[57aa979] | 1 | /** |
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| 2 | * @file |
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| 3 | * |
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[4670d91] | 4 | * @ingroup rtems_bdbuf |
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| 5 | * |
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[57aa979] | 6 | * Block device buffer management. |
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| 7 | */ |
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| 8 | |
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[e51bd96] | 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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[df6348bb] | 16 | * Alexander Kukuta <kam@oktet.ru> |
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[e51bd96] | 17 | * |
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[0d15414e] | 18 | * Copyright (C) 2008,2009 Chris Johns <chrisj@rtems.org> |
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[c21c850e] | 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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[3d14a45] | 22 | * @(#) bdbuf.c,v 1.14 2004/04/17 08:15:17 ralf Exp |
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[e51bd96] | 23 | */ |
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| 24 | |
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[3899a537] | 25 | /** |
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| 26 | * Set to 1 to enable debug tracing. |
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| 27 | */ |
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| 28 | #define RTEMS_BDBUF_TRACE 0 |
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| 29 | |
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[006fa1ef] | 30 | #if HAVE_CONFIG_H |
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| 31 | #include "config.h" |
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| 32 | #endif |
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| 33 | |
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[253c3a1d] | 34 | #include <inttypes.h> |
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| 35 | |
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[e51bd96] | 36 | #include <rtems.h> |
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[3899a537] | 37 | #include <rtems/error.h> |
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[57aa979] | 38 | #include <rtems/malloc.h> |
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[e51bd96] | 39 | #include <limits.h> |
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| 40 | #include <errno.h> |
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| 41 | #include <assert.h> |
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[3899a537] | 42 | #include <stdio.h> |
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[0ebfac19] | 43 | |
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[3899a537] | 44 | #include "rtems/bdbuf.h" |
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[e51bd96] | 45 | |
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[0d15414e] | 46 | /* |
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| 47 | * Simpler label for this file. |
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| 48 | */ |
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| 49 | #define bdbuf_config rtems_bdbuf_configuration |
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| 50 | |
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| 51 | /** |
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| 52 | * A swapout transfer transaction data. This data is passed to a worked thread |
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| 53 | * to handle the write phase of the transfer. |
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| 54 | */ |
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| 55 | typedef struct rtems_bdbuf_swapout_transfer |
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| 56 | { |
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[eb649786] | 57 | rtems_chain_control bds; /**< The transfer list of BDs. */ |
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| 58 | dev_t dev; /**< The device the transfer is for. */ |
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| 59 | rtems_blkdev_request* write_req; /**< The write request array. */ |
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| 60 | uint32_t bufs_per_bd; /**< Number of buffers per bd. */ |
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[0d15414e] | 61 | } rtems_bdbuf_swapout_transfer; |
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| 62 | |
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| 63 | /** |
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| 64 | * Swapout worker thread. These are available to take processing from the |
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| 65 | * main swapout thread and handle the I/O operation. |
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| 66 | */ |
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| 67 | typedef struct rtems_bdbuf_swapout_worker |
