups; /**< The groups. */ |
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137 | |
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138 | bool initialised; /**< Initialised state. */ |
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139 | } rtems_bdbuf_cache; |
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140 | |
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141 | /** |
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142 | * Fatal errors |
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143 | */ |
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144 | #define RTEMS_BLKDEV_FATAL_ERROR(n) \ |
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145 | (((uint32_t)'B' << 24) | ((uint32_t)(n) & (uint32_t)0x00FFFFFF)) |
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146 | |
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147 | #define RTEMS_BLKDEV_FATAL_BDBUF_STATE_11 RTEMS_BLKDEV_FATAL_ERROR(1) |
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148 | #define RTEMS_BLKDEV_FATAL_BDBUF_STATE_4 RTEMS_BLKDEV_FATAL_ERROR(2) |
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149 | #define RTEMS_BLKDEV_FATAL_BDBUF_STATE_5 RTEMS_BLKDEV_FATAL_ERROR(3) |
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150 | #define RTEMS_BLKDEV_FATAL_BDBUF_STATE_6 RTEMS_BLKDEV_FATAL_ERROR(4) |
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151 | #define RTEMS_BLKDEV_FATAL_BDBUF_STATE_7 RTEMS_BLKDEV_FATAL_ERROR(5) |
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152 | #define RTEMS_BLKDEV_FATAL_BDBUF_STATE_8 RTEMS_BLKDEV_FATAL_ERROR(6) |
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153 | #define RTEMS_BLKDEV_FATAL_BDBUF_STATE_9 RTEMS_BLKDEV_FATAL_ERROR(7) |
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154 | #define RTEMS_BLKDEV_FATAL_BDBUF_STATE_10 RTEMS_BLKDEV_FATAL_ERROR(8) |
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155 | #define RTEMS_BLKDEV_FATAL_BDBUF_TREE_RM RTEMS_BLKDEV_FATAL_ERROR(9) |
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156 | #define RTEMS_BLKDEV_FATAL_BDBUF_SWAPOUT RTEMS_BLKDEV_FATAL_ERROR(10) |
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157 | #define RTEMS_BLKDEV_FATAL_BDBUF_SYNC_LOCK RTEMS_BLKDEV_FATAL_ERROR(11) |
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158 | #define RTEMS_BLKDEV_FATAL_BDBUF_SYNC_UNLOCK RTEMS_BLKDEV_FATAL_ERROR(12) |
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159 | #define RTEMS_BLKDEV_FATAL_BDBUF_CACHE_LOCK RTEMS_BLKDEV_FATAL_ERROR(13) |
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160 | #define RTEMS_BLKDEV_FATAL_BDBUF_CACHE_UNLOCK RTEMS_BLKDEV_FATAL_ERROR(14) |
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161 | #define RTEMS_BLKDEV_FATAL_BDBUF_PREEMPT_DIS RTEMS_BLKDEV_FATAL_ERROR(15) |
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162 | #define RTEMS_BLKDEV_FATAL_BDBUF_CACHE_WAIT_2 RTEMS_BLKDEV_FATAL_ERROR(16) |
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163 | #define RTEMS_BLKDEV_FATAL_BDBUF_PREEMPT_RST RTEMS_BLKDEV_FATAL_ERROR(17) |
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164 | #define RTEMS_BLKDEV_FATAL_BDBUF_CACHE_WAIT_TO RTEMS_BLKDEV_FATAL_ERROR(18) |
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165 | #define RTEMS_BLKDEV_FATAL_BDBUF_CACHE_WAKE RTEMS_BLKDEV_FATAL_ERROR(19) |
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166 | #define RTEMS_BLKDEV_FATAL_BDBUF_SO_WAKE RTEMS_BLKDEV_FATAL_ERROR(20) |
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167 | #define RTEMS_BLKDEV_FATAL_BDBUF_SO_NOMEM RTEMS_BLKDEV_FATAL_ERROR(21) |
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168 | #define RTEMS_BLKDEV_FATAL_BDBUF_SO_WK_CREATE RTEMS_BLKDEV_FATAL_ERROR(22) |
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169 | #define RTEMS_BLKDEV_FATAL_BDBUF_SO_WK_START RTEMS_BLKDEV_FATAL_ERROR(23) |
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170 | #define BLKDEV_FATAL_BDBUF_SWAPOUT_RE RTEMS_BLKDEV_FATAL_ERROR(24) |
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171 | #define BLKDEV_FATAL_BDBUF_SWAPOUT_TS RTEMS_BLKDEV_FATAL_ERROR(25) |
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172 | #define RTEMS_BLKDEV_FATAL_BDBUF_WAIT_EVNT RTEMS_BLKDEV_FATAL_ERROR(26) |
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173 | #define RTEMS_BLKDEV_FATAL_BDBUF_RECYCLE RTEMS_BLKDEV_FATAL_ERROR(27) |
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174 | #define RTEMS_BLKDEV_FATAL_BDBUF_STATE_0 RTEMS_BLKDEV_FATAL_ERROR(28) |
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175 | #define RTEMS_BLKDEV_FATAL_BDBUF_STATE_1 RTEMS_BLKDEV_FATAL_ERROR(29) |
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176 | #define RTEMS_BLKDEV_FATAL_BDBUF_STATE_2 RTEMS_BLKDEV_FATAL_ERROR(30) |
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177 | |
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178 | /** |
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179 | * The events used in this code. These should be system events rather than |
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180 | * application events. |
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181 | */ |
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182 | #define RTEMS_BDBUF_TRANSFER_SYNC RTEMS_EVENT_1 |
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183 | #define RTEMS_BDBUF_SWAPOUT_SYNC RTEMS_EVENT_2 |
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184 | |
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185 | /** |
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186 | * The swap out task size. Should be more than enough for most drivers with |
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187 | * tracing turned on. |
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188 | */ |
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189 | #define SWAPOUT_TASK_STACK_SIZE (8 * 1024) |
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190 | |
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191 | /** |
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192 | * Lock semaphore attributes. This is used for locking type mutexes. |
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193 | * |
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194 | * @warning Priority inheritance is on. |
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195 | */ |
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196 | #define RTEMS_BDBUF_CACHE_LOCK_ATTRIBS \ |
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197 | (RTEMS_PRIORITY | RTEMS_BINARY_SEMAPHORE | \ |
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198 | RTEMS_INHERIT_PRIORITY | RTEMS_NO_PRIORITY_CEILING | RTEMS_LOCAL) |
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199 | |
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200 | /** |
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201 | * Waiter semaphore attributes. |
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202 | * |
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203 | * @warning Do not configure as inherit priority. If a driver is in the driver |
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204 | * initialisation table this locked semaphore will have the IDLE task |
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205 | * as the holder and a blocking task will raise the priority of the |
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206 | * IDLE task which can cause unsual side effects. |
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207 | */ |
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208 | #define RTEMS_BDBUF_CACHE_WAITER_ATTRIBS \ |
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209 | (RTEMS_PRIORITY | RTEMS_SIMPLE_BINARY_SEMAPHORE | \ |
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210 | RTEMS_NO_INHERIT_PRIORITY | RTEMS_NO_PRIORITY_CEILING | RTEMS_LOCAL) |
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211 | |
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212 | /** |
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213 | * Waiter timeout. Set to non-zero to find some info on a waiter that is |
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214 | * waiting too long. |
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215 | */ |
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216 | #define RTEMS_BDBUF_WAIT_TIMEOUT RTEMS_NO_TIMEOUT |
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217 | #if !defined (RTEMS_BDBUF_WAIT_TIMEOUT) |
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218 | #define RTEMS_BDBUF_WAIT_TIMEOUT \ |
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219 | (TOD_MICROSECONDS_TO_TICKS (20000000)) |
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220 | #endif |
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221 | |
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222 | /* |
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223 | * The swap out task. |
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224 | */ |
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225 | static rtems_task rtems_bdbuf_swapout_task(rtems_task_argument arg); |
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226 | |
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227 | /** |
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228 | * The Buffer Descriptor cache. |
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229 | */ |
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230 | static rtems_bdbuf_cache bdbuf_cache; |
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231 | |
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232 | #if RTEMS_BDBUF_TRACE |
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233 | /** |
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234 | * If true output the trace message. |
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235 | */ |
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236 | bool rtems_bdbuf_tracer; |
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237 | |
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238 | /** |
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239 | * Return the number of items on the list. |
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240 | * |
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241 | * @param list The chain control. |
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242 | * @return uint32_t The number of items on the list. |
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243 | */ |
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244 | uint32_t |
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245 | rtems_bdbuf_list_count (rtems_chain_control* list) |
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246 | { |
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247 | rtems_chain_node* node = rtems_chain_first (list); |
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248 | uint32_t count = 0; |
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249 | while (!rtems_chain_is_tail (list, node)) |
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250 | { |
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251 | count++; |
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252 | node = rtems_chain_next (node); |
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253 | } |
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254 | return count; |
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255 | } |
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256 | |
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257 | /** |
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258 | * Show the usage for the bdbuf cache. |
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259 | */ |
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260 | void |
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261 | rtems_bdbuf_show_usage (void) |
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262 | { |
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263 | uint32_t group; |
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264 | uint32_t total = 0; |
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265 | uint32_t val; |
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266 | |
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267 | for (group = 0; group < bdbuf_cache.group_count; group++) |
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268 | total += bdbuf_cache.groups[group].users; |
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269 | printf ("bdbuf:group users=%lu", total); |
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270 | val = rtems_bdbuf_list_count (&bdbuf_cache.lru); |
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271 | printf (", lru=%lu", val); |
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272 | total = val; |
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273 | val = rtems_bdbuf_list_count (&bdbuf_cache.modified); |
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274 | printf (", mod=%lu", val); |
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275 | total += val; |
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276 | val = rtems_bdbuf_list_count (&bdbuf_cache.sync); |
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277 | printf (", sync=%lu", val); |
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278 | total += val; |
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279 | printf (", total=%lu\n", total); |
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280 | } |
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281 | |
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282 | /** |
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283 | * Show the users for a group of a bd. |
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284 | * |
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285 | * @param where A label to show the context of output. |
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286 | * @param bd The bd to show the users of. |
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287 | */ |
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288 | void |
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289 | rtems_bdbuf_show_users (const char* where, rtems_bdbuf_buffer* bd) |
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290 | { |
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291 | const char* states[] = |
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292 | { "FR", "EM", "CH", "AC", "AM", "MD", "SY", "TR" }; |
