[e51bd96] | 1 | /* |
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| 2 | * blkdev.h - block device driver interface definitions |
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| 3 | * |
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| 4 | * Copyright (C) 2001 OKTET Ltd., St.-Petersburg, Russia |
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| 5 | * Author: Victor V. Vengerov <vvv@oktet.ru> |
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| 6 | * |
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| 7 | * @(#) $Id$ |
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| 8 | */ |
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| 9 | |
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| 10 | #ifndef __RTEMS_LIBBLOCK_BLKDEV_H__ |
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| 11 | #define __RTEMS_LIBBLOCK_BLKDEV_H__ |
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| 12 | |
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| 13 | #include <rtems.h> |
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| 14 | #include <sys/ioctl.h> |
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| 15 | |
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| 16 | #ifdef __cplusplus |
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| 17 | extern "C" { |
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| 18 | #endif |
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| 19 | |
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| 20 | /* Interface with device drivers |
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| 21 | * Block device looks, initialized and behaves like traditional RTEMS device |
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| 22 | * driver. Heart of the block device driver is in BIOREQUEST ioctl. This call |
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| 23 | * puts I/O request to the block device queue, in priority order, for |
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| 24 | * asynchronous processing. When driver executes request, req_done |
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| 25 | * function invoked, so callee knows about it. Look for details below. |
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| 26 | */ |
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| 27 | |
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| 28 | |
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| 29 | /* Block device block number datatype */ |
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| 30 | typedef rtems_unsigned32 blkdev_bnum; |
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| 31 | |
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| 32 | /* Block device request type */ |
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| 33 | typedef enum blkdev_request_op { |
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| 34 | BLKDEV_REQ_READ, /* Read operation */ |
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| 35 | BLKDEV_REQ_WRITE /* Write operation */ |
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| 36 | } blkdev_request_op; |
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| 37 | |
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| 38 | /* Type for block device request done callback function. |
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| 39 | * |
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| 40 | * PARAMETERS: |
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| 41 | * arg - argument supplied in blkdev_request |
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| 42 | * status - rtems status code for this operation |
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| 43 | * errno - errno value to be passed to the user when |
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| 44 | * status != RTEMS_SUCCESSFUL |
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| 45 | */ |
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| 46 | typedef void (* blkdev_request_cb)(void *arg, |
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| 47 | rtems_status_code status, |
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| 48 | int error); |
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| 49 | |
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| 50 | /* blkdev_sg_buffer |
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| 51 | * Block device scatter/gather buffer structure |
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| 52 | */ |
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| 53 | typedef struct blkdev_sg_buffer { |
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| 54 | rtems_unsigned32 length; /* Buffer length */ |
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| 55 | void *buffer; /* Buffer pointer */ |
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| 56 | } blkdev_sg_buffer; |
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| 57 | |
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| 58 | /* blkdev_request (Block Device Request) structure is |
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| 59 | * used to read/write a number of blocks from/to device. |
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| 60 | */ |
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| 61 | typedef struct blkdev_request { |
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| 62 | blkdev_request_op req; /* Block device operation (read or write) */ |
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| 63 | blkdev_request_cb req_done; /* Callback function */ |
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| 64 | void *done_arg; /* Argument to be passed to callback function*/ |
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| 65 | blkdev_bnum start; /* Start block number */ |
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| 66 | rtems_unsigned32 count; /* Number of blocks to be exchanged */ |
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| 67 | rtems_unsigned32 bufnum; /* Number of buffers provided */ |
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| 68 | |
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| 69 | blkdev_sg_buffer bufs[0];/* List of scatter/gather buffers */ |
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| 70 | } blkdev_request; |
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| 71 | |
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| 72 | /* Block device IOCTL request codes */ |
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| 73 | #define BLKIO_REQUEST _IOWR('B', 1, blkdev_request) |
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| 74 | #define BLKIO_GETBLKSIZE _IO('B', 2) |
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| 75 | #define BLKIO_GETSIZE _IO('B', 3) |
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| 76 | #define BLKIO_SYNCDEV _IO('B', 4) |
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| 77 | |
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| 78 | /* Device driver interface conventions suppose that driver may |
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| 79 | * contain initialize/open/close/read/write/ioctl entry points. These |
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| 80 | * primitives (except initialize) can be implemented in generic fashion, |
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| 81 | * based upon supplied block device driver ioctl handler. Every block |
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| 82 | * device driver should provide initialize entry point, which is register |
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| 83 | * all block devices and appropriate ioctl handlers. |
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| 84 | */ |
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| 85 | |
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| 86 | #define GENERIC_BLOCK_DEVICE_DRIVER_ENTRIES \ |
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| 87 | rtems_blkdev_generic_open, rtems_blkdev_generic_close, \ |
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| 88 | rtems_blkdev_generic_read, rtems_blkdev_generic_write, \ |
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| 89 | rtems_blkdev_generic_ioctl |
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| 90 | |
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| 91 | /* blkdev_generic_read -- |
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| 92 | * Generic block device read primitive. Implemented using block device |
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| 93 | * buffer management primitives. |
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| 94 | */ |
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| 95 | rtems_device_driver |
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| 96 | rtems_blkdev_generic_read( |
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| 97 | rtems_device_major_number major, |
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| 98 | rtems_device_minor_number minor, |
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| 99 | void * arg |
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| 100 | ); |
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| 101 | |
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| 102 | /* blkdev_generic_write -- |
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| 103 | * Generic block device driver write primitive. Implemented using block |
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| 104 | * device buffer management primitives. |
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| 105 | */ |
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| 106 | rtems_device_driver |
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| 107 | rtems_blkdev_generic_write( |
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| 108 | rtems_device_major_number major, |
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| 109 | rtems_device_minor_number minor, |
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| 110 | void * arg |
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| 111 | ); |
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| 112 | |
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| 113 | /* blkdev_generic_open -- |
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| 114 | * Generic block device open primitive. |
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| 115 | */ |
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| 116 | rtems_device_driver |
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| 117 | rtems_blkdev_generic_open( |
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| 118 | rtems_device_major_number major, |
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| 119 | rtems_device_minor_number minor, |
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| 120 | void * arg |
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| 121 | ); |
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| 122 | |
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| 123 | /* blkdev_generic_close -- |
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| 124 | * Generic block device close primitive. |
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| 125 | */ |
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| 126 | rtems_device_driver |
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| 127 | rtems_blkdev_generic_close( |
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| 128 | rtems_device_major_number major, |
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| 129 | rtems_device_minor_number minor, |
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| 130 | void * arg |
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| 131 | ); |
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| 132 | |
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| 133 | /* blkdev_generic_ioctl -- |
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| 134 | * Generic block device ioctl primitive. |
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| 135 | */ |
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| 136 | rtems_device_driver |
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| 137 | rtems_blkdev_generic_ioctl( |
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| 138 | rtems_device_major_number major, |
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| 139 | rtems_device_minor_number minor, |
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| 140 | void * arg |
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| 141 | ); |
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| 142 | |
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| 143 | #ifdef __cplusplus |
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| 144 | } |
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| 145 | #endif |
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| 146 | |
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| 147 | #endif |
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