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| 68 | { |
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| 69 | rtems_chain_node link; /**< The threads sit on a chain when |
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| 70 | * idle. */ |
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| 71 | rtems_id id; /**< The id of the task so we can wake |
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| 72 | * it. */ |
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| 73 | volatile bool enabled; /**< The worked is enabled. */ |
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| 74 | rtems_bdbuf_swapout_transfer transfer; /**< The transfer data for this |
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| 75 | * thread. */ |
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| 76 | } rtems_bdbuf_swapout_worker; |
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| 77 | |
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[3899a537] | 78 | /** |
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[0d15414e] | 79 | * The BD buffer cache. |
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[0ebfac19] | 80 | */ |
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[0d15414e] | 81 | typedef struct rtems_bdbuf_cache |
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| 82 | { |
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| 83 | rtems_id swapout; /**< Swapout task ID */ |
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| 84 | volatile bool swapout_enabled; /**< Swapout is only running if |
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| 85 | * enabled. Set to false to kill the |
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| 86 | * swap out task. It deletes itself. */ |
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| 87 | rtems_chain_control swapout_workers; /**< The work threads for the swapout |
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| 88 | * task. */ |
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| 89 | |
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| 90 | rtems_bdbuf_buffer* bds; /**< Pointer to table of buffer |
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| 91 | * descriptors. */ |
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| 92 | void* buffers; /**< The buffer's memory. */ |
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| 93 | size_t buffer_min_count; /**< Number of minimum size buffers |
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| 94 | * that fit the buffer memory. */ |
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| 95 | size_t max_bds_per_group; /**< The number of BDs of minimum |
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| 96 | * buffer size that fit in a group. */ |
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| 97 | uint32_t flags; /**< Configuration flags. */ |
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| 98 | |
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| 99 | rtems_id lock; /**< The cache lock. It locks all |
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| 100 | * cache data, BD and lists. */ |
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| 101 | rtems_id sync_lock; /**< Sync calls block writes. */ |
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| 102 | volatile bool sync_active; /**< True if a sync is active. */ |
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| 103 | volatile rtems_id sync_requester; /**< The sync requester. */ |
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| 104 | volatile dev_t sync_device; /**< The device to sync and -1 not a |
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| 105 | * device sync. */ |
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| 106 | |
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| 107 | rtems_bdbuf_buffer* tree; /**< Buffer descriptor lookup AVL tree |
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| 108 | * root. There is only one. */ |
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| 109 | rtems_chain_control ready; /**< Free buffers list, read-ahead, or |
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| 110 | * resized group buffers. */ |
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| 111 | rtems_chain_control lru; /**< Least recently used list */ |
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| 112 | rtems_chain_control modified; /**< Modified buffers list */ |
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| 113 | rtems_chain_control sync; /**< Buffers to sync list */ |
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| 114 | |
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| 115 | rtems_id access; /**< Obtain if waiting for a buffer in |
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| 116 | * the ACCESS state. */ |
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| 117 | volatile uint32_t access_waiters; /**< Count of access blockers. */ |
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| 118 | rtems_id transfer; /**< Obtain if waiting for a buffer in |
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| 119 | * the TRANSFER state. */ |
