1 | /** |
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2 | * @file rtems/blkdev.h |
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3 | * block device driver interface definitions |
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4 | */ |
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5 | |
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6 | /* |
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7 | * Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia |
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8 | * Author: Victor V. Vengerov <vvv@oktet.ru> |
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9 | * |
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10 | * @(#) $Id$ |
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11 | */ |
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12 | |
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13 | #ifndef _RTEMS_BLKDEV_H |
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14 | #define _RTEMS_BLKDEV_H |
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15 | |
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16 | #include <rtems.h> |
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17 | #include <sys/ioctl.h> |
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18 | |
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19 | #ifdef __cplusplus |
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20 | extern "C" { |
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21 | #endif |
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22 | |
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23 | /* Interface with device drivers |
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24 | * Block device looks, initialized and behaves like traditional RTEMS device |
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25 | * driver. Heart of the block device driver is in BIOREQUEST ioctl. This call |
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26 | * puts I/O request to the block device queue, in priority order, for |
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27 | * asynchronous processing. When driver executes request, req_done |
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28 | * function invoked, so callee knows about it. Look for details below. |
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29 | */ |
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30 | |
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31 | |
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32 | /* Block device block number datatype */ |
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33 | typedef uint32_t blkdev_bnum; |
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34 | |
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35 | /* Block device request type */ |
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36 | typedef enum blkdev_request_op { |
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37 | BLKDEV_REQ_READ, /* Read operation */ |
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38 | BLKDEV_REQ_WRITE /* Write operation */ |
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39 | } blkdev_request_op; |
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40 | |
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41 | /* Type for block device request done callback function. |
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42 | * |
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43 | * PARAMETERS: |
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44 | * arg - argument supplied in blkdev_request |
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45 | * status - rtems status code for this operation |
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46 | * errno - errno value to be passed to the user when |
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47 | * status != RTEMS_SUCCESSFUL |
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48 | */ |
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49 | typedef void (* blkdev_request_cb)(void *arg, |
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50 | rtems_status_code status, |
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51 | int error); |
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52 | |
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53 | /* blkdev_sg_buffer |
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54 | * Block device scatter/gather buffer structure |
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55 | */ |
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56 | typedef struct blkdev_sg_buffer { |
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57 | uint32_t length; /* Buffer length */ |
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58 | void *buffer; /* Buffer pointer */ |
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59 | } blkdev_sg_buffer; |
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60 | |
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61 | /* blkdev_request (Block Device Request) structure is |
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62 | * used to read/write a number of blocks from/to device. |
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63 | */ |
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64 | typedef struct blkdev_request { |
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65 | blkdev_request_op req; /* Block device operation (read or write) */ |
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66 | blkdev_request_cb req_done; /* Callback function */ |
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67 | void *done_arg; /* Argument to be passed to callback function*/ |
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68 | rtems_status_code status; /* Last I/O operation completion status */ |
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69 | int error; /* If status != RTEMS_SUCCESSFUL, this field |
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70 | * contains error code |
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71 | */ |
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72 | blkdev_bnum start; /* Start block number */ |
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73 | uint32_t count; /* Number of blocks to be exchanged */ |
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74 | uint32_t bufnum; /* Number of buffers provided */ |
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75 | |
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76 | blkdev_sg_buffer bufs[0];/* List of scatter/gather buffers */ |
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77 | } blkdev_request; |
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78 | |
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79 | /* Block device IOCTL request codes */ |
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80 | #define BLKIO_REQUEST _IOWR('B', 1, blkdev_request) |
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81 | #define BLKIO_GETBLKSIZE _IO('B', 2) |
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82 | #define BLKIO_GETSIZE _IO('B', 3) |
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83 | #define BLKIO_SYNCDEV _IO('B', 4) |
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84 | |
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85 | /* Device driver interface conventions suppose that driver may |
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86 | * contain initialize/open/close/read/write/ioctl entry points. These |
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87 | * primitives (except initialize) can be implemented in generic fashion, |
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88 | * based upon supplied block device driver ioctl handler. Every block |
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89 | * device driver should provide initialize entry point, which is register |
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90 | * all block devices and appropriate ioctl handlers. |
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91 | */ |
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92 | |
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93 | #define GENERIC_BLOCK_DEVICE_DRIVER_ENTRIES \ |
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94 | rtems_blkdev_generic_open, rtems_blkdev_generic_close, \ |
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95 | rtems_blkdev_generic_read, rtems_blkdev_generic_write, \ |
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96 | rtems_blkdev_generic_ioctl |
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97 | |
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98 | /* blkdev_generic_read -- |
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99 | * Generic block device read primitive. Implemented using block device |
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100 | * buffer management primitives. |
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101 | */ |
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102 | rtems_device_driver |
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103 | rtems_blkdev_generic_read( |
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104 | rtems_device_major_number major, |
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105 | rtems_device_minor_number minor, |
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106 | void * arg |
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107 | ); |
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108 | |
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109 | /* blkdev_generic_write -- |
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110 | * Generic block device driver write primitive. Implemented using block |
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111 | * device buffer management primitives. |
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112 | */ |
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113 | rtems_device_driver |
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114 | rtems_blkdev_generic_write( |
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115 | rtems_device_major_number major, |
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116 | rtems_device_minor_number minor, |
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117 | void * arg |
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118 | ); |
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119 | |
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120 | /* blkdev_generic_open -- |
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121 | * Generic block device open primitive. |
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122 | */ |
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123 | rtems_device_driver |
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124 | rtems_blkdev_generic_open( |
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125 | rtems_device_major_number major, |
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126 | rtems_device_minor_number minor, |
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127 | void * arg |
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128 | ); |
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129 | |
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130 | /* blkdev_generic_close -- |
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131 | * Generic block device close primitive. |
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132 | */ |
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133 | rtems_device_driver |
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134 | rtems_blkdev_generic_close( |
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135 | rtems_device_major_number major, |
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136 | rtems_device_minor_number minor, |
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137 | void * arg |
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138 | ); |
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139 | |
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140 | /* blkdev_generic_ioctl -- |
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141 | * Generic block device ioctl primitive. |
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142 | */ |
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143 | rtems_device_driver |
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144 | rtems_blkdev_generic_ioctl( |
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145 | rtems_device_major_number major, |
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146 | rtems_device_minor_number minor, |
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147 | void * arg |
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148 | ); |
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149 | |
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150 | #ifdef __cplusplus |
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151 | } |
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152 | #endif |
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153 | |
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154 | #endif |
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