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293 | |
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294 | printf ("bdbuf:users: %15s: [%" PRIu32 " (%s)] %td:%td = %" PRIu32 " %s\n", |
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295 | where, |
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296 | bd->block, states[bd->state], |
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297 | bd->group - bdbuf_cache.groups, |
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298 | bd - bdbuf_cache.bds, |
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299 | bd->group->users, |
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300 | bd->group->users > 8 ? "<<<<<<<" : ""); |
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301 | } |
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302 | #else |
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303 | #define rtems_bdbuf_tracer (0) |
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304 | #define rtems_bdbuf_show_usage() ((void) 0) |
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305 | #define rtems_bdbuf_show_users(_w, _b) ((void) 0) |
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306 | #endif |
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307 | |
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308 | /** |
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309 | * The default maximum height of 32 allows for AVL trees having between |
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310 | * 5,704,880 and 4,294,967,295 nodes, depending on order of insertion. You may |
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311 | * change this compile-time constant as you wish. |
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312 | */ |
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313 | #ifndef RTEMS_BDBUF_AVL_MAX_HEIGHT |
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314 | #define RTEMS_BDBUF_AVL_MAX_HEIGHT (32) |
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315 | #endif |
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316 | |
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317 | static void |
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318 | rtems_bdbuf_fatal (rtems_bdbuf_buf_state state, uint32_t error) |
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319 | { |
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320 | rtems_fatal_error_occurred ((((uint32_t) state) << 16) | error); |
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321 | } |
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322 | |
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323 | /** |
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324 | * Searches for the node with specified dd/block. |
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325 | * |
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326 | * @param root pointer to the root node of the AVL-Tree |
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327 | * @param dd disk device search key |
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328 | * @param block block search key |
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329 | * @retval NULL node with the specified dd/block is not found |
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330 | * @return pointer to the node with specified dd/block |
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331 | */ |
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332 | static rtems_bdbuf_buffer * |
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333 | rtems_bdbuf_avl_search (rtems_bdbuf_buffer** root, |
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334 | const rtems_disk_device *dd, |
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335 | rtems_blkdev_bnum block) |
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336 | { |
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337 | rtems_bdbuf_buffer* p = *root; |
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338 | |
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339 | while ((p != NULL) && ((p->dd != dd) || (p->block != block))) |
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340 | { |
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341 | if (((uintptr_t) p->dd < (uintptr_t) dd) |
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342 | || ((p->dd == dd) && (p->block < block))) |
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343 | { |
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344 | p = p->avl.right; |
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345 | } |
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346 | else |
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347 | { |
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348 | p = p->avl.left; |
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349 | } |
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350 | } |
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351 | |
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352 | return p; |
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353 | } |
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354 | |
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355 | /** |
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356 | * Inserts the specified node to the AVl-Tree. |
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357 | * |
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358 | * @param root pointer to the root node of the AVL-Tree |
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359 | * @param node Pointer to the node to add. |
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360 | * @retval 0 The node added successfully |
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361 | * @retval -1 An error occured |
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362 | */ |
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363 | static int |
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364 | rtems_bdbuf_avl_insert(rtems_bdbuf_buffer** root, |
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365 | rtems_bdbuf_buffer* node) |
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366 | { |
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367 | const rtems_disk_device *dd = node->dd; |
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368 | rtems_blkdev_bnum block = node->block; |
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369 | |
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370 | rtems_bdbuf_buffer* p = *root; |
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371 | rtems_bdbuf_buffer* q; |
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372 | rtems_bdbuf_buffer* p1; |
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373 | rtems_bdbuf_buffer* p2; |
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374 | rtems_bdbuf_buffer* buf_stack[RTEMS_BDBUF_AVL_MAX_HEIGHT]; |
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375 | rtems_bdbuf_buffer** buf_prev = buf_stack; |
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376 | |
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377 | bool modified = false; |
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378 | |
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379 | if (p == NULL) |
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380 | { |
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381 | *root = node; |
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382 | node->avl.left = NULL; |
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383 | node->avl.right = NULL; |
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384 | node->avl.bal = 0; |
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385 | return 0; |
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386 | } |
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387 | |
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388 | while (p != NULL) |
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389 | { |
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390 | *buf_prev++ = p; |
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391 | |
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392 | if (((uintptr_t) p->dd < (uintptr_t) dd) |
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393 | || ((p->dd == dd) && (p->block < block))) |
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394 | { |
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395 | p->avl.cache = 1; |
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396 | q = p->avl.right; |
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397 | if (q == NULL) |
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398 | { |
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399 | q = node; |
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400 | p->avl.right = q = node; |
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401 | break; |
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402 | } |
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403 | } |
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404 | else if ((p->dd != dd) || (p->block != block)) |
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405 | { |
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406 | p->avl.cache = -1; |
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407 | q = p->avl.left; |
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408 | if (q == NULL) |
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409 | { |
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410 | q = node; |
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411 | p->avl.left = q; |
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412 | break; |
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413 | } |
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414 | } |
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415 | else |
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416 | { |
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417 | return -1; |
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418 | } |
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419 | |
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420 | p = q; |
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421 | } |
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422 | |
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423 | q->avl.left = q->avl.right = NULL; |
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424 | q->avl.bal = 0; |
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425 | modified = true; |
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426 | buf_prev--; |
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427 | |
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428 | while (modified) |
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429 | { |
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430 | if (p->avl.cache == -1) |
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431 | { |
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432 | switch (p->avl.bal) |
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433 | { |
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434 | case 1: |
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435 | p->avl.bal = 0; |
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436 | modified = false; |
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437 | break; |
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438 | |
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439 | case 0: |
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440 | p->avl.bal = -1; |
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441 | break; |
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442 | |
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443 | case -1: |
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444 | p1 = p->avl.left; |
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445 | if (p1->avl.bal == -1) /* simple LL-turn */ |
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446 | { |
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447 | p->avl.left = p1->avl.right; |
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448 | p1->avl.right = p; |
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449 | p->avl.bal = 0; |
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450 | p = p1; |
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451 | } |
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452 | else /* double LR-turn */ |
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453 | { |
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454 | p2 = p1->avl.right; |
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455 | p1->avl.right = p2->avl.left; |
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456 | p2->avl.left = p1; |
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457 | p->avl.left = p2->avl.right; |
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458 | p2->avl.right = p; |
---|
459 | if (p2->avl.bal == -1) p->avl.bal = +1; else p->avl.bal = 0; |
---|
460 | if (p2->avl.bal == +1) p1->avl.bal = -1; else p1->avl.bal = 0; |
---|
461 | p = p2; |
---|
462 | } |
---|
463 | p->avl.bal = 0; |
---|
464 | modified = false; |
---|
465 | break; |
---|
466 | |
---|
467 | default: |
---|
468 | break; |
---|
469 | } |
---|
470 | } |
---|
471 | else |
---|
472 | { |
---|
473 | switch (p->avl.bal) |
---|
474 | { |
---|
475 | case -1: |
---|
476 | p->avl.bal = 0; |
---|
477 | modified = false; |
---|
478 | break; |
---|
479 | |
---|
480 | case 0: |
---|
481 | p->avl.bal = 1; |
---|
482 | break; |
---|
483 | |
---|
484 | case 1: |
---|
485 | p1 = p->avl.right; |
---|
486 | if (p1->avl.bal == 1) /* simple RR-turn */ |
---|
487 | { |
---|
488 | p->avl.right = p1->avl.left; |
---|
489 | p1->avl.left = p; |
---|
490 | p->avl.bal = 0; |
---|
491 | p = p1; |
---|
492 | } |
---|
493 | else /* double RL-turn */ |
---|
494 | { |
---|
495 | p2 = p1->avl.left; |
---|
496 | p1->avl.left = p2->avl.right; |
---|
497 | p2->avl.right = p1; |
---|
498 | p->avl.right = p2->avl.left; |
---|
499 | p2->avl.left = p; |
---|
500 | if (p2->avl.bal == +1) p->avl.bal = -1; else p->avl.bal = 0; |
---|
501 | if (p2->avl.bal == -1) p1->avl.bal = +1; else p1->avl.bal = 0; |
---|
502 | p = p2; |
---|
503 | } |
---|
504 | p->avl.bal = 0; |
---|
505 | modified = false; |
---|
506 | break; |
---|
507 | |
---|
508 | default: |