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| 120 | volatile uint32_t transfer_waiters; /**< Count of transfer blockers. */ |
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| 121 | rtems_id waiting; /**< Obtain if waiting for a buffer |
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| 122 | * and the none are available. */ |
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| 123 | volatile uint32_t wait_waiters; /**< Count of waiting blockers. */ |
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| 124 | |
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| 125 | size_t group_count; /**< The number of groups. */ |
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| 126 | rtems_bdbuf_group* groups; /**< The groups. */ |
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| 127 | |
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| 128 | bool initialised; /**< Initialised state. */ |
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| 129 | } rtems_bdbuf_cache; |
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[3899a537] | 130 | |
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| 131 | /** |
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| 132 | * Fatal errors |
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[0ebfac19] | 133 | */ |
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[c21c850e] | 134 | #define RTEMS_BLKDEV_FATAL_ERROR(n) \ |
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| 135 | (((uint32_t)'B' << 24) | ((uint32_t)(n) & (uint32_t)0x00FFFFFF)) |
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[3899a537] | 136 | |
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[945884fe] | 137 | #define RTEMS_BLKDEV_FATAL_BDBUF_CONSISTENCY_1 RTEMS_BLKDEV_FATAL_ERROR(1) |
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| 138 | #define RTEMS_BLKDEV_FATAL_BDBUF_CONSISTENCY_2 RTEMS_BLKDEV_FATAL_ERROR(2) |
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| 139 | #define RTEMS_BLKDEV_FATAL_BDBUF_CONSISTENCY_3 RTEMS_BLKDEV_FATAL_ERROR(3) |
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| 140 | #define RTEMS_BLKDEV_FATAL_BDBUF_CONSISTENCY_4 RTEMS_BLKDEV_FATAL_ERROR(4) |
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| 141 | #define RTEMS_BLKDEV_FATAL_BDBUF_CONSISTENCY_5 RTEMS_BLKDEV_FATAL_ERROR(5) |
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| 142 | #define RTEMS_BLKDEV_FATAL_BDBUF_CONSISTENCY_6 RTEMS_BLKDEV_FATAL_ERROR(6) |
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| 143 | #define RTEMS_BLKDEV_FATAL_BDBUF_CONSISTENCY_7 RTEMS_BLKDEV_FATAL_ERROR(7) |
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| 144 | #define RTEMS_BLKDEV_FATAL_BDBUF_CONSISTENCY_8 RTEMS_BLKDEV_FATAL_ERROR(8) |
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| 145 | #define RTEMS_BLKDEV_FATAL_BDBUF_CONSISTENCY_9 RTEMS_BLKDEV_FATAL_ERROR(9) |
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| 146 | #define RTEMS_BLKDEV_FATAL_BDBUF_SWAPOUT RTEMS_BLKDEV_FATAL_ERROR(10) |
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| 147 | #define RTEMS_BLKDEV_FATAL_BDBUF_SYNC_LOCK RTEMS_BLKDEV_FATAL_ERROR(11) |
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| 148 | #define RTEMS_BLKDEV_FATAL_BDBUF_SYNC_UNLOCK RTEMS_BLKDEV_FATAL_ERROR(12) |
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| 149 | #define RTEMS_BLKDEV_FATAL_BDBUF_CACHE_LOCK RTEMS_BLKDEV_FATAL_ERROR(13) |
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| 150 | #define RTEMS_BLKDEV_FATAL_BDBUF_CACHE_UNLOCK RTEMS_BLKDEV_FATAL_ERROR(14) |
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| 151 | #define RTEMS_BLKDEV_FATAL_BDBUF_CACHE_WAIT_1 RTEMS_BLKDEV_FATAL_ERROR(15) |
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| 152 | #define RTEMS_BLKDEV_FATAL_BDBUF_CACHE_WAIT_2 RTEMS_BLKDEV_FATAL_ERROR(16) |
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| 153 | #define RTEMS_BLKDEV_FATAL_BDBUF_CACHE_WAIT_3 RTEMS_BLKDEV_FATAL_ERROR(17) |
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[eb649786] | 154 | #define RTEMS_BLKDEV_FATAL_BDBUF_CACHE_WAIT_TO RTEMS_BLKDEV_FATAL_ERROR(18) |
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| 155 | #define RTEMS_BLKDEV_FATAL_BDBUF_CACHE_WAKE RTEMS_BLKDEV_FATAL_ERROR(19) |
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| 156 | #define RTEMS_BLKDEV_FATAL_BDBUF_SO_WAKE RTEMS_BLKDEV_FATAL_ERROR(20) |
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| 157 | #define RTEMS_BLKDEV_FATAL_BDBUF_SO_NOMEM RTEMS_BLKDEV_FATAL_ERROR(21) |
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| 158 | #define RTEMS_BLKDEV_FATAL_BDBUF_SO_WK_CREATE RTEMS_BLKDEV_FATAL_ERROR(22) |
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| 159 | #define RTEMS_BLKDEV_FATAL_BDBUF_SO_WK_START RTEMS_BLKDEV_FATAL_ERROR(23) |
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| 160 | #define BLKDEV_FATAL_BDBUF_SWAPOUT_RE RTEMS_BLKDEV_FATAL_ERROR(24) |
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| 161 | #define BLKDEV_FATAL_BDBUF_SWAPOUT_TS RTEMS_BLKDEV_FATAL_ERROR(25) |
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[3899a537] | 162 | |
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[c21c850e] | 163 | /** |
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| 164 | * The events used in this code. These should be system events rather than |
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| 165 | * application events. |
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| 166 | */ |
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[3899a537] | 167 | #define RTEMS_BDBUF_TRANSFER_SYNC RTEMS_EVENT_1 |
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| 168 | #define RTEMS_BDBUF_SWAPOUT_SYNC RTEMS_EVENT_2 |
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| 169 | |
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[c21c850e] | 170 | /** |
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| 171 | * The swap out task size. Should be more than enough for most drivers with |
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| 172 | * tracing turned on. |
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| 173 | */ |
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[3899a537] | 174 | #define SWAPOUT_TASK_STACK_SIZE (8 * 1024) |
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| 175 | |
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| 176 | /** |
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| 177 | * Lock semaphore attributes. This is used for locking type mutexes. |
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[c21c850e] | 178 | * |
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| 179 | * @warning Priority inheritance is on. |
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[3899a537] | 180 | */ |
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[0d15414e] | 181 | #define RTEMS_BDBUF_CACHE_LOCK_ATTRIBS \ |
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[3899a537] | 182 | (RTEMS_PRIORITY | RTEMS_BINARY_SEMAPHORE | \ |
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| 183 | RTEMS_INHERIT_PRIORITY | RTEMS_NO_PRIORITY_CEILING | RTEMS_LOCAL) |
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[048dcd2b] | 184 | |
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[3899a537] | 185 | /** |
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| 186 | * Waiter semaphore attributes. |
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| 187 | * |
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[c21c850e] | 188 | * @warning Do not configure as inherit priority. If a driver is in the driver |
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| 189 | * initialisation table this locked semaphore will have the IDLE task |
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| 190 | * as the holder and a blocking task will raise the priority of the |
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| 191 | * IDLE task which can cause unsual side effects. |
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[3899a537] | 192 | */ |
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[0d15414e] | 193 | #define RTEMS_BDBUF_CACHE_WAITER_ATTRIBS \ |
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[c21c850e] | 194 | (RTEMS_PRIORITY | RTEMS_SIMPLE_BINARY_SEMAPHORE | \ |
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[3899a537] | 195 | RTEMS_NO_INHERIT_PRIORITY | RTEMS_NO_PRIORITY_CEILING | RTEMS_LOCAL) |
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[e51bd96] | 196 | |
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[eb649786] | 197 | /** |
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| 198 | * Waiter timeout. Set to non-zero to find some info on a waiter that is |
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| 199 | * waiting too long. |
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| 200 | */ |
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| 201 | #define RTEMS_BDBUF_WAIT_TIMEOUT RTEMS_NO_TIMEOUT |
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| 202 | #if !defined (RTEMS_BDBUF_WAIT_TIMEOUT) |
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| 203 | #define RTEMS_BDBUF_WAIT_TIMEOUT \ |
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| 204 | (TOD_MICROSECONDS_TO_TICKS (20000000)) |
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| 205 | #endif |
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| 206 | |
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[3899a537] | 207 | /* |
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| 208 | * The swap out task. |
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| 209 | */ |
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| 210 | static rtems_task rtems_bdbuf_swapout_task(rtems_task_argument arg); |
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[048dcd2b] | 211 | |
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[3899a537] | 212 | /** |
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[0d15414e] | 213 | * The Buffer Descriptor cache. |
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[3899a537] | 214 | */ |
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[0d15414e] | 215 | static rtems_bdbuf_cache bdbuf_cache; |
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[e51bd96] | 216 | |
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[eb649786] | 217 | #if RTEMS_BDBUF_TRACE |