---|
509 | break; |
---|
510 | } |
---|
511 | } |
---|
512 | q = p; |
---|
513 | if (buf_prev > buf_stack) |
---|
514 | { |
---|
515 | p = *--buf_prev; |
---|
516 | |
---|
517 | if (p->avl.cache == -1) |
---|
518 | { |
---|
519 | p->avl.left = q; |
---|
520 | } |
---|
521 | else |
---|
522 | { |
---|
523 | p->avl.right = q; |
---|
524 | } |
---|
525 | } |
---|
526 | else |
---|
527 | { |
---|
528 | *root = p; |
---|
529 | break; |
---|
530 | } |
---|
531 | }; |
---|
532 | |
---|
533 | return 0; |
---|
534 | } |
---|
535 | |
---|
536 | |
---|
537 | /** |
---|
538 | * Removes the node from the tree. |
---|
539 | * |
---|
540 | * @param root Pointer to pointer to the root node |
---|
541 | * @param node Pointer to the node to remove |
---|
542 | * @retval 0 Item removed |
---|
543 | * @retval -1 No such item found |
---|
544 | */ |
---|
545 | static int |
---|
546 | rtems_bdbuf_avl_remove(rtems_bdbuf_buffer** root, |
---|
547 | const rtems_bdbuf_buffer* node) |
---|
548 | { |
---|
549 | const rtems_disk_device *dd = node->dd; |
---|
550 | rtems_blkdev_bnum block = node->block; |
---|
551 | |
---|
552 | rtems_bdbuf_buffer* p = *root; |
---|
553 | rtems_bdbuf_buffer* q; |
---|
554 | rtems_bdbuf_buffer* r; |
---|
555 | rtems_bdbuf_buffer* s; |
---|
556 | rtems_bdbuf_buffer* p1; |
---|
557 | rtems_bdbuf_buffer* p2; |
---|
558 | rtems_bdbuf_buffer* buf_stack[RTEMS_BDBUF_AVL_MAX_HEIGHT]; |
---|
559 | rtems_bdbuf_buffer** buf_prev = buf_stack; |
---|
560 | |
---|
561 | bool modified = false; |
---|
562 | |
---|
563 | memset (buf_stack, 0, sizeof(buf_stack)); |
---|
564 | |
---|
565 | while (p != NULL) |
---|
566 | { |
---|
567 | *buf_prev++ = p; |
---|
568 | |
---|
569 | if (((uintptr_t) p->dd < (uintptr_t) dd) |
---|
570 | || ((p->dd == dd) && (p->block < block))) |
---|
571 | { |
---|
572 | p->avl.cache = 1; |
---|
573 | p = p->avl.right; |
---|
574 | } |
---|
575 | else if ((p->dd != dd) || (p->block != block)) |
---|
576 | { |
---|
577 | p->avl.cache = -1; |
---|
578 | p = p->avl.left; |
---|
579 | } |
---|
580 | else |
---|
581 | { |
---|
582 | /* node found */ |
---|
583 | break; |
---|
584 | } |
---|
585 | } |
---|
586 | |
---|
587 | if (p == NULL) |
---|
588 | { |
---|
589 | /* there is no such node */ |
---|
590 | return -1; |
---|
591 | } |
---|
592 | |
---|
593 | q = p; |
---|
594 | |
---|
595 | buf_prev--; |
---|
596 | if (buf_prev > buf_stack) |
---|
597 | { |
---|
598 | p = *(buf_prev - 1); |
---|
599 | } |
---|
600 | else |
---|
601 | { |
---|
602 | p = NULL; |
---|
603 | } |
---|
604 | |
---|
605 | /* at this moment q - is a node to delete, p is q's parent */ |
---|
606 | if (q->avl.right == NULL) |
---|
607 | { |
---|
608 | r = q->avl.left; |
---|
609 | if (r != NULL) |
---|
610 | { |
---|
611 | r->avl.bal = 0; |
---|
612 | } |
---|
613 | q = r; |
---|
614 | } |
---|
615 | else |
---|
616 | { |
---|
617 | rtems_bdbuf_buffer **t; |
---|
618 | |
---|
619 | r = q->avl.right; |
---|
620 | |
---|
621 | if (r->avl.left == NULL) |
---|
622 | { |
---|
623 | r->avl.left = q->avl.left; |
---|
624 | r->avl.bal = q->avl.bal; |
---|
625 | r->avl.cache = 1; |
---|
626 | *buf_prev++ = q = r; |
---|
627 | } |
---|
628 | else |
---|
629 | { |
---|
630 | t = buf_prev++; |
---|
631 | s = r; |
---|
632 | |
---|
633 | while (s->avl.left != NULL) |
---|
634 | { |
---|
635 | *buf_prev++ = r = s; |
---|
636 | s = r->avl.left; |
---|
637 | r->avl.cache = -1; |
---|
638 | } |
---|
639 | |
---|
640 | s->avl.left = q->avl.left; |
---|
641 | r->avl.left = s->avl.right; |
---|
642 | s->avl.right = q->avl.right; |
---|
643 | s->avl.bal = q->avl.bal; |
---|
644 | s->avl.cache = 1; |
---|
645 | |
---|
646 | *t = q = s; |
---|
647 | } |
---|
648 | } |
---|
649 | |
---|
650 | if (p != NULL) |
---|
651 | { |
---|
652 | if (p->avl.cache == -1) |
---|
653 | { |
---|
654 | p->avl.left = q; |
---|
655 | } |
---|
656 | else |
---|
657 | { |
---|
658 | p->avl.right = q; |
---|
659 | } |
---|
660 | } |
---|
661 | else |
---|
662 | { |
---|
663 | *root = q; |
---|
664 | } |
---|
665 | |
---|
666 | modified = true; |
---|
667 | |
---|
668 | while (modified) |
---|
669 | { |
---|
670 | if (buf_prev > buf_stack) |
---|
671 | { |
---|
672 | p = *--buf_prev; |
---|
673 | } |
---|
674 | else |
---|
675 | { |
---|
676 | break; |
---|
677 | } |
---|
678 | |
---|
679 | if (p->avl.cache == -1) |
---|
680 | { |
---|
681 | /* rebalance left branch */ |
---|
682 | switch (p->avl.bal) |
---|
683 | { |
---|
684 | case -1: |
---|
685 | p->avl.bal = 0; |
---|
686 | break; |
---|
687 | case 0: |
---|
688 | p->avl.bal = 1; |
---|
689 | modified = false; |
---|
690 | break; |
---|
691 | |
---|
692 | case +1: |
---|
693 | p1 = p->avl.right; |
---|
694 | |
---|
695 | if (p1->avl.bal >= 0) /* simple RR-turn */ |
---|
696 | { |
---|
697 | p->avl.right = p1->avl.left; |
---|
698 | p1->avl.left = p; |
---|
699 | |
---|
700 | if (p1->avl.bal == 0) |
---|
701 | { |
---|
702 | p1->avl.bal = -1; |
---|
703 | modified = false; |
---|
704 | } |
---|
705 | else |
---|
706 | { |
---|
707 | p->avl.bal = 0; |
---|
708 | p1->avl.bal = 0; |
---|
709 | } |
---|
710 | p = p1; |
---|
711 | } |
---|
712 | else /* double RL-turn */ |
---|
713 | { |
---|
714 | p2 = p1->avl.left; |
---|
715 | |
---|
716 | p1->avl.left = p2->avl.right; |
---|
717 | p2->avl.right = p1; |
---|
718 | p->avl.right = p2->avl.left; |
---|
719 | p2->avl.left = p; |
---|
720 | |
---|
721 | if (p2->avl.bal == +1) p->avl.bal = -1; else p->avl.bal = 0; |
---|
722 | if (p2->avl.bal == -1) p1->avl.bal = 1; else p1->avl.bal = 0; |
---|
723 | |
---|
724 | p = p2; |
---|
725 | p2->avl.bal = 0; |
---|
726 | } |
---|
727 | break; |
---|
728 | |
---|
729 | default: |
---|
730 | break; |
---|
731 | } |
---|
732 | } |
---|
733 | else |
---|
734 | { |
---|
735 | /* rebalance right branch */ |
---|
736 | switch (p->avl.bal) |
---|
737 | { |
---|
738 | case +1: |
---|
739 | p->avl.bal = 0; |
---|
740 | break; |
---|
741 | |
---|
742 | case 0: |
---|
743 | p->avl.bal = -1; |
---|
744 | modified = false; |
---|
745 | break; |
---|
746 | |
---|
747 | case -1: |
---|
748 | p1 = p->avl.left; |
---|
749 | |
---|
750 | if (p1->avl.bal <= 0) /* simple LL-turn */ |
---|
751 | { |
---|
752 | p->avl.left = p1->avl.right; |
---|
753 | p1->avl.right = p; |
---|
754 | if (p1->avl.bal == 0) |
---|
755 | { |
---|
756 | p1->avl.bal = 1; |
---|
757 | modified = false; |
---|
758 | } |
---|
759 | else |
---|
760 | { |
---|
761 | p->avl.bal = 0; |
---|
762 | p1->avl.bal = 0; |
---|
763 | } |
---|
764 | p = p1; |
---|
765 | } |
---|
766 | else /* double LR-turn */ |
---|
767 | { |
---|
768 | p2 = p1->avl.right; |
---|
769 | |
---|
770 | p1->avl.right = p2->avl.left; |
---|
771 | p2->avl.left = p1; |
---|
772 | p->avl.left = p2->avl.right; |
---|
773 | p2->avl.right = p; |
---|
774 | |
---|
775 | if (p2->avl.bal == -1) p->avl.bal = 1; else p->avl.bal = 0; |
---|
776 | if (p2->avl.bal == +1) p1->avl.bal = -1; else p1->avl.bal = 0; |
---|
777 | |
---|
778 | p = p2; |
---|
779 | p2->avl.bal = 0; |
---|
780 | } |
---|
781 | break; |
---|
782 | |
---|
783 | default: |
---|
784 | break; |
---|
785 | } |
---|
786 | } |
---|
787 | |
---|
788 | if (buf_prev > buf_stack) |
---|
789 | { |
---|
790 | q = *(buf_prev - 1); |
---|
791 | |
---|
792 | if (q->avl.cache == -1) |
---|
793 | { |
---|
794 | q->avl.left = p; |
---|
795 | } |
---|
796 | else |
---|
797 | { |
---|
798 | q->avl.right = p; |
---|
799 | } |
---|
800 | } |
---|
801 | else |
---|
802 | { |
---|
803 | *root = p; |
---|
804 | break; |
---|
805 | } |
---|
806 | |
---|
807 | } |
---|
808 | |
---|
809 | return 0; |
---|
810 | } |
---|
811 | |
---|
812 | static void |
---|
813 | rtems_bdbuf_set_state (rtems_bdbuf_buffer *bd, rtems_bdbuf_buf_state state) |
---|
814 | { |
---|
815 | bd->state = state; |
---|
816 | } |
---|
817 | |
---|
818 | static rtems_blkdev_bnum |
---|
819 | rtems_bdbuf_media_block (const rtems_disk_device *dd, rtems_blkdev_bnum block) |
---|
820 | { |
---|
821 | if (dd->block_to_media_block_shift >= 0) |
---|
822 | return block << dd->block_to_media_block_shift; |
---|
823 | else |
---|
824 | /* |
---|
825 | * Change the block number for the block size to the block number for the media |
---|
826 | * block size. We have to use 64bit maths. There is no short cut here. |
---|
827 | */ |
---|
828 | return (rtems_blkdev_bnum) |
---|
829 | ((((uint64_t) block) * dd->block_size) / dd->media_block_size); |
---|
830 | } |
---|
831 | |
---|
832 | /** |
---|
833 | * Lock the mutex. A single task can nest calls. |
---|
834 | * |
---|
835 | * @param lock The mutex to lock. |
---|
836 | * @param fatal_error_code The error code if the call fails. |
---|
837 | */ |
---|
838 | static void |
---|
839 | rtems_bdbuf_lock (rtems_id lock, uint32_t fatal_error_code) |
---|
840 | { |
---|
841 | rtems_status_code sc = rtems_semaphore_obtain (lock, |
---|
842 | RTEMS_WAIT, |
---|
843 | RTEMS_NO_TIMEOUT); |
---|
844 | if (sc != RTEMS_SUCCESSFUL) |
---|
845 | rtems_fatal_error_occurred (fatal_error_code); |
---|
846 | } |
---|
847 | |
---|
848 | /** |
---|
849 | * Unlock the mutex. |
---|
850 | * |
---|
851 | * @param lock The mutex to unlock. |
---|
852 | * @param fatal_error_code The error code if the call fails. |
---|
853 | */ |
---|
854 | static void |
---|
855 | rtems_bdbuf_unlock (rtems_id lock, uint32_t fatal_error_code) |
---|
856 | { |
---|
857 | rtems_status_code sc = rtems_semaphore_release (lock); |
---|
858 | if (sc != RTEMS_SUCCESSFUL) |
---|
859 | rtems_fatal_error_occurred (fatal_error_code); |
---|
860 | } |
---|
861 | |
---|
862 | /** |
---|
863 | * Lock the cache. A single task can nest calls. |
---|
864 | */ |
---|
865 | static void |
---|
866 | rtems_bdbuf_lock_cache (void) |
---|
867 | { |
---|
868 | rtems_bdbuf_lock (bdbuf_cache.lock, RTEMS_BLKDEV_FATAL_BDBUF_CACHE_LOCK); |
---|
869 | } |
---|
870 | |
---|
871 | /** |
---|
872 | * Unlock the cache. |
---|
873 | */ |
---|
874 | static void |
---|
875 | rtems_bdbuf_unlock_cache (void) |
---|
876 | { |
---|
877 | rtems_bdbuf_unlock (bdbuf_cache.lock, RTEMS_BLKDEV_FATAL_BDBUF_CACHE_UNLOCK); |
---|
878 | } |
---|
879 | |
---|
880 | /** |
---|
881 | * Lock the cache's sync. A single task can nest calls. |
---|
882 | */ |
---|
883 | static void |
---|
884 | rtems_bdbuf_lock_sync (void) |
---|
885 | { |
---|
886 | rtems_bdbuf_lock (bdbuf_cache.sync_lock, RTEMS_BLKDEV_FATAL_BDBUF_SYNC_LOCK); |
---|
887 | } |
---|
888 | |
---|
889 | /** |
---|
890 | * Unlock the cache's sync lock. Any blocked writers are woken. |
---|
891 | */ |
---|
892 | static void |
---|
893 | rtems_bdbuf_unlock_sync (void) |
---|
894 | { |
---|
895 | rtems_bdbuf_unlock (bdbuf_cache.sync_lock, |
---|
896 | RTEMS_BLKDEV_FATAL_BDBUF_SYNC_UNLOCK); |
---|
897 | } |
---|
898 | |
---|
899 | static void |
---|
900 | rtems_bdbuf_group_obtain (rtems_bdbuf_buffer *bd) |
---|
901 | { |
---|
902 | ++bd->group->users; |
---|
903 | } |
---|
904 | |
---|
905 | static void |
---|
906 | rtems_bdbuf_group_release (rtems_bdbuf_buffer *bd) |
---|
907 | { |
---|
908 | --bd->group->users; |
---|
909 | } |
---|
910 | |
---|
911 | static rtems_mode |
---|
912 | rtems_bdbuf_disable_preemption (void) |
---|
913 | { |
---|
914 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
915 | rtems_mode prev_mode = 0; |
---|
916 | |
---|
917 | sc = rtems_task_mode (RTEMS_NO_PREEMPT, RTEMS_PREEMPT_MASK, &prev_mode); |
---|
918 | if (sc != RTEMS_SUCCESSFUL) |
---|
919 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_PREEMPT_DIS); |
---|
920 | |
---|
921 | return prev_mode; |
---|
922 | } |
---|
923 | |
---|
924 | static void |
---|
925 | rtems_bdbuf_restore_preemption (rtems_mode prev_mode) |
---|
926 | { |
---|
927 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
928 | |
---|
929 | sc = rtems_task_mode (prev_mode, RTEMS_ALL_MODE_MASKS, &prev_mode); |
---|
930 | if (sc != RTEMS_SUCCESSFUL) |
---|
931 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_PREEMPT_RST); |
---|
932 | } |
---|
933 | |
---|
934 | /** |
---|
935 | * Wait until woken. Semaphores are used so a number of tasks can wait and can |
---|
936 | * be woken at once. Task events would require we maintain a list of tasks to |
---|
937 | * be woken and this would require storage and we do not know the number of |
---|
938 | * tasks that could be waiting. |
---|
939 | * |
---|
940 | * While we have the cache locked we can try and claim the semaphore and |
---|
941 | * therefore know when we release the lock to the cache we will block until the |
---|
942 | * semaphore is released. This may even happen before we get to block. |
---|
943 | * |
---|
944 | * A counter is used to save the release call when no one is waiting. |
---|
945 | * |
---|
946 | * The function assumes the cache is locked on entry and it will be locked on |
---|
947 | * exit. |
---|
948 | */ |
---|
949 | static void |
---|
950 | rtems_bdbuf_anonymous_wait (rtems_bdbuf_waiters *waiters) |
---|
951 | { |
---|
952 | rtems_status_code sc; |
---|
953 | rtems_mode prev_mode; |
---|
954 | |
---|
955 | /* |
---|
956 | * Indicate we are waiting. |
---|
957 | */ |
---|
958 | ++waiters->count; |
---|
959 | |
---|
960 | /* |
---|
961 | * Disable preemption then unlock the cache and block. There is no POSIX |
---|
962 | * condition variable in the core API so this is a work around. |
---|
963 | * |
---|
964 | * The issue is a task could preempt after the cache is unlocked because it is |
---|
965 | * blocking or just hits that window, and before this task has blocked on the |
---|
966 | * semaphore. If the preempting task flushes the queue this task will not see |
---|
967 | * the flush and may block for ever or until another transaction flushes this |
---|
968 | * semaphore. |
---|
969 | */ |
---|
970 | prev_mode = rtems_bdbuf_disable_preemption (); |
---|
971 | |
---|
972 | /* |
---|
973 | * Unlock the cache, wait, and lock the cache when we return. |
---|
974 | */ |
---|
975 | rtems_bdbuf_unlock_cache (); |
---|
976 | |
---|
977 | sc = rtems_semaphore_obtain (waiters->sema, RTEMS_WAIT, RTEMS_BDBUF_WAIT_TIMEOUT); |
---|
978 | |
---|
979 | if (sc == RTEMS_TIMEOUT) |
---|
980 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_CACHE_WAIT_TO); |
---|
981 | |
---|
982 | if (sc != RTEMS_UNSATISFIED) |
---|
983 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_CACHE_WAIT_2); |
---|
984 | |
---|
985 | rtems_bdbuf_lock_cache (); |
---|
986 | |
---|
987 | rtems_bdbuf_restore_preemption (prev_mode); |
---|
988 | |
---|
989 | --waiters->count; |
---|
990 | } |
---|
991 | |
---|
992 | static void |
---|
993 | rtems_bdbuf_wait (rtems_bdbuf_buffer *bd, rtems_bdbuf_waiters *waiters) |
---|
994 | { |
---|
995 | rtems_bdbuf_group_obtain (bd); |
---|
996 | ++bd->waiters; |
---|