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[3899a537] | 218 | /** |
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[eb649786] | 219 | * If true output the trace message. |
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[3899a537] | 220 | */ |
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[4f971343] | 221 | bool rtems_bdbuf_tracer; |
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[eb649786] | 222 | |
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| 223 | /** |
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| 224 | * Return the number of items on the list. |
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| 225 | * |
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| 226 | * @param list The chain control. |
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| 227 | * @return uint32_t The number of items on the list. |
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| 228 | */ |
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| 229 | uint32_t |
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| 230 | rtems_bdbuf_list_count (rtems_chain_control* list) |
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[3899a537] | 231 | { |
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[eb649786] | 232 | rtems_chain_node* node = rtems_chain_first (list); |
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| 233 | uint32_t count = 0; |
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| 234 | while (!rtems_chain_is_tail (list, node)) |
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[3899a537] | 235 | { |
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[eb649786] | 236 | count++; |
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| 237 | node = rtems_chain_next (node); |
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[3899a537] | 238 | } |
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[eb649786] | 239 | return count; |
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| 240 | } |
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| 241 | |
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| 242 | /** |
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| 243 | * Show the usage for the bdbuf cache. |
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| 244 | */ |
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| 245 | void |
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| 246 | rtems_bdbuf_show_usage (void) |
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| 247 | { |
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| 248 | uint32_t group; |
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| 249 | uint32_t total = 0; |
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| 250 | uint32_t val; |
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| 251 | for (group = 0; group < bdbuf_cache.group_count; group++) |
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| 252 | total += bdbuf_cache.groups[group].users; |
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| 253 | printf ("bdbuf:group users=%lu", total); |
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| 254 | val = rtems_bdbuf_list_count (&bdbuf_cache.ready); |
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| 255 | printf (", ready=%lu", val); |
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| 256 | total = val; |
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| 257 | val = rtems_bdbuf_list_count (&bdbuf_cache.lru); |
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| 258 | printf (", lru=%lu", val); |
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| 259 | total += val; |
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| 260 | val = rtems_bdbuf_list_count (&bdbuf_cache.modified); |
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| 261 | printf (", mod=%lu", val); |
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| 262 | total += val; |
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| 263 | val = rtems_bdbuf_list_count (&bdbuf_cache.sync); |
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| 264 | printf (", sync=%lu", val); |
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| 265 | total += val; |
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| 266 | printf (", total=%lu\n", total); |
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[3899a537] | 267 | } |
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[eb649786] | 268 | |
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| 269 | /** |
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| 270 | * Show the users for a group of a bd. |
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| 271 | * |
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| 272 | * @param where A label to show the context of output. |
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| 273 | * @param bd The bd to show the users of. |
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| 274 | */ |
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| 275 | void |
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| 276 | rtems_bdbuf_show_users (const char* where, rtems_bdbuf_buffer* bd) |
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| 277 | { |
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| 278 | const char* states[] = |
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| 279 | { "EM", "RA", "CH", "AC", "MD", "AM", "SY", "TR" }; |
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| 280 | printf ("bdbuf:users: %15s: [%ld (%s)] %ld:%ld = %lu %s\n", |
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| 281 | where, |
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| 282 | bd->block, states[bd->state], |
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| 283 | bd->group - bdbuf_cache.groups, |
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| 284 | bd - bdbuf_cache.bds, |
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| 285 | bd->group->users, |
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| 286 | bd->group->users > 8 ? "<<<<<<<" : ""); |
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| 287 | } |
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| 288 | #else |
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| 289 | #define rtems_bdbuf_tracer (0) |
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| 290 | #define rtems_bdbuf_show_usage() |
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| 291 | #define rtems_bdbuf_show_users(_w, _b) |
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[e51bd96] | 292 | #endif |
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| 293 | |
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[3899a537] | 294 | /** |
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| 295 | * The default maximum height of 32 allows for AVL trees having between |
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| 296 | * 5,704,880 and 4,294,967,295 nodes, depending on order of insertion. You may |
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| 297 | * change this compile-time constant as you wish. |
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| 298 | */ |
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| 299 | #ifndef RTEMS_BDBUF_AVL_MAX_HEIGHT |
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| 300 | #define RTEMS_BDBUF_AVL_MAX_HEIGHT (32) |
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[e51bd96] | 301 | #endif |
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| 302 | |
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[3899a537] | 303 | /** |
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| 304 | * Searches for the node with specified dev/block. |
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[e51bd96] | 305 | * |
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[3899a537] | 306 | * @param root pointer to the root node of the AVL-Tree |
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| 307 | * @param dev device search key |
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| 308 | * @param block block search key |
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| 309 | * @retval NULL node with the specified dev/block is not found |
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| 310 | * @return pointer to the node with specified dev/block |
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[e51bd96] | 311 | */ |
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[3899a537] | 312 | static rtems_bdbuf_buffer * |
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| 313 | rtems_bdbuf_avl_search (rtems_bdbuf_buffer** root, |
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| 314 | dev_t dev, |
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| 315 | rtems_blkdev_bnum block) |
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[e51bd96] | 316 | { |
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[3899a537] | 317 | rtems_bdbuf_buffer* p = *root; |
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[df6348bb] | 318 | |
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[3899a537] | 319 | while ((p != NULL) && ((p->dev != dev) || (p->block != block))) |
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| 320 | { |
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| 321 | if ((p->dev < dev) || ((p->dev == dev) && (p->block < block))) |
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[e51bd96] | 322 | { |
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[3899a537] | 323 | p = p->avl.right; |
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| 324 | } |
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| 325 | else |
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| 326 | { |
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| 327 | p = p->avl.left; |
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[e51bd96] | 328 | } |
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[3899a537] | 329 | } |
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[048dcd2b] | 330 | |
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[3899a537] | 331 | return p; |
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[e51bd96] | 332 | } |
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| 333 | |
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[3899a537] | 334 | /** |