997 | rtems_bdbuf_anonymous_wait (waiters); |
---|
998 | --bd->waiters; |
---|
999 | rtems_bdbuf_group_release (bd); |
---|
1000 | } |
---|
1001 | |
---|
1002 | /** |
---|
1003 | * Wake a blocked resource. The resource has a counter that lets us know if |
---|
1004 | * there are any waiters. |
---|
1005 | */ |
---|
1006 | static void |
---|
1007 | rtems_bdbuf_wake (const rtems_bdbuf_waiters *waiters) |
---|
1008 | { |
---|
1009 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
1010 | |
---|
1011 | if (waiters->count > 0) |
---|
1012 | { |
---|
1013 | sc = rtems_semaphore_flush (waiters->sema); |
---|
1014 | if (sc != RTEMS_SUCCESSFUL) |
---|
1015 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_CACHE_WAKE); |
---|
1016 | } |
---|
1017 | } |
---|
1018 | |
---|
1019 | static void |
---|
1020 | rtems_bdbuf_wake_swapper (void) |
---|
1021 | { |
---|
1022 | rtems_status_code sc = rtems_event_send (bdbuf_cache.swapout, |
---|
1023 | RTEMS_BDBUF_SWAPOUT_SYNC); |
---|
1024 | if (sc != RTEMS_SUCCESSFUL) |
---|
1025 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_SO_WAKE); |
---|
1026 | } |
---|
1027 | |
---|
1028 | static bool |
---|
1029 | rtems_bdbuf_has_buffer_waiters (void) |
---|
1030 | { |
---|
1031 | return bdbuf_cache.buffer_waiters.count; |
---|
1032 | } |
---|
1033 | |
---|
1034 | static void |
---|
1035 | rtems_bdbuf_remove_from_tree (rtems_bdbuf_buffer *bd) |
---|
1036 | { |
---|
1037 | if (rtems_bdbuf_avl_remove (&bdbuf_cache.tree, bd) != 0) |
---|
1038 | rtems_bdbuf_fatal (bd->state, RTEMS_BLKDEV_FATAL_BDBUF_TREE_RM); |
---|
1039 | } |
---|
1040 | |
---|
1041 | static void |
---|
1042 | rtems_bdbuf_remove_from_tree_and_lru_list (rtems_bdbuf_buffer *bd) |
---|
1043 | { |
---|
1044 | switch (bd->state) |
---|
1045 | { |
---|
1046 | case RTEMS_BDBUF_STATE_FREE: |
---|
1047 | break; |
---|
1048 | case RTEMS_BDBUF_STATE_CACHED: |
---|
1049 | rtems_bdbuf_remove_from_tree (bd); |
---|
1050 | break; |
---|
1051 | default: |
---|
1052 | rtems_bdbuf_fatal (bd->state, RTEMS_BLKDEV_FATAL_BDBUF_STATE_10); |
---|
1053 | } |
---|
1054 | |
---|
1055 | rtems_chain_extract_unprotected (&bd->link); |
---|
1056 | } |
---|
1057 | |
---|
1058 | static void |
---|
1059 | rtems_bdbuf_make_free_and_add_to_lru_list (rtems_bdbuf_buffer *bd) |
---|
1060 | { |
---|
1061 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_FREE); |
---|
1062 | rtems_chain_prepend_unprotected (&bdbuf_cache.lru, &bd->link); |
---|
1063 | } |
---|
1064 | |
---|
1065 | static void |
---|
1066 | rtems_bdbuf_make_empty (rtems_bdbuf_buffer *bd) |
---|
1067 | { |
---|
1068 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_EMPTY); |
---|
1069 | } |
---|
1070 | |
---|
1071 | static void |
---|
1072 | rtems_bdbuf_make_cached_and_add_to_lru_list (rtems_bdbuf_buffer *bd) |
---|
1073 | { |
---|
1074 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_CACHED); |
---|
1075 | rtems_chain_append_unprotected (&bdbuf_cache.lru, &bd->link); |
---|
1076 | } |
---|
1077 | |
---|
1078 | static void |
---|
1079 | rtems_bdbuf_discard_buffer (rtems_bdbuf_buffer *bd) |
---|
1080 | { |
---|
1081 | rtems_bdbuf_make_empty (bd); |
---|
1082 | |
---|
1083 | if (bd->waiters == 0) |
---|
1084 | { |
---|
1085 | rtems_bdbuf_remove_from_tree (bd); |
---|
1086 | rtems_bdbuf_make_free_and_add_to_lru_list (bd); |
---|
1087 | } |
---|
1088 | } |
---|
1089 | |
---|
1090 | static void |
---|
1091 | rtems_bdbuf_add_to_modified_list_after_access (rtems_bdbuf_buffer *bd) |
---|
1092 | { |
---|
1093 | if (bdbuf_cache.sync_active && bdbuf_cache.sync_device == bd->dd) |
---|
1094 | { |
---|
1095 | rtems_bdbuf_unlock_cache (); |
---|
1096 | |
---|
1097 | /* |
---|
1098 | * Wait for the sync lock. |
---|
1099 | */ |
---|
1100 | rtems_bdbuf_lock_sync (); |
---|
1101 | |
---|
1102 | rtems_bdbuf_unlock_sync (); |
---|
1103 | rtems_bdbuf_lock_cache (); |
---|
1104 | } |
---|
1105 | |
---|
1106 | /* |
---|
1107 | * Only the first modified release sets the timer and any further user |
---|
1108 | * accesses do not change the timer value which should move down. This |
---|
1109 | * assumes the user's hold of the buffer is much less than the time on the |
---|
1110 | * modified list. Resetting the timer on each access which could result in a |
---|
1111 | * buffer never getting to 0 and never being forced onto disk. This raises a |
---|
1112 | * difficult question. Is a snapshot of a block that is changing better than |
---|
1113 | * nothing being written? We have tended to think we should hold changes for |
---|
1114 | * only a specific period of time even if still changing and get onto disk |
---|
1115 | * and letting the file system try and recover this position if it can. |
---|
1116 | */ |
---|
1117 | if (bd->state == RTEMS_BDBUF_STATE_ACCESS_CACHED |
---|
1118 | || bd->state == RTEMS_BDBUF_STATE_ACCESS_EMPTY) |
---|
1119 | bd->hold_timer = bdbuf_config.swap_block_hold; |
---|
1120 | |
---|
1121 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_MODIFIED); |
---|
1122 | rtems_chain_append_unprotected (&bdbuf_cache.modified, &bd->link); |
---|
1123 | |
---|
1124 | if (bd->waiters) |
---|
1125 | rtems_bdbuf_wake (&bdbuf_cache.access_waiters); |
---|
1126 | else if (rtems_bdbuf_has_buffer_waiters ()) |
---|
1127 | rtems_bdbuf_wake_swapper (); |
---|
1128 | } |
---|
1129 | |
---|
1130 | static void |
---|
1131 | rtems_bdbuf_add_to_lru_list_after_access (rtems_bdbuf_buffer *bd) |
---|
1132 | { |
---|
1133 | rtems_bdbuf_group_release (bd); |
---|
1134 | rtems_bdbuf_make_cached_and_add_to_lru_list (bd); |
---|
1135 | |
---|
1136 | if (bd->waiters) |
---|
1137 | rtems_bdbuf_wake (&bdbuf_cache.access_waiters); |
---|
1138 | else |
---|
1139 | rtems_bdbuf_wake (&bdbuf_cache.buffer_waiters); |
---|
1140 | } |
---|
1141 | |
---|
1142 | /** |
---|
1143 | * Compute the number of BDs per group for a given buffer size. |
---|
1144 | * |
---|
1145 | * @param size The buffer size. It can be any size and we scale up. |
---|
1146 | */ |
---|
1147 | static size_t |
---|
1148 | rtems_bdbuf_bds_per_group (size_t size) |
---|
1149 | { |
---|
1150 | size_t bufs_per_size; |
---|
1151 | size_t bds_per_size; |
---|
1152 | |
---|
1153 | if (size > bdbuf_config.buffer_max) |
---|
1154 | return 0; |
---|
1155 | |
---|
1156 | bufs_per_size = ((size - 1) / bdbuf_config.buffer_min) + 1; |
---|
1157 | |
---|
1158 | for (bds_per_size = 1; |
---|
1159 | bds_per_size < bufs_per_size; |
---|
1160 | bds_per_size <<= 1) |
---|
1161 | ; |
---|
1162 | |
---|
1163 | return bdbuf_cache.max_bds_per_group / bds_per_size; |
---|
1164 | } |
---|
1165 | |
---|
1166 | static void |
---|
1167 | rtems_bdbuf_discard_buffer_after_access (rtems_bdbuf_buffer *bd) |
---|
1168 | { |
---|
1169 | rtems_bdbuf_group_release (bd); |
---|
1170 | rtems_bdbuf_discard_buffer (bd); |
---|
1171 | |
---|
1172 | if (bd->waiters) |
---|
1173 | rtems_bdbuf_wake (&bdbuf_cache.access_waiters); |
---|
1174 | else |
---|
1175 | rtems_bdbuf_wake (&bdbuf_cache.buffer_waiters); |
---|
1176 | } |
---|
1177 | |
---|
1178 | /** |
---|
1179 | * Reallocate a group. The BDs currently allocated in the group are removed |
---|
1180 | * from the ALV tree and any lists then the new BD's are prepended to the ready |
---|
1181 | * list of the cache. |
---|
1182 | * |
---|
1183 | * @param group The group to reallocate. |
---|
1184 | * @param new_bds_per_group The new count of BDs per group. |
---|
1185 | * @return A buffer of this group. |
---|
1186 | */ |
---|
1187 | static rtems_bdbuf_buffer * |
---|
1188 | rtems_bdbuf_group_realloc (rtems_bdbuf_group* group, size_t new_bds_per_group) |
---|
1189 | { |
---|
1190 | rtems_bdbuf_buffer* bd; |
---|
1191 | size_t b; |
---|
1192 | size_t bufs_per_bd; |
---|
1193 | |
---|
1194 | if (rtems_bdbuf_tracer) |
---|
1195 | printf ("bdbuf:realloc: %tu: %zd -> %zd\n", |
---|
1196 | group - bdbuf_cache.groups, group->bds_per_group, |
---|
1197 | new_bds_per_group); |
---|
1198 | |
---|
1199 | bufs_per_bd = bdbuf_cache.max_bds_per_group / group->bds_per_group; |
---|
1200 | |
---|
1201 | for (b = 0, bd = group->bdbuf; |
---|
1202 | b < group->bds_per_group; |
---|
1203 | b++, bd += bufs_per_bd) |
---|
1204 | rtems_bdbuf_remove_from_tree_and_lru_list (bd); |
---|
1205 | |
---|
1206 | group->bds_per_group = new_bds_per_group; |
---|
1207 | bufs_per_bd = bdbuf_cache.max_bds_per_group / new_bds_per_group; |
---|
1208 | |
---|
1209 | for (b = 1, bd = group->bdbuf + bufs_per_bd; |
---|
1210 | b < group->bds_per_group; |
---|
1211 | b++, bd += bufs_per_bd) |
---|
1212 | rtems_bdbuf_make_free_and_add_to_lru_list (bd); |
---|
1213 | |
---|
1214 | if (b > 1) |
---|
1215 | rtems_bdbuf_wake (&bdbuf_cache.buffer_waiters); |
---|
1216 | |
---|
1217 | return group->bdbuf; |
---|
1218 | } |
---|
1219 | |
---|
1220 | static void |
---|
1221 | rtems_bdbuf_setup_empty_buffer (rtems_bdbuf_buffer *bd, |
---|
1222 | const rtems_disk_device *dd, |
---|
1223 | rtems_blkdev_bnum block) |
---|
1224 | { |
---|
1225 | bd->dd = dd ; |
---|
1226 | bd->block = block; |
---|
1227 | bd->avl.left = NULL; |
---|
1228 | bd->avl.right = NULL; |
---|
1229 | bd->waiters = 0; |
---|
1230 | |
---|
1231 | if (rtems_bdbuf_avl_insert (&bdbuf_cache.tree, bd) != 0) |
---|
1232 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_RECYCLE); |
---|
1233 | |
---|
1234 | rtems_bdbuf_make_empty (bd); |
---|
1235 | } |
---|
1236 | |
---|
1237 | static rtems_bdbuf_buffer * |
---|
1238 | rtems_bdbuf_get_buffer_from_lru_list (const rtems_disk_device *dd, |
---|
1239 | rtems_blkdev_bnum block, |
---|
1240 | size_t bds_per_group) |
---|
1241 | { |
---|
1242 | rtems_chain_node *node = rtems_chain_first (&bdbuf_cache.lru); |
---|
1243 | |
---|
1244 | while (!rtems_chain_is_tail (&bdbuf_cache.lru, node)) |
---|
1245 | { |
---|
1246 | rtems_bdbuf_buffer *bd = (rtems_bdbuf_buffer *) node; |
---|
1247 | rtems_bdbuf_buffer *empty_bd = NULL; |
---|
1248 | |
---|
1249 | if (rtems_bdbuf_tracer) |
---|
1250 | printf ("bdbuf:next-bd: %tu (%td:%" PRId32 ") %zd -> %zd\n", |
---|
1251 | bd - bdbuf_cache.bds, |
---|
1252 | bd->group - bdbuf_cache.groups, bd->group->users, |
---|
1253 | bd->group->bds_per_group, bds_per_group); |
---|
1254 | |
---|
1255 | /* |
---|
1256 | * If nobody waits for this BD, we may recycle it. |
---|
1257 | */ |
---|
1258 | if (bd->waiters == 0) |
---|
1259 | { |
---|
1260 | if (bd->group->bds_per_group == bds_per_group) |
---|
1261 | { |
---|
1262 | rtems_bdbuf_remove_from_tree_and_lru_list (bd); |
---|
1263 | |
---|
1264 | empty_bd = bd; |
---|
1265 | } |
---|
1266 | else if (bd->group->users == 0) |
---|
1267 | empty_bd = rtems_bdbuf_group_realloc (bd->group, bds_per_group); |
---|
1268 | } |
---|
1269 | |
---|
1270 | if (empty_bd != NULL) |
---|
1271 | { |
---|
1272 | rtems_bdbuf_setup_empty_buffer (empty_bd, dd, block); |
---|
1273 | |
---|
1274 | return empty_bd; |
---|
1275 | } |
---|
1276 | |
---|
1277 | node = rtems_chain_next (node); |
---|
1278 | } |
---|
1279 | |
---|
1280 | return NULL; |
---|
1281 | } |
---|
1282 | |
---|
1283 | /** |
---|
1284 | * Initialise the cache. |
---|
1285 | * |
---|
1286 | * @return rtems_status_code The initialisation status. |
---|
1287 | */ |
---|
1288 | rtems_status_code |
---|
1289 | rtems_bdbuf_init (void) |
---|
1290 | { |
---|
1291 | rtems_bdbuf_group* group; |
---|
1292 | rtems_bdbuf_buffer* bd; |
---|
1293 | uint8_t* buffer; |
---|
1294 | size_t b; |
---|
1295 | size_t cache_aligment; |
---|
1296 | rtems_status_code sc; |
---|
1297 | rtems_mode prev_mode; |
---|
1298 | |
---|
1299 | if (rtems_bdbuf_tracer) |
---|
1300 | printf ("bdbuf:init\n"); |
---|
1301 | |
---|
1302 | if (rtems_interrupt_is_in_progress()) |
---|
1303 | return RTEMS_CALLED_FROM_ISR; |
---|
1304 | |
---|
1305 | /* |
---|
1306 | * Check the configuration table values. |
---|
1307 | */ |
---|
1308 | if ((bdbuf_config.buffer_max % bdbuf_config.buffer_min) != 0) |
---|
1309 | return RTEMS_INVALID_NUMBER; |
---|
1310 | |
---|
1311 | /* |
---|
1312 | * We use a special variable to manage the initialisation incase we have |
---|
1313 | * completing threads doing this. You may get errors if the another thread |
---|
1314 | * makes a call and we have not finished initialisation. |
---|
1315 | */ |
---|
1316 | prev_mode = rtems_bdbuf_disable_preemption (); |
---|
1317 | if (bdbuf_cache.initialised) |
---|
1318 | { |
---|
1319 | rtems_bdbuf_restore_preemption (prev_mode); |
---|
1320 | return RTEMS_RESOURCE_IN_USE; |
---|
1321 | } |
---|
1322 | |
---|
1323 | memset(&bdbuf_cache, 0, sizeof(bdbuf_cache)); |
---|
1324 | bdbuf_cache.initialised = true; |
---|
1325 | rtems_bdbuf_restore_preemption (prev_mode); |
---|
1326 | |
---|
1327 | /* |
---|
1328 | * For unspecified cache alignments we use the CPU alignment. |
---|
1329 | */ |
---|
1330 | cache_aligment = 32; /* FIXME rtems_cache_get_data_line_size() */ |
---|
1331 | if (cache_aligment <= 0) |
---|
1332 | cache_aligment = CPU_ALIGNMENT; |
---|
1333 | |
---|
1334 | bdbuf_cache.sync_device = BDBUF_INVALID_DEV; |
---|
1335 | |
---|
1336 | rtems_chain_initialize_empty (&bdbuf_cache.swapout_workers); |
---|
1337 | rtems_chain_initialize_empty (&bdbuf_cache.lru); |
---|
1338 | rtems_chain_initialize_empty (&bdbuf_cache.modified); |
---|
1339 | rtems_chain_initialize_empty (&bdbuf_cache.sync); |
---|
1340 | |
---|
1341 | /* |
---|
1342 | * Create the locks for the cache. |
---|
1343 | */ |
---|
1344 | sc = rtems_semaphore_create (rtems_build_name ('B', 'D', 'C', 'l'), |
---|
1345 | 1, RTEMS_BDBUF_CACHE_LOCK_ATTRIBS, 0, |
---|
1346 | &bdbuf_cache.lock); |
---|
1347 | if (sc != RTEMS_SUCCESSFUL) |
---|
1348 | goto error; |
---|
1349 | |
---|
1350 | rtems_bdbuf_lock_cache (); |
---|
1351 | |
---|
1352 | sc = rtems_semaphore_create (rtems_build_name ('B', 'D', 'C', 's'), |
---|
1353 | 1, RTEMS_BDBUF_CACHE_LOCK_ATTRIBS, 0, |
---|
1354 | &bdbuf_cache.sync_lock); |
---|
1355 | if (sc != RTEMS_SUCCESSFUL) |
---|
1356 | goto error; |
---|
1357 | |
---|
1358 | sc = rtems_semaphore_create (rtems_build_name ('B', 'D', 'C', 'a'), |
---|
1359 | 0, RTEMS_BDBUF_CACHE_WAITER_ATTRIBS, 0, |
---|
1360 | &bdbuf_cache.access_waiters.sema); |
---|
1361 | if (sc != RTEMS_SUCCESSFUL) |
---|
1362 | goto error; |
---|
1363 | |
---|
1364 | sc = rtems_semaphore_create (rtems_build_name ('B', 'D', 'C', 't'), |
---|
1365 | 0, RTEMS_BDBUF_CACHE_WAITER_ATTRIBS, 0, |
---|
1366 | &bdbuf_cache.transfer_waiters.sema); |
---|
1367 | if (sc != RTEMS_SUCCESSFUL) |
---|
1368 | goto error; |
---|
1369 | |
---|
1370 | sc = rtems_semaphore_create (rtems_build_name ('B', 'D', 'C', 'b'), |
---|
1371 | 0, RTEMS_BDBUF_CACHE_WAITER_ATTRIBS, 0, |
---|
1372 | &bdbuf_cache.buffer_waiters.sema); |
---|
1373 | if (sc != RTEMS_SUCCESSFUL) |
---|
1374 | goto error; |
---|
1375 | |
---|
1376 | /* |