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| 335 | * Inserts the specified node to the AVl-Tree. |
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[e51bd96] | 336 | * |
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[3899a537] | 337 | * @param root pointer to the root node of the AVL-Tree |
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| 338 | * @param node Pointer to the node to add. |
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| 339 | * @retval 0 The node added successfully |
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| 340 | * @retval -1 An error occured |
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[e51bd96] | 341 | */ |
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| 342 | static int |
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[3899a537] | 343 | rtems_bdbuf_avl_insert(rtems_bdbuf_buffer** root, |
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| 344 | rtems_bdbuf_buffer* node) |
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[e51bd96] | 345 | { |
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[3899a537] | 346 | dev_t dev = node->dev; |
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| 347 | rtems_blkdev_bnum block = node->block; |
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| 348 | |
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| 349 | rtems_bdbuf_buffer* p = *root; |
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| 350 | rtems_bdbuf_buffer* q; |
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| 351 | rtems_bdbuf_buffer* p1; |
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| 352 | rtems_bdbuf_buffer* p2; |
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| 353 | rtems_bdbuf_buffer* buf_stack[RTEMS_BDBUF_AVL_MAX_HEIGHT]; |
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| 354 | rtems_bdbuf_buffer** buf_prev = buf_stack; |
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| 355 | |
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[4f971343] | 356 | bool modified = false; |
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[3899a537] | 357 | |
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| 358 | if (p == NULL) |
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| 359 | { |
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| 360 | *root = node; |
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| 361 | node->avl.left = NULL; |
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| 362 | node->avl.right = NULL; |
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| 363 | node->avl.bal = 0; |
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| 364 | return 0; |
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| 365 | } |
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[e51bd96] | 366 | |
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[3899a537] | 367 | while (p != NULL) |
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| 368 | { |
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| 369 | *buf_prev++ = p; |
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[e51bd96] | 370 | |
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[3899a537] | 371 | if ((p->dev < dev) || ((p->dev == dev) && (p->block < block))) |
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[e51bd96] | 372 | { |
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[3899a537] | 373 | p->avl.cache = 1; |
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| 374 | q = p->avl.right; |
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| 375 | if (q == NULL) |
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| 376 | { |
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| 377 | q = node; |
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| 378 | p->avl.right = q = node; |
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| 379 | break; |
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| 380 | } |
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[e51bd96] | 381 | } |
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[3899a537] | 382 | else if ((p->dev != dev) || (p->block != block)) |
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[e51bd96] | 383 | { |
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[3899a537] | 384 | p->avl.cache = -1; |
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| 385 | q = p->avl.left; |
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| 386 | if (q == NULL) |
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| 387 | { |
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| 388 | q = node; |
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| 389 | p->avl.left = q; |
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| 390 | break; |
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| 391 | } |
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| 392 | } |
---|
| 393 | else |
---|
| 394 | { |
---|
| 395 | return -1; |
---|
[e51bd96] | 396 | } |
---|
| 397 | |
---|
[3899a537] | 398 | p = q; |
---|
| 399 | } |
---|
[eb649786] | 400 | |
---|
[3899a537] | 401 | q->avl.left = q->avl.right = NULL; |
---|
| 402 | q->avl.bal = 0; |