---|
1377 | * Compute the various number of elements in the cache. |
---|
1378 | */ |
---|
1379 | bdbuf_cache.buffer_min_count = |
---|
1380 | bdbuf_config.size / bdbuf_config.buffer_min; |
---|
1381 | bdbuf_cache.max_bds_per_group = |
---|
1382 | bdbuf_config.buffer_max / bdbuf_config.buffer_min; |
---|
1383 | bdbuf_cache.group_count = |
---|
1384 | bdbuf_cache.buffer_min_count / bdbuf_cache.max_bds_per_group; |
---|
1385 | |
---|
1386 | /* |
---|
1387 | * Allocate the memory for the buffer descriptors. |
---|
1388 | */ |
---|
1389 | bdbuf_cache.bds = calloc (sizeof (rtems_bdbuf_buffer), |
---|
1390 | bdbuf_cache.buffer_min_count); |
---|
1391 | if (!bdbuf_cache.bds) |
---|
1392 | goto error; |
---|
1393 | |
---|
1394 | /* |
---|
1395 | * Allocate the memory for the buffer descriptors. |
---|
1396 | */ |
---|
1397 | bdbuf_cache.groups = calloc (sizeof (rtems_bdbuf_group), |
---|
1398 | bdbuf_cache.group_count); |
---|
1399 | if (!bdbuf_cache.groups) |
---|
1400 | goto error; |
---|
1401 | |
---|
1402 | /* |
---|
1403 | * Allocate memory for buffer memory. The buffer memory will be cache |
---|
1404 | * aligned. It is possible to free the memory allocated by rtems_memalign() |
---|
1405 | * with free(). Return 0 if allocated. |
---|
1406 | * |
---|
1407 | * The memory allocate allows a |
---|
1408 | */ |
---|
1409 | if (rtems_memalign ((void **) &bdbuf_cache.buffers, |
---|
1410 | cache_aligment, |
---|
1411 | bdbuf_cache.buffer_min_count * bdbuf_config.buffer_min) != 0) |
---|
1412 | goto error; |
---|
1413 | |
---|
1414 | /* |
---|
1415 | * The cache is empty after opening so we need to add all the buffers to it |
---|
1416 | * and initialise the groups. |
---|
1417 | */ |
---|
1418 | for (b = 0, group = bdbuf_cache.groups, |
---|
1419 | bd = bdbuf_cache.bds, buffer = bdbuf_cache.buffers; |
---|
1420 | b < bdbuf_cache.buffer_min_count; |
---|
1421 | b++, bd++, buffer += bdbuf_config.buffer_min) |
---|
1422 | { |
---|
1423 | bd->dd = BDBUF_INVALID_DEV; |
---|
1424 | bd->group = group; |
---|
1425 | bd->buffer = buffer; |
---|
1426 | |
---|
1427 | rtems_chain_append_unprotected (&bdbuf_cache.lru, &bd->link); |
---|
1428 | |
---|
1429 | if ((b % bdbuf_cache.max_bds_per_group) == |
---|
1430 | (bdbuf_cache.max_bds_per_group - 1)) |
---|
1431 | group++; |
---|
1432 | } |
---|
1433 | |
---|
1434 | for (b = 0, |
---|
1435 | group = bdbuf_cache.groups, |
---|
1436 | bd = bdbuf_cache.bds; |
---|
1437 | b < bdbuf_cache.group_count; |
---|
1438 | b++, |
---|
1439 | group++, |
---|
1440 | bd += bdbuf_cache.max_bds_per_group) |
---|
1441 | { |
---|
1442 | group->bds_per_group = bdbuf_cache.max_bds_per_group; |
---|
1443 | group->bdbuf = bd; |
---|
1444 | } |
---|
1445 | |
---|
1446 | /* |
---|
1447 | * Create and start swapout task. This task will create and manage the worker |
---|
1448 | * threads. |
---|
1449 | */ |
---|
1450 | bdbuf_cache.swapout_enabled = true; |
---|
1451 | |
---|
1452 | sc = rtems_task_create (rtems_build_name('B', 'S', 'W', 'P'), |
---|
1453 | bdbuf_config.swapout_priority ? |
---|
1454 | bdbuf_config.swapout_priority : |
---|
1455 | RTEMS_BDBUF_SWAPOUT_TASK_PRIORITY_DEFAULT, |
---|
1456 | SWAPOUT_TASK_STACK_SIZE, |
---|
1457 | RTEMS_PREEMPT | RTEMS_NO_TIMESLICE | RTEMS_NO_ASR, |
---|
1458 | RTEMS_LOCAL | RTEMS_NO_FLOATING_POINT, |
---|
1459 | &bdbuf_cache.swapout); |
---|
1460 | if (sc != RTEMS_SUCCESSFUL) |
---|
1461 | goto error; |
---|
1462 | |
---|
1463 | sc = rtems_task_start (bdbuf_cache.swapout, |
---|
1464 | rtems_bdbuf_swapout_task, |
---|
1465 | (rtems_task_argument) &bdbuf_cache); |
---|
1466 | if (sc != RTEMS_SUCCESSFUL) |
---|
1467 | goto error; |
---|
1468 | |
---|
1469 | rtems_bdbuf_unlock_cache (); |
---|
1470 | |
---|
1471 | return RTEMS_SUCCESSFUL; |
---|
1472 | |
---|
1473 | error: |
---|
1474 | |
---|
1475 | if (bdbuf_cache.swapout != 0) |
---|
1476 | rtems_task_delete (bdbuf_cache.swapout); |
---|
1477 | |
---|
1478 | free (bdbuf_cache.buffers); |
---|
1479 | free (bdbuf_cache.groups); |
---|
1480 | free (bdbuf_cache.bds); |
---|
1481 | |
---|
1482 | rtems_semaphore_delete (bdbuf_cache.buffer_waiters.sema); |
---|
1483 | rtems_semaphore_delete (bdbuf_cache.access_waiters.sema); |
---|
1484 | rtems_semaphore_delete (bdbuf_cache.transfer_waiters.sema); |
---|
1485 | rtems_semaphore_delete (bdbuf_cache.sync_lock); |
---|
1486 | |
---|
1487 | if (bdbuf_cache.lock != 0) |
---|
1488 | { |
---|
1489 | rtems_bdbuf_unlock_cache (); |
---|
1490 | rtems_semaphore_delete (bdbuf_cache.lock); |
---|
1491 | } |
---|
1492 | |
---|
1493 | bdbuf_cache.initialised = false; |
---|
1494 | |
---|
1495 | return RTEMS_UNSATISFIED; |
---|
1496 | } |
---|
1497 | |
---|
1498 | static void |
---|
1499 | rtems_bdbuf_wait_for_event (rtems_event_set event) |
---|
1500 | { |
---|
1501 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
1502 | rtems_event_set out = 0; |
---|
1503 | |
---|
1504 | sc = rtems_event_receive (event, |
---|
1505 | RTEMS_EVENT_ALL | RTEMS_WAIT, |
---|
1506 | RTEMS_NO_TIMEOUT, |
---|
1507 | &out); |
---|
1508 | |
---|
1509 | if (sc != RTEMS_SUCCESSFUL || out != event) |
---|
1510 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_WAIT_EVNT); |
---|
1511 | } |
---|
1512 | |
---|
1513 | static void |
---|
1514 | rtems_bdbuf_wait_for_access (rtems_bdbuf_buffer *bd) |
---|
1515 | { |
---|
1516 | while (true) |
---|
1517 | { |
---|
1518 | switch (bd->state) |
---|
1519 | { |
---|
1520 | case RTEMS_BDBUF_STATE_MODIFIED: |
---|
1521 | rtems_bdbuf_group_release (bd); |
---|
1522 | /* Fall through */ |
---|
1523 | case RTEMS_BDBUF_STATE_CACHED: |
---|
1524 | rtems_chain_extract_unprotected (&bd->link); |
---|
1525 | /* Fall through */ |
---|
1526 | case RTEMS_BDBUF_STATE_EMPTY: |
---|
1527 | return; |
---|
1528 | case RTEMS_BDBUF_STATE_ACCESS_CACHED: |
---|
1529 | case RTEMS_BDBUF_STATE_ACCESS_EMPTY: |
---|
1530 | case RTEMS_BDBUF_STATE_ACCESS_MODIFIED: |
---|
1531 | case RTEMS_BDBUF_STATE_ACCESS_PURGED: |
---|
1532 | rtems_bdbuf_wait (bd, &bdbuf_cache.access_waiters); |
---|
1533 | break; |
---|
1534 | case RTEMS_BDBUF_STATE_SYNC: |
---|
1535 | case RTEMS_BDBUF_STATE_TRANSFER: |
---|
1536 | case RTEMS_BDBUF_STATE_TRANSFER_PURGED: |
---|
1537 | rtems_bdbuf_wait (bd, &bdbuf_cache.transfer_waiters); |
---|
1538 | break; |
---|
1539 | default: |
---|
1540 | rtems_bdbuf_fatal (bd->state, RTEMS_BLKDEV_FATAL_BDBUF_STATE_7); |
---|
1541 | } |
---|
1542 | } |
---|
1543 | } |
---|
1544 | |
---|
1545 | static void |
---|
1546 | rtems_bdbuf_request_sync_for_modified_buffer (rtems_bdbuf_buffer *bd) |
---|
1547 | { |
---|
1548 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_SYNC); |
---|
1549 | rtems_chain_extract_unprotected (&bd->link); |
---|
1550 | rtems_chain_append_unprotected (&bdbuf_cache.sync, &bd->link); |
---|
1551 | rtems_bdbuf_wake_swapper (); |
---|
1552 | } |
---|
1553 | |
---|
1554 | /** |
---|
1555 | * @brief Waits until the buffer is ready for recycling. |
---|
1556 | * |
---|
1557 | * @retval @c true Buffer is valid and may be recycled. |
---|
1558 | * @retval @c false Buffer is invalid and has to searched again. |
---|
1559 | */ |
---|
1560 | static bool |
---|
1561 | rtems_bdbuf_wait_for_recycle (rtems_bdbuf_buffer *bd) |
---|
1562 | { |
---|
1563 | while (true) |
---|
1564 | { |
---|
1565 | switch (bd->state) |
---|
1566 | { |
---|
1567 | case RTEMS_BDBUF_STATE_FREE: |
---|
1568 | return true; |
---|
1569 | case RTEMS_BDBUF_STATE_MODIFIED: |
---|
1570 | rtems_bdbuf_request_sync_for_modified_buffer (bd); |
---|
1571 | break; |
---|
1572 | case RTEMS_BDBUF_STATE_CACHED: |
---|
1573 | case RTEMS_BDBUF_STATE_EMPTY: |
---|
1574 | if (bd->waiters == 0) |
---|
1575 | return true; |
---|
1576 | else |
---|
1577 | { |
---|
1578 | /* |
---|
1579 | * It is essential that we wait here without a special wait count and |
---|
1580 | * without the group in use. Otherwise we could trigger a wait ping |
---|
1581 | * pong with another recycle waiter. The state of the buffer is |
---|
1582 | * arbitrary afterwards. |
---|
1583 | */ |
---|
1584 | rtems_bdbuf_anonymous_wait (&bdbuf_cache.buffer_waiters); |
---|
1585 | return false; |
---|
1586 | } |
---|
1587 | case RTEMS_BDBUF_STATE_ACCESS_CACHED: |
---|
1588 | case RTEMS_BDBUF_STATE_ACCESS_EMPTY: |
---|
1589 | case RTEMS_BDBUF_STATE_ACCESS_MODIFIED: |
---|
1590 | case RTEMS_BDBUF_STATE_ACCESS_PURGED: |
---|
1591 | rtems_bdbuf_wait (bd, &bdbuf_cache.access_waiters); |
---|
1592 | break; |
---|
1593 | case RTEMS_BDBUF_STATE_SYNC: |
---|
1594 | case RTEMS_BDBUF_STATE_TRANSFER: |
---|
1595 | case RTEMS_BDBUF_STATE_TRANSFER_PURGED: |
---|
1596 | rtems_bdbuf_wait (bd, &bdbuf_cache.transfer_waiters); |
---|
1597 | break; |
---|
1598 | default: |
---|
1599 | rtems_bdbuf_fatal (bd->state, RTEMS_BLKDEV_FATAL_BDBUF_STATE_8); |
---|
1600 | } |
---|
1601 | } |
---|
1602 | } |
---|
1603 | |
---|
1604 | static void |
---|
1605 | rtems_bdbuf_wait_for_sync_done (rtems_bdbuf_buffer *bd) |
---|
1606 | { |
---|
1607 | while (true) |
---|
1608 | { |
---|
1609 | switch (bd->state) |
---|
1610 | { |
---|
1611 | case RTEMS_BDBUF_STATE_CACHED: |
---|
1612 | case RTEMS_BDBUF_STATE_EMPTY: |
---|
1613 | case RTEMS_BDBUF_STATE_MODIFIED: |
---|
1614 | case RTEMS_BDBUF_STATE_ACCESS_CACHED: |
---|
1615 | case RTEMS_BDBUF_STATE_ACCESS_EMPTY: |
---|
1616 | case RTEMS_BDBUF_STATE_ACCESS_MODIFIED: |
---|
1617 | case RTEMS_BDBUF_STATE_ACCESS_PURGED: |
---|
1618 | return; |
---|
1619 | case RTEMS_BDBUF_STATE_SYNC: |
---|
1620 | case RTEMS_BDBUF_STATE_TRANSFER: |
---|
1621 | case RTEMS_BDBUF_STATE_TRANSFER_PURGED: |
---|
1622 | rtems_bdbuf_wait (bd, &bdbuf_cache.transfer_waiters); |
---|
1623 | break; |
---|
1624 | default: |
---|
1625 | rtems_bdbuf_fatal (bd->state, RTEMS_BLKDEV_FATAL_BDBUF_STATE_9); |
---|
1626 | } |
---|
1627 | } |
---|
1628 | } |
---|
1629 | |
---|
1630 | static void |
---|
1631 | rtems_bdbuf_wait_for_buffer (void) |
---|
1632 | { |
---|
1633 | if (!rtems_chain_is_empty (&bdbuf_cache.modified)) |
---|
1634 | rtems_bdbuf_wake_swapper (); |
---|
1635 | |
---|
1636 | rtems_bdbuf_anonymous_wait (&bdbuf_cache.buffer_waiters); |
---|
1637 | } |
---|
1638 | |
---|
1639 | static void |
---|
1640 | rtems_bdbuf_sync_after_access (rtems_bdbuf_buffer *bd) |
---|
1641 | { |
---|
1642 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_SYNC); |
---|
1643 | |
---|
1644 | rtems_chain_append_unprotected (&bdbuf_cache.sync, &bd->link); |
---|
1645 | |
---|
1646 | if (bd->waiters) |
---|
1647 | rtems_bdbuf_wake (&bdbuf_cache.access_waiters); |
---|
1648 | |
---|
1649 | rtems_bdbuf_wake_swapper (); |
---|
1650 | rtems_bdbuf_wait_for_sync_done (bd); |
---|
1651 | |
---|
1652 | /* |
---|
1653 | * We may have created a cached or empty buffer which may be recycled. |
---|
1654 | */ |
---|
1655 | if (bd->waiters == 0 |
---|
1656 | && (bd->state == RTEMS_BDBUF_STATE_CACHED |
---|
1657 | || bd->state == RTEMS_BDBUF_STATE_EMPTY)) |
---|
1658 | { |
---|
1659 | if (bd->state == RTEMS_BDBUF_STATE_EMPTY) |
---|
1660 | { |
---|
1661 | rtems_bdbuf_remove_from_tree (bd); |
---|
1662 | rtems_bdbuf_make_free_and_add_to_lru_list (bd); |
---|
1663 | } |
---|
1664 | rtems_bdbuf_wake (&bdbuf_cache.buffer_waiters); |
---|
1665 | } |
---|
1666 | } |
---|
1667 | |
---|
1668 | static rtems_bdbuf_buffer * |
---|
1669 | rtems_bdbuf_get_buffer_for_read_ahead (const rtems_disk_device *dd, |
---|
1670 | rtems_blkdev_bnum block, |
---|
1671 | size_t bds_per_group) |
---|
1672 | { |
---|
1673 | rtems_bdbuf_buffer *bd = NULL; |
---|
1674 | |
---|
1675 | bd = rtems_bdbuf_avl_search (&bdbuf_cache.tree, dd, block); |
---|
1676 | |
---|
1677 | if (bd == NULL) |
---|
1678 | { |
---|
1679 | bd = rtems_bdbuf_get_buffer_from_lru_list (dd, block, bds_per_group); |
---|
1680 | |
---|
1681 | if (bd != NULL) |
---|
1682 | rtems_bdbuf_group_obtain (bd); |
---|
1683 | } |
---|
1684 | else |
---|
1685 | /* |
---|
1686 | * The buffer is in the cache. So it is already available or in use, and |
---|
1687 | * thus no need for a read ahead. |
---|
1688 | */ |
---|
1689 | bd = NULL; |
---|
1690 | |
---|
1691 | return bd; |
---|
1692 | } |
---|
1693 | |
---|
1694 | static rtems_bdbuf_buffer * |
---|
1695 | rtems_bdbuf_get_buffer_for_access (const rtems_disk_device *dd, |
---|
1696 | rtems_blkdev_bnum block, |
---|
1697 | size_t bds_per_group) |
---|
1698 | { |
---|
1699 | rtems_bdbuf_buffer *bd = NULL; |
---|
1700 | |
---|
1701 | do |
---|
1702 | { |
---|
1703 | bd = rtems_bdbuf_avl_search (&bdbuf_cache.tree, dd, block); |
---|
1704 | |
---|
1705 | if (bd != NULL) |
---|
1706 | { |
---|
1707 | if (bd->group->bds_per_group != bds_per_group) |
---|
1708 | { |
---|
1709 | if (rtems_bdbuf_wait_for_recycle (bd)) |
---|
1710 | { |
---|
1711 | rtems_bdbuf_remove_from_tree_and_lru_list (bd); |
---|
1712 | rtems_bdbuf_make_free_and_add_to_lru_list (bd); |
---|
1713 | rtems_bdbuf_wake (&bdbuf_cache.buffer_waiters); |
---|
1714 | } |
---|
1715 | bd = NULL; |
---|
1716 | } |
---|
1717 | } |
---|
1718 | else |
---|
1719 | { |
---|
1720 | bd = rtems_bdbuf_get_buffer_from_lru_list (dd, block, bds_per_group); |
---|
1721 | |
---|
1722 | if (bd == NULL) |
---|
1723 | rtems_bdbuf_wait_for_buffer (); |
---|
1724 | } |
---|
1725 | } |
---|
1726 | while (bd == NULL); |
---|
1727 | |
---|
1728 | rtems_bdbuf_wait_for_access (bd); |
---|
1729 | rtems_bdbuf_group_obtain (bd); |
---|
1730 | |
---|
1731 | return bd; |
---|
1732 | } |
---|
1733 | |
---|
1734 | static rtems_status_code |
---|
1735 | rtems_bdbuf_get_media_block (const rtems_disk_device *dd, |
---|
1736 | rtems_blkdev_bnum block, |
---|
1737 | rtems_blkdev_bnum *media_block_ptr) |
---|
1738 | { |
---|
1739 | /* |
---|
1740 | * Compute the media block number. Drivers work with media block number not |
---|
1741 | * the block number a BD may have as this depends on the block size set by |
---|
1742 | * the user. |
---|
1743 | */ |
---|
1744 | rtems_blkdev_bnum mb = rtems_bdbuf_media_block (dd, block); |
---|
1745 | if (mb >= dd->size) |
---|
1746 | { |
---|
1747 | return RTEMS_INVALID_NUMBER; |
---|
1748 | } |
---|
1749 | |
---|
1750 | *media_block_ptr = mb + dd->start; |
---|
1751 | |
---|
1752 | return RTEMS_SUCCESSFUL; |
---|
1753 | } |
---|
1754 | |
---|
1755 | rtems_status_code |
---|
1756 | rtems_bdbuf_get (const rtems_disk_device *dd, |
---|
1757 | rtems_blkdev_bnum block, |
---|
1758 | rtems_bdbuf_buffer **bd_ptr) |
---|
1759 | { |
---|
1760 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
1761 | rtems_bdbuf_buffer *bd = NULL; |
---|
1762 | rtems_blkdev_bnum media_block = 0; |
---|
1763 | |
---|
1764 | sc = rtems_bdbuf_get_media_block (dd, block, &media_block); |
---|
1765 | if (sc != RTEMS_SUCCESSFUL) |
---|
1766 | return sc; |
---|
1767 | |
---|
1768 | rtems_bdbuf_lock_cache (); |
---|
1769 | |
---|
1770 | /* |
---|
1771 | * Print the block index relative to the physical disk. |
---|
1772 | */ |
---|
1773 | if (rtems_bdbuf_tracer) |
---|
1774 | printf ("bdbuf:get: %" PRIu32 " (%" PRIu32 ") (dev = %08x)\n", |
---|
1775 | media_block, block, (unsigned) dd->dev); |
---|
1776 | |
---|
1777 | bd = rtems_bdbuf_get_buffer_for_access (dd, media_block, dd->bds_per_group); |
---|
1778 | |
---|
1779 | switch (bd->state) |
---|
1780 | { |
---|
1781 | case RTEMS_BDBUF_STATE_CACHED: |
---|
1782 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_ACCESS_CACHED); |
---|
1783 | break; |
---|
1784 | case RTEMS_BDBUF_STATE_EMPTY: |
---|
1785 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_ACCESS_EMPTY); |
---|
1786 | break; |
---|
1787 | case RTEMS_BDBUF_STATE_MODIFIED: |
---|
1788 | /* |
---|
1789 | * To get a modified buffer could be considered a bug in the caller |
---|
1790 | * because you should not be getting an already modified buffer but user |
---|
1791 | * may have modified a byte in a block then decided to seek the start and |
---|
1792 | * write the whole block and the file system will have no record of this |
---|
1793 | * so just gets the block to fill. |
---|
1794 | */ |
---|
1795 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_ACCESS_MODIFIED); |
---|
1796 | break; |
---|
1797 | default: |
---|
1798 | rtems_bdbuf_fatal (bd->state, RTEMS_BLKDEV_FATAL_BDBUF_STATE_2); |
---|
1799 | break; |
---|
1800 | } |
---|
1801 | |
---|
1802 | if (rtems_bdbuf_tracer) |
---|
1803 | { |
---|
1804 | rtems_bdbuf_show_users ("get", bd); |
---|
1805 | rtems_bdbuf_show_usage (); |
---|
1806 | } |
---|
1807 | |
---|
1808 | rtems_bdbuf_unlock_cache (); |
---|
1809 | |
---|
1810 | *bd_ptr = bd; |
---|
1811 | |
---|
1812 | return RTEMS_SUCCESSFUL; |
---|
1813 | } |
---|
1814 | |
---|
1815 | /** |
---|
1816 | * Call back handler called by the low level driver when the transfer has |
---|
1817 | * completed. This function may be invoked from interrupt handler. |
---|
1818 | * |
---|
1819 | * @param arg Arbitrary argument specified in block device request |
---|
1820 | * structure (in this case - pointer to the appropriate |
---|
1821 | * block device request structure). |
---|
1822 | * @param status I/O completion status |
---|
1823 | */ |
---|
1824 | static void |
---|
1825 | rtems_bdbuf_transfer_done (void* arg, rtems_status_code status) |
---|
1826 | { |
---|
1827 | rtems_blkdev_request* req = (rtems_blkdev_request*) arg; |
---|
1828 | |
---|
1829 | req->status = status; |
---|
1830 | |
---|
1831 | rtems_event_send (req->io_task, RTEMS_BDBUF_TRANSFER_SYNC); |
---|
1832 | } |
---|
1833 | |
---|
1834 | static void |
---|
1835 | rtems_bdbuf_create_read_request (const rtems_disk_device *dd, |
---|
1836 | rtems_blkdev_bnum media_block, |
---|
1837 | size_t bds_per_group, |
---|
1838 | rtems_blkdev_request *req, |
---|
1839 | rtems_bdbuf_buffer **bd_ptr) |
---|
1840 | { |
---|
1841 | rtems_bdbuf_buffer *bd = NULL; |
---|
1842 | rtems_blkdev_bnum media_block_end = dd->start + dd->size; |
---|
1843 | rtems_blkdev_bnum media_block_count = dd->block_to_media_block_shift >= 0 ? |
---|
1844 | dd->block_size >> dd->block_to_media_block_shift |
---|
1845 | : dd->block_size / dd->media_block_size; |
---|
1846 | uint32_t block_size = dd->block_size; |
---|
1847 | uint32_t transfer_index = 1; |
---|
1848 | uint32_t transfer_count = bdbuf_config.max_read_ahead_blocks + 1; |
---|
1849 | |
---|
1850 | if (media_block_end - media_block < transfer_count) |
---|
1851 | transfer_count = media_block_end - media_block; |
---|
1852 | |
---|
1853 | req->req = RTEMS_BLKDEV_REQ_READ; |
---|
1854 | req->req_done = rtems_bdbuf_transfer_done; |
---|
1855 | req->done_arg = req; |
---|
1856 | req->io_task = rtems_task_self (); |
---|
1857 | req->status = RTEMS_RESOURCE_IN_USE; |
---|
1858 | req->bufnum = 0; |
---|
1859 | |
---|
1860 | bd = rtems_bdbuf_get_buffer_for_access (dd, media_block, bds_per_group); |
---|
1861 | |
---|
1862 | *bd_ptr = bd; |
---|
1863 | |
---|
1864 | req->bufs [0].user = bd; |
---|
1865 | req->bufs [0].block = media_block; |
---|
1866 | req->bufs [0].length = block_size; |
---|
1867 | req->bufs [0].buffer = bd->buffer; |
---|
1868 | |
---|
1869 | if (rtems_bdbuf_tracer) |
---|
1870 | rtems_bdbuf_show_users ("read", bd); |
---|
1871 | |
---|
1872 | switch (bd->state) |
---|
1873 | { |
---|
1874 | case RTEMS_BDBUF_STATE_CACHED: |
---|
1875 | case RTEMS_BDBUF_STATE_MODIFIED: |
---|
1876 | return; |
---|
1877 | case RTEMS_BDBUF_STATE_EMPTY: |
---|
1878 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_TRANSFER); |
---|
1879 | break; |
---|
1880 | default: |
---|
1881 | rtems_bdbuf_fatal (bd->state, RTEMS_BLKDEV_FATAL_BDBUF_STATE_1); |
---|
1882 | break; |
---|
1883 | } |
---|
1884 | |
---|
1885 | while (transfer_index < transfer_count) |
---|
1886 | { |
---|
1887 | media_block += media_block_count; |
---|
1888 | |
---|
1889 | bd = rtems_bdbuf_get_buffer_for_read_ahead (dd, media_block, |
---|
1890 | bds_per_group); |
---|
1891 | |
---|
1892 | if (bd == NULL) |
---|
1893 | break; |
---|
1894 | |
---|
1895 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_TRANSFER); |
---|
1896 | |
---|
1897 | req->bufs [transfer_index].user = bd; |
---|
1898 | req->bufs [transfer_index].block = media_block; |
---|
1899 | req->bufs [transfer_index].length = block_size; |
---|
1900 | req->bufs [transfer_index].buffer = bd->buffer; |
---|
1901 | |
---|
1902 | if (rtems_bdbuf_tracer) |
---|
1903 | rtems_bdbuf_show_users ("read-ahead", bd); |
---|
1904 | |
---|
1905 | ++transfer_index; |
---|
1906 | } |
---|
1907 | |
---|
1908 | req->bufnum = transfer_index; |
---|
1909 | } |
---|
1910 | |
---|
1911 | static rtems_status_code |
---|
1912 | rtems_bdbuf_execute_transfer_request (const rtems_disk_device *dd, |
---|
1913 | rtems_blkdev_request *req, |
---|
1914 | bool cache_locked) |
---|
1915 | { |
---|
1916 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
1917 | int result = 0; |
---|
1918 | uint32_t transfer_index = 0; |
---|
1919 | bool wake_transfer_waiters = false; |
---|
1920 | bool wake_buffer_waiters = false; |
---|
1921 | |
---|
1922 | if (cache_locked) |
---|
1923 | rtems_bdbuf_unlock_cache (); |
---|
1924 | |
---|
1925 | result = dd->ioctl (dd->phys_dev, RTEMS_BLKIO_REQUEST, req); |
---|
1926 | |
---|
1927 | if (result == 0) |
---|
1928 | { |
---|
1929 | rtems_bdbuf_wait_for_event (RTEMS_BDBUF_TRANSFER_SYNC); |
---|
1930 | sc = req->status; |
---|
1931 | } |
---|
1932 | else |
---|
1933 | sc = RTEMS_IO_ERROR; |
---|
1934 | |
---|
1935 | rtems_bdbuf_lock_cache (); |
---|
1936 | |
---|
1937 | for (transfer_index = 0; transfer_index < req->bufnum; ++transfer_index) |
---|
1938 | { |
---|
1939 | rtems_bdbuf_buffer *bd = req->bufs [transfer_index].user; |
---|
1940 | bool waiters = bd->waiters; |
---|
1941 | |
---|
1942 | if (waiters) |
---|
1943 | wake_transfer_waiters = true; |
---|
1944 | else |
---|
1945 | wake_buffer_waiters = true; |
---|
1946 | |
---|
1947 | rtems_bdbuf_group_release (bd); |
---|
1948 | |
---|
1949 | if (sc == RTEMS_SUCCESSFUL && bd->state == RTEMS_BDBUF_STATE_TRANSFER) |
---|
1950 | rtems_bdbuf_make_cached_and_add_to_lru_list (bd); |
---|
1951 | else |
---|
1952 | rtems_bdbuf_discard_buffer (bd); |
---|
1953 | |
---|
1954 | if (rtems_bdbuf_tracer) |
---|
1955 | rtems_bdbuf_show_users ("transfer", bd); |
---|
1956 | } |
---|
1957 | |
---|
1958 | if (wake_transfer_waiters) |
---|
1959 | rtems_bdbuf_wake (&bdbuf_cache.transfer_waiters); |
---|
1960 | |
---|
1961 | if (wake_buffer_waiters) |
---|
1962 | rtems_bdbuf_wake (&bdbuf_cache.buffer_waiters); |
---|
1963 | |
---|
1964 | if (!cache_locked) |
---|
1965 | rtems_bdbuf_unlock_cache (); |
---|
1966 | |
---|
1967 | if (sc == RTEMS_SUCCESSFUL || sc == RTEMS_UNSATISFIED) |
---|
1968 | return sc; |
---|
1969 | else |
---|
1970 | return RTEMS_IO_ERROR; |
---|
1971 | } |
---|
1972 | |
---|
1973 | rtems_status_code |
---|
1974 | rtems_bdbuf_read (const rtems_disk_device *dd, |
---|
1975 | rtems_blkdev_bnum block, |
---|
1976 | rtems_bdbuf_buffer **bd_ptr) |
---|
1977 | { |
---|
1978 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
1979 | rtems_blkdev_request *req = NULL; |
---|
1980 | rtems_bdbuf_buffer *bd = NULL; |
---|
1981 | rtems_blkdev_bnum media_block = 0; |
---|
1982 | |
---|
1983 | sc = rtems_bdbuf_get_media_block (dd, block, &media_block); |
---|
1984 | if (sc != RTEMS_SUCCESSFUL) |
---|
1985 | return sc; |
---|
1986 | |
---|
1987 | /* |
---|
1988 | * TODO: This type of request structure is wrong and should be removed. |
---|
1989 | */ |
---|
1990 | #define bdbuf_alloc(size) __builtin_alloca (size) |
---|
1991 | |
---|
1992 | req = bdbuf_alloc (sizeof (rtems_blkdev_request) + |
---|
1993 | sizeof (rtems_blkdev_sg_buffer) * |
---|
1994 | (bdbuf_config.max_read_ahead_blocks + 1)); |
---|
1995 | |
---|
1996 | if (rtems_bdbuf_tracer) |
---|
1997 | printf ("bdbuf:read: %" PRIu32 " (%" PRIu32 ") (dev = %08x)\n", |
---|
1998 | media_block + dd->start, block, (unsigned) dd->dev); |
---|
1999 | |
---|
2000 | rtems_bdbuf_lock_cache (); |
---|
2001 | rtems_bdbuf_create_read_request (dd, media_block, dd->bds_per_group, req, &bd); |
---|
2002 | |
---|
2003 | if (req->bufnum > 0) |
---|
2004 | { |
---|
2005 | sc = rtems_bdbuf_execute_transfer_request (dd, req, true); |
---|
2006 | if (sc == RTEMS_SUCCESSFUL) |
---|
2007 | { |
---|
2008 | rtems_chain_extract_unprotected (&bd->link); |
---|
2009 | rtems_bdbuf_group_obtain (bd); |
---|
2010 | } |
---|
2011 | } |
---|
2012 | |
---|
2013 | if (sc == RTEMS_SUCCESSFUL) |
---|
2014 | { |
---|
2015 | switch (bd->state) |
---|
2016 | { |
---|
2017 | case RTEMS_BDBUF_STATE_CACHED: |
---|
2018 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_ACCESS_CACHED); |
---|
2019 | break; |
---|
2020 | case RTEMS_BDBUF_STATE_MODIFIED: |
---|
2021 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_ACCESS_MODIFIED); |
---|
2022 | break; |
---|
2023 | default: |
---|
2024 | rtems_bdbuf_fatal (bd->state, RTEMS_BLKDEV_FATAL_BDBUF_STATE_4); |
---|
2025 | break; |
---|
2026 | } |
---|
2027 | |
---|
2028 | if (rtems_bdbuf_tracer) |
---|
2029 | { |
---|
2030 | rtems_bdbuf_show_users ("read", bd); |
---|
2031 | rtems_bdbuf_show_usage (); |
---|
2032 | } |
---|
2033 | |
---|
2034 | *bd_ptr = bd; |
---|
2035 | } |
---|
2036 | else |
---|
2037 | *bd_ptr = NULL; |
---|
2038 | |
---|
2039 | rtems_bdbuf_unlock_cache (); |
---|
2040 | |
---|
2041 | return sc; |
---|
2042 | } |
---|
2043 | |
---|
2044 | static rtems_status_code |
---|
2045 | rtems_bdbuf_check_bd_and_lock_cache (rtems_bdbuf_buffer *bd, const char *kind) |
---|
2046 | { |
---|
2047 | if (bd == NULL) |
---|
2048 | return RTEMS_INVALID_ADDRESS; |
---|
2049 | if (rtems_bdbuf_tracer) |
---|
2050 | { |
---|
2051 | printf ("bdbuf:%s: %" PRIu32 "\n", kind, bd->block); |
---|
2052 | rtems_bdbuf_show_users (kind, bd); |
---|
2053 | } |
---|
2054 | rtems_bdbuf_lock_cache(); |
---|
2055 | |
---|
2056 | return RTEMS_SUCCESSFUL; |
---|
2057 | } |
---|
2058 | |
---|
2059 | rtems_status_code |
---|
2060 | rtems_bdbuf_release (rtems_bdbuf_buffer *bd) |
---|
2061 | { |
---|
2062 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
2063 | |
---|
2064 | sc = rtems_bdbuf_check_bd_and_lock_cache (bd, "release"); |
---|
2065 | if (sc != RTEMS_SUCCESSFUL) |
---|
2066 | return sc; |
---|
2067 | |
---|
2068 | switch (bd->state) |
---|
2069 | { |
---|
2070 | case RTEMS_BDBUF_STATE_ACCESS_CACHED: |
---|
2071 | rtems_bdbuf_add_to_lru_list_after_access (bd); |
---|
2072 | break; |
---|
2073 | case RTEMS_BDBUF_STATE_ACCESS_EMPTY: |
---|
2074 | case RTEMS_BDBUF_STATE_ACCESS_PURGED: |
---|
2075 | rtems_bdbuf_discard_buffer_after_access (bd); |
---|
2076 | break; |
---|
2077 | case RTEMS_BDBUF_STATE_ACCESS_MODIFIED: |
---|
2078 | rtems_bdbuf_add_to_modified_list_after_access (bd); |
---|
2079 | break; |
---|
2080 | default: |
---|
2081 | rtems_bdbuf_fatal (bd->state, RTEMS_BLKDEV_FATAL_BDBUF_STATE_0); |
---|
2082 | break; |
---|
2083 | } |
---|
2084 | |
---|
2085 | if (rtems_bdbuf_tracer) |
---|
2086 | rtems_bdbuf_show_usage (); |
---|
2087 | |
---|
2088 | rtems_bdbuf_unlock_cache (); |
---|
2089 | |
---|
2090 | return RTEMS_SUCCESSFUL; |
---|
2091 | } |
---|
2092 | |
---|
2093 | rtems_status_code |
---|
2094 | rtems_bdbuf_release_modified (rtems_bdbuf_buffer *bd) |
---|
2095 | { |
---|
2096 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
2097 | |
---|
2098 | sc = rtems_bdbuf_check_bd_and_lock_cache (bd, "release modified"); |
---|
2099 | if (sc != RTEMS_SUCCESSFUL) |
---|
2100 | return sc; |
---|
2101 | |
---|
2102 | switch (bd->state) |
---|
2103 | { |
---|
2104 | case RTEMS_BDBUF_STATE_ACCESS_CACHED: |
---|
2105 | case RTEMS_BDBUF_STATE_ACCESS_EMPTY: |
---|
2106 | case RTEMS_BDBUF_STATE_ACCESS_MODIFIED: |
---|
2107 | rtems_bdbuf_add_to_modified_list_after_access (bd); |
---|
2108 | break; |
---|
2109 | case RTEMS_BDBUF_STATE_ACCESS_PURGED: |
---|
2110 | rtems_bdbuf_discard_buffer_after_access (bd); |
---|
2111 | break; |
---|
2112 | default: |
---|
2113 | rtems_bdbuf_fatal (bd->state, RTEMS_BLKDEV_FATAL_BDBUF_STATE_6); |
---|
2114 | break; |
---|
2115 | } |
---|
2116 | |
---|
2117 | if (rtems_bdbuf_tracer) |
---|
2118 | rtems_bdbuf_show_usage (); |
---|
2119 | |
---|
2120 | rtems_bdbuf_unlock_cache (); |
---|
2121 | |
---|
2122 | return RTEMS_SUCCESSFUL; |
---|
2123 | } |
---|
2124 | |
---|
2125 | rtems_status_code |
---|
2126 | rtems_bdbuf_sync (rtems_bdbuf_buffer *bd) |
---|
2127 | { |
---|
2128 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
2129 | |
---|
2130 | sc = rtems_bdbuf_check_bd_and_lock_cache (bd, "sync"); |
---|
2131 | if (sc != RTEMS_SUCCESSFUL) |
---|
2132 | return sc; |
---|
2133 | |
---|
2134 | switch (bd->state) |
---|
2135 | { |
---|
2136 | case RTEMS_BDBUF_STATE_ACCESS_CACHED: |
---|
2137 | case RTEMS_BDBUF_STATE_ACCESS_EMPTY: |
---|
2138 | case RTEMS_BDBUF_STATE_ACCESS_MODIFIED: |
---|
2139 | rtems_bdbuf_sync_after_access (bd); |
---|
2140 | break; |
---|
2141 | case RTEMS_BDBUF_STATE_ACCESS_PURGED: |
---|
2142 | rtems_bdbuf_discard_buffer_after_access (bd); |
---|
2143 | break; |
---|
2144 | default: |
---|
2145 | rtems_bdbuf_fatal (bd->state, RTEMS_BLKDEV_FATAL_BDBUF_STATE_5); |
---|
2146 | break; |
---|
2147 | } |
---|
2148 | |
---|
2149 | if (rtems_bdbuf_tracer) |
---|
2150 | rtems_bdbuf_show_usage (); |
---|
2151 | |
---|
2152 | rtems_bdbuf_unlock_cache (); |
---|
2153 | |
---|
2154 | return RTEMS_SUCCESSFUL; |
---|
2155 | } |
---|
2156 | |
---|
2157 | rtems_status_code |
---|
2158 | rtems_bdbuf_syncdev (const rtems_disk_device *dd) |
---|
2159 | { |
---|
2160 | if (rtems_bdbuf_tracer) |
---|
2161 | printf ("bdbuf:syncdev: %08x\n", (unsigned) dd->dev); |
---|
2162 | |
---|
2163 | /* |
---|
2164 | * Take the sync lock before locking the cache. Once we have the sync lock we |
---|
2165 | * can lock the cache. If another thread has the sync lock it will cause this |
---|
2166 | * thread to block until it owns the sync lock then it can own the cache. The |
---|
2167 | * sync lock can only be obtained with the cache unlocked. |
---|
2168 | */ |
---|
2169 | rtems_bdbuf_lock_sync (); |
---|
2170 | rtems_bdbuf_lock_cache (); |
---|
2171 | |
---|
2172 | /* |
---|
2173 | * Set the cache to have a sync active for a specific device and let the swap |
---|
2174 | * out task know the id of the requester to wake when done. |
---|
2175 | * |
---|
2176 | * The swap out task will negate the sync active flag when no more buffers |
---|
2177 | * for the device are held on the "modified for sync" queues. |
---|
2178 | */ |
---|
2179 | bdbuf_cache.sync_active = true; |
---|
2180 | bdbuf_cache.sync_requester = rtems_task_self (); |
---|
2181 | bdbuf_cache.sync_device = dd; |
---|
2182 | |
---|
2183 | rtems_bdbuf_wake_swapper (); |
---|
2184 | rtems_bdbuf_unlock_cache (); |
---|
2185 | rtems_bdbuf_wait_for_event (RTEMS_BDBUF_TRANSFER_SYNC); |
---|
2186 | rtems_bdbuf_unlock_sync (); |
---|
2187 | |
---|
2188 | return RTEMS_SUCCESSFUL; |
---|
2189 | } |
---|
2190 | |
---|
2191 | /** |
---|
2192 | * Swapout transfer to the driver. The driver will break this I/O into groups |
---|
2193 | * of consecutive write requests is multiple consecutive buffers are required |
---|
2194 | * by the driver. The cache is not locked. |
---|
2195 | * |
---|
2196 | * @param transfer The transfer transaction. |
---|
2197 | */ |
---|
2198 | static void |
---|
2199 | rtems_bdbuf_swapout_write (rtems_bdbuf_swapout_transfer* transfer) |
---|
2200 | { |
---|
2201 | rtems_chain_node *node; |
---|
2202 | |
---|
2203 | if (rtems_bdbuf_tracer) |
---|
2204 | printf ("bdbuf:swapout transfer: %08x\n", (unsigned) transfer->dd->dev); |
---|
2205 | |
---|
2206 | /* |
---|
2207 | * If there are buffers to transfer to the media transfer them. |
---|
2208 | */ |
---|
2209 | if (!rtems_chain_is_empty (&transfer->bds)) |
---|
2210 | { |
---|
2211 | /* |
---|
2212 | * The last block number used when the driver only supports |
---|
2213 | * continuous blocks in a single request. |
---|
2214 | */ |
---|
2215 | uint32_t last_block = 0; |
---|
2216 | |
---|
2217 | /* |
---|
2218 | * Number of buffers per bd. This is used to detect the next |
---|
2219 | * block. |
---|
2220 | */ |
---|
2221 | uint32_t bufs_per_bd = 0; |
---|
2222 | |
---|
2223 | const rtems_disk_device *dd = transfer->dd; |
---|
2224 | |
---|
2225 | bufs_per_bd = dd->block_size / bdbuf_config.buffer_min; |
---|
2226 | |
---|
2227 | /* |
---|
2228 | * Take as many buffers as configured and pass to the driver. Note, the |
---|
2229 | * API to the drivers has an array of buffers and if a chain was passed |
---|
2230 | * we could have just passed the list. If the driver API is updated it |
---|
2231 | * should be possible to make this change with little effect in this |
---|
2232 | * code. The array that is passed is broken in design and should be |
---|
2233 | * removed. Merging members of a struct into the first member is |
---|
2234 | * trouble waiting to happen. |
---|
2235 | */ |
---|
2236 | transfer->write_req->status = RTEMS_RESOURCE_IN_USE; |
---|
2237 | transfer->write_req->bufnum = 0; |
---|
2238 | |
---|
2239 | while ((node = rtems_chain_get_unprotected(&transfer->bds)) != NULL) |
---|
2240 | { |
---|
2241 | rtems_bdbuf_buffer* bd = (rtems_bdbuf_buffer*) node; |
---|
2242 | bool write = false; |
---|
2243 | |
---|
2244 | /* |
---|
2245 | * If the device only accepts sequential buffers and this is not the |
---|
2246 | * first buffer (the first is always sequential, and the buffer is not |
---|
2247 | * sequential then put the buffer back on the transfer chain and write |
---|
2248 | * the committed buffers. |
---|
2249 | */ |
---|
2250 | |
---|
2251 | if (rtems_bdbuf_tracer) |
---|
2252 | printf ("bdbuf:swapout write: bd:%" PRIu32 ", bufnum:%" PRIu32 " mode:%s\n", |
---|
2253 | bd->block, transfer->write_req->bufnum, |
---|
2254 | dd->phys_dev->capabilities & |
---|
2255 | RTEMS_BLKDEV_CAP_MULTISECTOR_CONT ? "MULIT" : "SCAT"); |
---|
2256 | |
---|
2257 | if ((dd->phys_dev->capabilities & RTEMS_BLKDEV_CAP_MULTISECTOR_CONT) && |
---|
2258 | transfer->write_req->bufnum && |
---|
2259 | (bd->block != (last_block + bufs_per_bd))) |
---|
2260 | { |
---|
2261 | rtems_chain_prepend_unprotected (&transfer->bds, &bd->link); |
---|
2262 | write = true; |
---|
2263 | } |
---|
2264 | else |
---|
2265 | { |
---|
2266 | rtems_blkdev_sg_buffer* buf; |
---|
2267 | buf = &transfer->write_req->bufs[transfer->write_req->bufnum]; |
---|
2268 | transfer->write_req->bufnum++; |
---|
2269 | buf->user = bd; |
---|
2270 | buf->block = bd->block; |
---|
2271 | buf->length = dd->block_size; |
---|
2272 | buf->buffer = bd->buffer; |
---|
2273 | last_block = bd->block; |
---|
2274 | } |
---|
2275 | |
---|
2276 | /* |
---|
2277 | * Perform the transfer if there are no more buffers, or the transfer |
---|
2278 | * size has reached the configured max. value. |
---|
2279 | */ |
---|
2280 | |
---|
2281 | if (rtems_chain_is_empty (&transfer->bds) || |
---|
2282 | (transfer->write_req->bufnum >= bdbuf_config.max_write_blocks)) |
---|
2283 | write = true; |
---|
2284 | |
---|
2285 | if (write) |
---|
2286 | { |
---|
2287 | rtems_bdbuf_execute_transfer_request (dd, transfer->write_req, false); |
---|
2288 | |
---|
2289 | transfer->write_req->status = RTEMS_RESOURCE_IN_USE; |
---|
2290 | transfer->write_req->bufnum = 0; |
---|
2291 | } |
---|
2292 | } |
---|
2293 | |
---|
2294 | /* |
---|
2295 | * If sync'ing and the deivce is capability of handling a sync IO control |
---|
2296 | * call perform the call. |
---|
2297 | */ |
---|
2298 | if (transfer->syncing && |
---|
2299 | (dd->phys_dev->capabilities & RTEMS_BLKDEV_CAP_SYNC)) |
---|
2300 | { |
---|
2301 | /* int result = */ dd->ioctl (dd->phys_dev, RTEMS_BLKDEV_REQ_SYNC, NULL); |
---|
2302 | /* How should the error be handled ? */ |
---|
2303 | } |
---|
2304 | } |
---|
2305 | } |
---|
2306 | |
---|
2307 | /** |
---|
2308 | * Process the modified list of buffers. There is a sync or modified list that |
---|
2309 | * needs to be handled so we have a common function to do the work. |
---|
2310 | * |
---|
2311 | * @param dd_ptr Pointer to the device to handle. If BDBUF_INVALID_DEV no |
---|
2312 | * device is selected so select the device of the first buffer to be written to |
---|
2313 | * disk. |
---|
2314 | * @param chain The modified chain to process. |
---|
2315 | * @param transfer The chain to append buffers to be written too. |
---|
2316 | * @param sync_active If true this is a sync operation so expire all timers. |
---|
2317 | * @param update_timers If true update the timers. |
---|
2318 | * @param timer_delta It update_timers is true update the timers by this |
---|
2319 | * amount. |
---|
2320 | */ |
---|
2321 | static void |
---|
2322 | rtems_bdbuf_swapout_modified_processing (const rtems_disk_device **dd_ptr, |
---|
2323 | rtems_chain_control* chain, |
---|
2324 | rtems_chain_control* transfer, |
---|
2325 | bool sync_active, |
---|
2326 | bool update_timers, |
---|
2327 | uint32_t timer_delta) |
---|
2328 | { |
---|
2329 | if (!rtems_chain_is_empty (chain)) |
---|
2330 | { |
---|
2331 | rtems_chain_node* node = rtems_chain_head (chain); |
---|
2332 | bool sync_all; |
---|
2333 | |
---|
2334 | node = node->next; |
---|
2335 | |
---|
2336 | /* |
---|
2337 | * A sync active with no valid dev means sync all. |
---|
2338 | */ |
---|
2339 | if (sync_active && (*dd_ptr == BDBUF_INVALID_DEV)) |
---|
2340 | sync_all = true; |
---|
2341 | else |
---|
2342 | sync_all = false; |
---|
2343 | |
---|
2344 | while (!rtems_chain_is_tail (chain, node)) |
---|
2345 | { |
---|
2346 | rtems_bdbuf_buffer* bd = (rtems_bdbuf_buffer*) node; |
---|
2347 | |
---|
2348 | /* |
---|
2349 | * Check if the buffer's hold timer has reached 0. If a sync is active |
---|
2350 | * or someone waits for a buffer written force all the timers to 0. |
---|
2351 | * |
---|
2352 | * @note Lots of sync requests will skew this timer. It should be based |
---|
2353 | * on TOD to be accurate. Does it matter ? |
---|
2354 | */ |
---|
2355 | if (sync_all || (sync_active && (*dd_ptr == bd->dd)) |
---|
2356 | || rtems_bdbuf_has_buffer_waiters ()) |
---|
2357 | bd->hold_timer = 0; |
---|
2358 | |
---|
2359 | if (bd->hold_timer) |
---|
2360 | { |
---|
2361 | if (update_timers) |
---|
2362 | { |
---|
2363 | if (bd->hold_timer > timer_delta) |
---|
2364 | bd->hold_timer -= timer_delta; |
---|
2365 | else |
---|
2366 | bd->hold_timer = 0; |
---|
2367 | } |
---|
2368 | |
---|
2369 | if (bd->hold_timer) |
---|
2370 | { |
---|
2371 | node = node->next; |
---|
2372 | continue; |
---|
2373 | } |
---|
2374 | } |
---|
2375 | |
---|
2376 | /* |
---|
2377 | * This assumes we can set it to BDBUF_INVALID_DEV which is just an |
---|
2378 | * assumption. Cannot use the transfer list being empty the sync dev |
---|
2379 | * calls sets the dev to use. |
---|
2380 | */ |
---|
2381 | if (*dd_ptr == BDBUF_INVALID_DEV) |
---|
2382 | *dd_ptr = bd->dd; |
---|
2383 | |
---|
2384 | if (bd->dd == *dd_ptr) |
---|
2385 | { |
---|
2386 | rtems_chain_node* next_node = node->next; |
---|
2387 | rtems_chain_node* tnode = rtems_chain_tail (transfer); |
---|
2388 | |
---|
2389 | /* |
---|
2390 | * The blocks on the transfer list are sorted in block order. This |
---|
2391 | * means multi-block transfers for drivers that require consecutive |
---|
2392 | * blocks perform better with sorted blocks and for real disks it may |
---|
2393 | * help lower head movement. |
---|
2394 | */ |
---|
2395 | |
---|
2396 | rtems_bdbuf_set_state (bd, RTEMS_BDBUF_STATE_TRANSFER); |
---|
2397 | |
---|
2398 | rtems_chain_extract_unprotected (node); |
---|
2399 | |
---|
2400 | tnode = tnode->previous; |
---|
2401 | |
---|
2402 | while (node && !rtems_chain_is_head (transfer, tnode)) |
---|
2403 | { |
---|
2404 | rtems_bdbuf_buffer* tbd = (rtems_bdbuf_buffer*) tnode; |
---|
2405 | |
---|
2406 | if (bd->block > tbd->block) |
---|
2407 | { |
---|
2408 | rtems_chain_insert_unprotected (tnode, node); |
---|
2409 | node = NULL; |
---|
2410 | } |
---|
2411 | else |
---|
2412 | tnode = tnode->previous; |
---|
2413 | } |
---|
2414 | |
---|
2415 | if (node) |
---|
2416 | rtems_chain_prepend_unprotected (transfer, node); |
---|
2417 | |
---|
2418 | node = next_node; |
---|
2419 | } |
---|
2420 | else |
---|
2421 | { |
---|
2422 | node = node->next; |
---|
2423 | } |
---|
2424 | } |
---|
2425 | } |
---|
2426 | } |
---|
2427 | |
---|
2428 | /** |
---|
2429 | * Process the cache's modified buffers. Check the sync list first then the |
---|
2430 | * modified list extracting the buffers suitable to be written to disk. We have |
---|
2431 | * a device at a time. The task level loop will repeat this operation while |
---|
2432 | * there are buffers to be written. If the transfer fails place the buffers |
---|
2433 | * back on the modified list and try again later. The cache is unlocked while |
---|
2434 | * the buffers are being written to disk. |
---|
2435 | * |
---|
2436 | * @param timer_delta It update_timers is true update the timers by this |
---|
2437 | * amount. |
---|
2438 | * @param update_timers If true update the timers. |
---|
2439 | * @param transfer The transfer transaction data. |
---|
2440 | * |
---|
2441 | * @retval true Buffers where written to disk so scan again. |
---|
2442 | * @retval false No buffers where written to disk. |
---|
2443 | */ |
---|
2444 | static bool |
---|
2445 | rtems_bdbuf_swapout_processing (unsigned long timer_delta, |
---|
2446 | bool update_timers, |
---|
2447 | rtems_bdbuf_swapout_transfer* transfer) |
---|
2448 | { |
---|
2449 | rtems_bdbuf_swapout_worker* worker; |
---|
2450 | bool transfered_buffers = false; |
---|
2451 | |
---|
2452 | rtems_bdbuf_lock_cache (); |
---|
2453 | |
---|
2454 | /* |
---|
2455 | * If a sync is active do not use a worker because the current code does not |
---|
2456 | * cleaning up after. We need to know the buffers have been written when |
---|
2457 | * syncing to release sync lock and currently worker threads do not return to |
---|
2458 | * here. We do not know the worker is the last in a sequence of sync writes |
---|
2459 | * until after we have it running so we do not know to tell it to release the |
---|
2460 | * lock. The simplest solution is to get the main swap out task perform all |
---|
2461 | * sync operations. |
---|
2462 | */ |
---|
2463 | if (bdbuf_cache.sync_active) |
---|
2464 | worker = NULL; |
---|
2465 | else |
---|
2466 | { |
---|
2467 | worker = (rtems_bdbuf_swapout_worker*) |
---|
2468 | rtems_chain_get_unprotected (&bdbuf_cache.swapout_workers); |
---|
2469 | if (worker) |
---|
2470 | transfer = &worker->transfer; |
---|
2471 | } |
---|
2472 | |
---|
2473 | rtems_chain_initialize_empty (&transfer->bds); |
---|
2474 | transfer->dd = BDBUF_INVALID_DEV; |
---|
2475 | transfer->syncing = bdbuf_cache.sync_active; |
---|
2476 | |
---|
2477 | /* |
---|
2478 | * When the sync is for a device limit the sync to that device. If the sync |
---|
2479 | * is for a buffer handle process the devices in the order on the sync |
---|
2480 | * list. This means the dev is BDBUF_INVALID_DEV. |
---|
2481 | */ |
---|
2482 | if (bdbuf_cache.sync_active) |
---|
2483 | transfer->dd = bdbuf_cache.sync_device; |
---|
2484 | |
---|
2485 | /* |
---|
2486 | * If we have any buffers in the sync queue move them to the modified |
---|
2487 | * list. The first sync buffer will select the device we use. |
---|
2488 | */ |
---|
2489 | rtems_bdbuf_swapout_modified_processing (&transfer->dd, |
---|
2490 | &bdbuf_cache.sync, |
---|
2491 | &transfer->bds, |
---|
2492 | true, false, |
---|
2493 | timer_delta); |
---|
2494 | |
---|
2495 | /* |
---|
2496 | * Process the cache's modified list. |
---|
2497 | */ |
---|
2498 | rtems_bdbuf_swapout_modified_processing (&transfer->dd, |
---|
2499 | &bdbuf_cache.modified, |
---|
2500 | &transfer->bds, |
---|
2501 | bdbuf_cache.sync_active, |
---|
2502 | update_timers, |
---|
2503 | timer_delta); |
---|
2504 | |
---|
2505 | /* |
---|
2506 | * We have all the buffers that have been modified for this device so the |
---|
2507 | * cache can be unlocked because the state of each buffer has been set to |
---|
2508 | * TRANSFER. |
---|
2509 | */ |
---|
2510 | rtems_bdbuf_unlock_cache (); |
---|
2511 | |
---|
2512 | /* |
---|
2513 | * If there are buffers to transfer to the media transfer them. |
---|
2514 | */ |
---|
2515 | if (!rtems_chain_is_empty (&transfer->bds)) |
---|
2516 | { |
---|
2517 | if (worker) |
---|
2518 | { |
---|
2519 | rtems_status_code sc = rtems_event_send (worker->id, |
---|
2520 | RTEMS_BDBUF_SWAPOUT_SYNC); |
---|
2521 | if (sc != RTEMS_SUCCESSFUL) |
---|
2522 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_SO_WAKE); |
---|
2523 | } |
---|
2524 | else |
---|
2525 | { |
---|
2526 | rtems_bdbuf_swapout_write (transfer); |
---|
2527 | } |
---|
2528 | |
---|
2529 | transfered_buffers = true; |
---|
2530 | } |
---|
2531 | |
---|
2532 | if (bdbuf_cache.sync_active && !transfered_buffers) |
---|
2533 | { |
---|
2534 | rtems_id sync_requester; |
---|
2535 | rtems_bdbuf_lock_cache (); |
---|
2536 | sync_requester = bdbuf_cache.sync_requester; |
---|
2537 | bdbuf_cache.sync_active = false; |
---|
2538 | bdbuf_cache.sync_requester = 0; |
---|
2539 | rtems_bdbuf_unlock_cache (); |
---|
2540 | if (sync_requester) |
---|
2541 | rtems_event_send (sync_requester, RTEMS_BDBUF_TRANSFER_SYNC); |
---|
2542 | } |
---|
2543 | |
---|
2544 | return transfered_buffers; |
---|
2545 | } |
---|
2546 | |
---|
2547 | /** |
---|
2548 | * Allocate the write request and initialise it for good measure. |
---|
2549 | * |
---|
2550 | * @return rtems_blkdev_request* The write reference memory. |
---|
2551 | */ |
---|
2552 | static rtems_blkdev_request* |
---|
2553 | rtems_bdbuf_swapout_writereq_alloc (void) |
---|
2554 | { |
---|
2555 | /* |
---|
2556 | * @note chrisj The rtems_blkdev_request and the array at the end is a hack. |
---|
2557 | * I am disappointment at finding code like this in RTEMS. The request should |
---|
2558 | * have been a rtems_chain_control. Simple, fast and less storage as the node |
---|
2559 | * is already part of the buffer structure. |
---|
2560 | */ |
---|
2561 | rtems_blkdev_request* write_req = |
---|
2562 | malloc (sizeof (rtems_blkdev_request) + |
---|
2563 | (bdbuf_config.max_write_blocks * sizeof (rtems_blkdev_sg_buffer))); |
---|
2564 | |
---|
2565 | if (!write_req) |
---|
2566 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_SO_NOMEM); |
---|
2567 | |
---|
2568 | write_req->req = RTEMS_BLKDEV_REQ_WRITE; |
---|
2569 | write_req->req_done = rtems_bdbuf_transfer_done; |
---|
2570 | write_req->done_arg = write_req; |
---|
2571 | write_req->io_task = rtems_task_self (); |
---|
2572 | |
---|
2573 | return write_req; |
---|
2574 | } |
---|
2575 | |
---|
2576 | /** |
---|
2577 | * The swapout worker thread body. |
---|
2578 | * |
---|
2579 | * @param arg A pointer to the worker thread's private data. |
---|
2580 | * @return rtems_task Not used. |
---|
2581 | */ |
---|
2582 | static rtems_task |
---|
2583 | rtems_bdbuf_swapout_worker_task (rtems_task_argument arg) |
---|
2584 | { |
---|
2585 | rtems_bdbuf_swapout_worker* worker = (rtems_bdbuf_swapout_worker*) arg; |
---|
2586 | |
---|
2587 | while (worker->enabled) |
---|
2588 | { |
---|
2589 | rtems_bdbuf_wait_for_event (RTEMS_BDBUF_SWAPOUT_SYNC); |
---|
2590 | |
---|
2591 | rtems_bdbuf_swapout_write (&worker->transfer); |
---|
2592 | |
---|
2593 | rtems_bdbuf_lock_cache (); |
---|
2594 | |
---|
2595 | rtems_chain_initialize_empty (&worker->transfer.bds); |
---|
2596 | worker->transfer.dd = BDBUF_INVALID_DEV; |
---|
2597 | |
---|
2598 | rtems_chain_append_unprotected (&bdbuf_cache.swapout_workers, &worker->link); |
---|
2599 | |
---|
2600 | rtems_bdbuf_unlock_cache (); |
---|
2601 | } |
---|
2602 | |
---|
2603 | free (worker->transfer.write_req); |
---|
2604 | free (worker); |
---|
2605 | |
---|
2606 | rtems_task_delete (RTEMS_SELF); |
---|
2607 | } |
---|
2608 | |
---|
2609 | /** |
---|
2610 | * Open the swapout worker threads. |
---|
2611 | */ |
---|
2612 | static void |
---|
2613 | rtems_bdbuf_swapout_workers_open (void) |
---|
2614 | { |
---|
2615 | rtems_status_code sc; |
---|
2616 | size_t w; |
---|
2617 | |
---|
2618 | rtems_bdbuf_lock_cache (); |
---|
2619 | |
---|
2620 | for (w = 0; w < bdbuf_config.swapout_workers; w++) |
---|
2621 | { |
---|
2622 | rtems_bdbuf_swapout_worker* worker; |
---|
2623 | |
---|
2624 | worker = malloc (sizeof (rtems_bdbuf_swapout_worker)); |
---|
2625 | if (!worker) |
---|
2626 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_SO_NOMEM); |
---|
2627 | |
---|
2628 | rtems_chain_append_unprotected (&bdbuf_cache.swapout_workers, &worker->link); |
---|
2629 | worker->enabled = true; |
---|
2630 | worker->transfer.write_req = rtems_bdbuf_swapout_writereq_alloc (); |
---|
2631 | |
---|
2632 | rtems_chain_initialize_empty (&worker->transfer.bds); |
---|
2633 | worker->transfer.dd = BDBUF_INVALID_DEV; |
---|
2634 | |
---|
2635 | sc = rtems_task_create (rtems_build_name('B', 'D', 'o', 'a' + w), |
---|
2636 | (bdbuf_config.swapout_priority ? |
---|
2637 | bdbuf_config.swapout_priority : |
---|
2638 | RTEMS_BDBUF_SWAPOUT_TASK_PRIORITY_DEFAULT), |
---|
2639 | SWAPOUT_TASK_STACK_SIZE, |
---|
2640 | RTEMS_PREEMPT | RTEMS_NO_TIMESLICE | RTEMS_NO_ASR, |
---|
2641 | RTEMS_LOCAL | RTEMS_NO_FLOATING_POINT, |
---|
2642 | &worker->id); |
---|
2643 | if (sc != RTEMS_SUCCESSFUL) |
---|
2644 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_SO_WK_CREATE); |
---|
2645 | |
---|
2646 | sc = rtems_task_start (worker->id, |
---|
2647 | rtems_bdbuf_swapout_worker_task, |
---|
2648 | (rtems_task_argument) worker); |
---|
2649 | if (sc != RTEMS_SUCCESSFUL) |
---|
2650 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_SO_WK_START); |
---|
2651 | } |
---|
2652 | |
---|
2653 | rtems_bdbuf_unlock_cache (); |
---|
2654 | } |
---|
2655 | |
---|
2656 | /** |
---|
2657 | * Close the swapout worker threads. |
---|
2658 | */ |
---|
2659 | static void |
---|
2660 | rtems_bdbuf_swapout_workers_close (void) |
---|
2661 | { |
---|
2662 | rtems_chain_node* node; |
---|
2663 | |
---|
2664 | rtems_bdbuf_lock_cache (); |
---|
2665 | |
---|
2666 | node = rtems_chain_first (&bdbuf_cache.swapout_workers); |
---|
2667 | while (!rtems_chain_is_tail (&bdbuf_cache.swapout_workers, node)) |
---|
2668 | { |
---|
2669 | rtems_bdbuf_swapout_worker* worker = (rtems_bdbuf_swapout_worker*) node; |
---|
2670 | worker->enabled = false; |
---|
2671 | rtems_event_send (worker->id, RTEMS_BDBUF_SWAPOUT_SYNC); |
---|
2672 | node = rtems_chain_next (node); |
---|
2673 | } |
---|
2674 | |
---|
2675 | rtems_bdbuf_unlock_cache (); |
---|
2676 | } |
---|
2677 | |
---|
2678 | /** |
---|
2679 | * Body of task which takes care on flushing modified buffers to the disk. |
---|
2680 | * |
---|
2681 | * @param arg A pointer to the global cache data. Use the global variable and |
---|
2682 | * not this. |
---|
2683 | * @return rtems_task Not used. |
---|
2684 | */ |
---|
2685 | static rtems_task |
---|
2686 | rtems_bdbuf_swapout_task (rtems_task_argument arg) |
---|
2687 | { |
---|
2688 | rtems_bdbuf_swapout_transfer transfer; |
---|
2689 | uint32_t period_in_ticks; |
---|
2690 | const uint32_t period_in_msecs = bdbuf_config.swapout_period;; |
---|
2691 | uint32_t timer_delta; |
---|
2692 | |
---|
2693 | transfer.write_req = rtems_bdbuf_swapout_writereq_alloc (); |
---|
2694 | rtems_chain_initialize_empty (&transfer.bds); |
---|
2695 | transfer.dd = BDBUF_INVALID_DEV; |
---|
2696 | transfer.syncing = false; |
---|
2697 | |
---|
2698 | /* |
---|
2699 | * Localise the period. |
---|
2700 | */ |
---|
2701 | period_in_ticks = RTEMS_MICROSECONDS_TO_TICKS (period_in_msecs * 1000); |
---|
2702 | |
---|
2703 | /* |
---|
2704 | * This is temporary. Needs to be changed to use the real time clock. |
---|
2705 | */ |
---|
2706 | timer_delta = period_in_msecs; |
---|
2707 | |
---|
2708 | /* |
---|
2709 | * Create the worker threads. |
---|
2710 | */ |
---|
2711 | rtems_bdbuf_swapout_workers_open (); |
---|
2712 | |
---|
2713 | while (bdbuf_cache.swapout_enabled) |
---|
2714 | { |
---|
2715 | rtems_event_set out; |
---|
2716 | rtems_status_code sc; |
---|
2717 | |
---|
2718 | /* |
---|
2719 | * Only update the timers once in the processing cycle. |
---|
2720 | */ |
---|
2721 | bool update_timers = true; |
---|
2722 | |
---|
2723 | /* |
---|
2724 | * If we write buffers to any disk perform a check again. We only write a |
---|
2725 | * single device at a time and the cache may have more than one device's |
---|
2726 | * buffers modified waiting to be written. |
---|
2727 | */ |
---|
2728 | bool transfered_buffers; |
---|
2729 | |
---|
2730 | do |
---|
2731 | { |
---|
2732 | transfered_buffers = false; |
---|
2733 | |
---|
2734 | /* |
---|
2735 | * Extact all the buffers we find for a specific device. The device is |
---|
2736 | * the first one we find on a modified list. Process the sync queue of |
---|
2737 | * buffers first. |
---|
2738 | */ |
---|
2739 | if (rtems_bdbuf_swapout_processing (timer_delta, |
---|
2740 | update_timers, |
---|
2741 | &transfer)) |
---|
2742 | { |
---|
2743 | transfered_buffers = true; |
---|
2744 | } |
---|
2745 | |
---|
2746 | /* |
---|
2747 | * Only update the timers once. |
---|
2748 | */ |
---|
2749 | update_timers = false; |
---|
2750 | } |
---|
2751 | while (transfered_buffers); |
---|
2752 | |
---|
2753 | sc = rtems_event_receive (RTEMS_BDBUF_SWAPOUT_SYNC, |
---|
2754 | RTEMS_EVENT_ALL | RTEMS_WAIT, |
---|
2755 | period_in_ticks, |
---|
2756 | &out); |
---|
2757 | |
---|
2758 | if ((sc != RTEMS_SUCCESSFUL) && (sc != RTEMS_TIMEOUT)) |
---|
2759 | rtems_fatal_error_occurred (BLKDEV_FATAL_BDBUF_SWAPOUT_RE); |
---|
2760 | } |
---|
2761 | |
---|
2762 | rtems_bdbuf_swapout_workers_close (); |
---|
2763 | |
---|
2764 | free (transfer.write_req); |
---|
2765 | |
---|
2766 | rtems_task_delete (RTEMS_SELF); |
---|
2767 | } |
---|
2768 | |
---|
2769 | static void |
---|
2770 | rtems_bdbuf_purge_list (rtems_chain_control *purge_list) |
---|
2771 | { |
---|
2772 | bool wake_buffer_waiters = false; |
---|
2773 | rtems_chain_node *node = NULL; |
---|
2774 | |
---|
2775 | while ((node = rtems_chain_get_unprotected (purge_list)) != NULL) |
---|
2776 | { |
---|
2777 | rtems_bdbuf_buffer *bd = (rtems_bdbuf_buffer *) node; |
---|
2778 | |
---|
2779 | if (bd->waiters == 0) |
---|
2780 | wake_buffer_waiters = true; |
---|
2781 | |
---|
2782 | rtems_bdbuf_discard_buffer (bd); |
---|
2783 | } |
---|
2784 | |
---|
2785 | if (wake_buffer_waiters) |
---|
2786 | rtems_bdbuf_wake (&bdbuf_cache.buffer_waiters); |
---|
2787 | } |
---|
2788 | |
---|
2789 | static void |
---|
2790 | rtems_bdbuf_gather_for_purge (rtems_chain_control *purge_list, |
---|
2791 | const rtems_disk_device *dd) |
---|
2792 | { |
---|
2793 | rtems_bdbuf_buffer *stack [RTEMS_BDBUF_AVL_MAX_HEIGHT]; |
---|
2794 | rtems_bdbuf_buffer **prev = stack; |
---|
2795 | rtems_bdbuf_buffer *cur = bdbuf_cache.tree; |
---|
2796 | |
---|
2797 | *prev = NULL; |
---|
2798 | |
---|
2799 | while (cur != NULL) |
---|
2800 | { |
---|
2801 | if (cur->dd == dd) |
---|
2802 | { |
---|
2803 | switch (cur->state) |
---|
2804 | { |
---|
2805 | case RTEMS_BDBUF_STATE_FREE: |
---|
2806 | case RTEMS_BDBUF_STATE_EMPTY: |
---|
2807 | case RTEMS_BDBUF_STATE_ACCESS_PURGED: |
---|
2808 | case RTEMS_BDBUF_STATE_TRANSFER_PURGED: |
---|
2809 | break; |
---|
2810 | case RTEMS_BDBUF_STATE_SYNC: |
---|
2811 | rtems_bdbuf_wake (&bdbuf_cache.transfer_waiters); |
---|
2812 | /* Fall through */ |
---|
2813 | case RTEMS_BDBUF_STATE_MODIFIED: |
---|
2814 | rtems_bdbuf_group_release (cur); |
---|
2815 | /* Fall through */ |
---|
2816 | case RTEMS_BDBUF_STATE_CACHED: |
---|
2817 | rtems_chain_extract_unprotected (&cur->link); |
---|
2818 | rtems_chain_append_unprotected (purge_list, &cur->link); |
---|
2819 | break; |
---|
2820 | case RTEMS_BDBUF_STATE_TRANSFER: |
---|
2821 | rtems_bdbuf_set_state (cur, RTEMS_BDBUF_STATE_TRANSFER_PURGED); |
---|
2822 | break; |
---|
2823 | case RTEMS_BDBUF_STATE_ACCESS_CACHED: |
---|
2824 | case RTEMS_BDBUF_STATE_ACCESS_EMPTY: |
---|
2825 | case RTEMS_BDBUF_STATE_ACCESS_MODIFIED: |
---|
2826 | rtems_bdbuf_set_state (cur, RTEMS_BDBUF_STATE_ACCESS_PURGED); |
---|
2827 | break; |
---|
2828 | default: |
---|
2829 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_STATE_11); |
---|
2830 | } |
---|
2831 | } |
---|
2832 | |
---|
2833 | if (cur->avl.left != NULL) |
---|
2834 | { |
---|
2835 | /* Left */ |
---|
2836 | ++prev; |
---|
2837 | *prev = cur; |
---|
2838 | cur = cur->avl.left; |
---|
2839 | } |
---|
2840 | else if (cur->avl.right != NULL) |
---|
2841 | { |
---|
2842 | /* Right */ |
---|
2843 | ++prev; |
---|
2844 | *prev = cur; |
---|
2845 | cur = cur->avl.right; |
---|
2846 | } |
---|
2847 | else |
---|
2848 | { |
---|
2849 | while (*prev != NULL && cur == (*prev)->avl.right) |
---|
2850 | { |
---|
2851 | /* Up */ |
---|
2852 | cur = *prev; |
---|
2853 | --prev; |
---|
2854 | } |
---|
2855 | if (*prev != NULL) |
---|
2856 | /* Right */ |
---|
2857 | cur = (*prev)->avl.right; |
---|
2858 | else |
---|
2859 | /* Finished */ |
---|
2860 | cur = NULL; |
---|
2861 | } |
---|
2862 | } |
---|
2863 | } |
---|
2864 | |
---|
2865 | void |
---|
2866 | rtems_bdbuf_purge_dev (const rtems_disk_device *dd) |
---|
2867 | { |
---|
2868 | rtems_chain_control purge_list; |
---|
2869 | |
---|
2870 | rtems_chain_initialize_empty (&purge_list); |
---|
2871 | rtems_bdbuf_lock_cache (); |
---|
2872 | rtems_bdbuf_gather_for_purge (&purge_list, dd); |
---|
2873 | rtems_bdbuf_purge_list (&purge_list); |
---|
2874 | rtems_bdbuf_unlock_cache (); |
---|
2875 | } |
---|
2876 | |
---|
2877 | rtems_status_code |
---|
2878 | rtems_bdbuf_set_block_size (rtems_disk_device *dd, uint32_t block_size) |
---|
2879 | { |
---|
2880 | rtems_status_code sc = RTEMS_SUCCESSFUL; |
---|
2881 | |
---|
2882 | rtems_bdbuf_lock_cache (); |
---|
2883 | |
---|
2884 | if (block_size > 0) |
---|
2885 | { |
---|
2886 | size_t bds_per_group = rtems_bdbuf_bds_per_group (block_size); |
---|
2887 | |
---|
2888 | if (bds_per_group != 0) |
---|
2889 | { |
---|
2890 | int block_to_media_block_shift = 0; |
---|
2891 | uint32_t media_blocks_per_block = block_size / dd->media_block_size; |
---|
2892 | uint32_t one = 1; |
---|
2893 | |
---|
2894 | while ((one << block_to_media_block_shift) < media_blocks_per_block) |
---|
2895 | { |
---|
2896 | ++block_to_media_block_shift; |
---|
2897 | } |
---|
2898 | |
---|
2899 | if ((dd->media_block_size << block_to_media_block_shift) != block_size) |
---|
2900 | block_to_media_block_shift = -1; |
---|
2901 | |
---|
2902 | dd->block_size = block_size; |
---|
2903 | dd->block_to_media_block_shift = block_to_media_block_shift; |
---|
2904 | dd->bds_per_group = bds_per_group; |
---|
2905 | } |
---|
2906 | else |
---|
2907 | { |
---|
2908 | sc = RTEMS_INVALID_NUMBER; |
---|
2909 | } |
---|
2910 | } |
---|
2911 | else |
---|
2912 | { |
---|
2913 | sc = RTEMS_INVALID_NUMBER; |
---|
2914 | } |
---|
2915 | |
---|
2916 | rtems_bdbuf_unlock_cache (); |
---|
2917 | |
---|
2918 | return sc; |
---|
2919 | } |
---|