---|
[4f971343] | 403 | modified = true; |
---|
[3899a537] | 404 | buf_prev--; |
---|
[e51bd96] | 405 | |
---|
[3899a537] | 406 | while (modified) |
---|
| 407 | { |
---|
| 408 | if (p->avl.cache == -1) |
---|
| 409 | { |
---|
| 410 | switch (p->avl.bal) |
---|
| 411 | { |
---|
| 412 | case 1: |
---|
| 413 | p->avl.bal = 0; |
---|
[4f971343] | 414 | modified = false; |
---|
[3899a537] | 415 | break; |
---|
| 416 | |
---|
| 417 | case 0: |
---|
| 418 | p->avl.bal = -1; |
---|
| 419 | break; |
---|
| 420 | |
---|
| 421 | case -1: |
---|
| 422 | p1 = p->avl.left; |
---|
| 423 | if (p1->avl.bal == -1) /* simple LL-turn */ |
---|
| 424 | { |
---|
| 425 | p->avl.left = p1->avl.right; |
---|
| 426 | p1->avl.right = p; |
---|
| 427 | p->avl.bal = 0; |
---|
| 428 | p = p1; |
---|
| 429 | } |
---|
| 430 | else /* double LR-turn */ |
---|
| 431 | { |
---|
| 432 | p2 = p1->avl.right; |
---|
| 433 | p1->avl.right = p2->avl.left; |
---|
| 434 | p2->avl.left = p1; |
---|
| 435 | p->avl.left = p2->avl.right; |
---|
| 436 | p2->avl.right = p; |
---|
| 437 | if (p2->avl.bal == -1) p->avl.bal = +1; else p->avl.bal = 0; |
---|
| 438 | if (p2->avl.bal == +1) p1->avl.bal = -1; else p1->avl.bal = 0; |
---|
| 439 | p = p2; |
---|
| 440 | } |
---|
| 441 | p->avl.bal = 0; |
---|
[4f971343] | 442 | modified = false; |
---|
[3899a537] | 443 | break; |
---|
| 444 | |
---|
| 445 | default: |
---|
| 446 | break; |
---|
| 447 | } |
---|
| 448 | } |
---|
| 449 | else |
---|
| 450 | { |
---|
| 451 | switch (p->avl.bal) |
---|
| 452 | { |
---|
| 453 | case -1: |
---|
| 454 | p->avl.bal = 0; |
---|
[4f971343] | 455 | modified = false; |
---|
[3899a537] | 456 | break; |
---|
| 457 | |
---|
| 458 | case 0: |
---|
| 459 | p->avl.bal = 1; |
---|
| 460 | break; |
---|
| 461 | |
---|
| 462 | case 1: |
---|
| 463 | p1 = p->avl.right; |
---|
| 464 | if (p1->avl.bal == 1) /* simple RR-turn */ |
---|
| 465 | { |
---|
| 466 | p->avl.right = p1->avl.left; |
---|
| 467 | p1->avl.left = p; |
---|
| 468 | p->avl.bal = 0; |
---|
| 469 | p = p1; |
---|
| 470 | } |
---|
| 471 | else /* double RL-turn */ |
---|
| 472 | { |
---|
| 473 | p2 = p1->avl.left; |
---|
| 474 | p1->avl.left = p2->avl.right; |
---|
| 475 | p2->avl.right = p1; |
---|
| 476 | p->avl.right = p2->avl.left; |
---|
| 477 | p2->avl.left = p; |
---|
| 478 | if (p2->avl.bal == +1) p->avl.bal = -1; else p->avl.bal = 0; |
---|
| 479 | if (p2->avl.bal == -1) p1->avl.bal = +1; else p1->avl.bal = 0; |
---|
| 480 | p = p2; |
---|
| 481 | } |
---|
| 482 | p->avl.bal = 0; |
---|
[4f971343] | 483 | modified = false; |
---|
[3899a537] | 484 | break; |
---|
| 485 | |
---|
| 486 | default: |
---|
| 487 | break; |
---|
| 488 | } |
---|
| 489 | } |
---|
| 490 | q = p; |
---|
| 491 | if (buf_prev > buf_stack) |
---|
| 492 | { |
---|
| 493 | p = *--buf_prev; |
---|
| 494 | |
---|
| 495 | if (p->avl.cache == -1) |
---|
| 496 | { |
---|
| 497 | p->avl.left = q; |
---|
| 498 | } |
---|
| 499 | else |
---|
| 500 | { |
---|
| 501 | p->avl.right = q; |
---|
| 502 | } |
---|
| 503 | } |
---|
| 504 | else |
---|
| 505 | { |
---|
| 506 | *root = p; |
---|
| 507 | break; |
---|
| 508 | } |
---|
| 509 | }; |
---|
[e51bd96] | 510 | |
---|
[3899a537] | 511 | return 0; |
---|
[e51bd96] | 512 | } |
---|
| 513 | |
---|
| 514 | |
---|
[3899a537] | 515 | /** |
---|
| 516 | * Removes the node from the tree. |
---|
[e51bd96] | 517 | * |
---|
[57aa979] | 518 | * @param root Pointer to pointer to the root node |
---|
[3899a537] | 519 | * @param node Pointer to the node to remove |
---|
| 520 | * @retval 0 Item removed |
---|
| 521 | * @retval -1 No such item found |
---|
[e51bd96] | 522 | */ |
---|
| 523 | static int |
---|
[3899a537] | 524 | rtems_bdbuf_avl_remove(rtems_bdbuf_buffer** root, |
---|
| 525 | const rtems_bdbuf_buffer* node) |
---|
[e51bd96] | 526 | { |
---|
[3899a537] | 527 | dev_t dev = node->dev; |
---|
| 528 | rtems_blkdev_bnum block = node->block; |
---|
[e51bd96] | 529 | |
---|
[3899a537] | 530 | rtems_bdbuf_buffer* p = *root; |
---|
| 531 | rtems_bdbuf_buffer* q; |
---|
| 532 | rtems_bdbuf_buffer* r; |
---|
| 533 | rtems_bdbuf_buffer* s; |
---|
| 534 | rtems_bdbuf_buffer* p1; |
---|
| 535 | rtems_bdbuf_buffer* p2; |
---|
| 536 | rtems_bdbuf_buffer* buf_stack[RTEMS_BDBUF_AVL_MAX_HEIGHT]; |
---|
| 537 | rtems_bdbuf_buffer** buf_prev = buf_stack; |
---|
[e51bd96] | 538 | |
---|
[4f971343] | 539 | bool modified = false; |
---|
[e51bd96] | 540 | |
---|
[3899a537] | 541 | memset (buf_stack, 0, sizeof(buf_stack)); |
---|
[e51bd96] | 542 | |
---|
[3899a537] | 543 | while (p != NULL) |
---|
| 544 | { |
---|
| 545 | *buf_prev++ = p; |
---|
[e51bd96] | 546 | |
---|
[3899a537] | 547 | if ((p->dev < dev) || ((p->dev == dev) && (p->block < block))) |
---|
| 548 | { |
---|
| 549 | p->avl.cache = 1; |
---|
| 550 | p = p->avl.right; |
---|
| 551 | } |
---|
| 552 | else if ((p->dev != dev) || (p->block != block)) |
---|
| 553 | { |
---|
| 554 | p->avl.cache = -1; |
---|
| 555 | p = p->avl.left; |
---|
[df6348bb] | 556 | } |
---|
[3899a537] | 557 | else |
---|
| 558 | { |
---|
| 559 | /* node found */ |
---|
| 560 | break; |
---|
| 561 | } |
---|
| 562 | } |
---|
| 563 | |
---|
| 564 | if (p == NULL) |
---|
| 565 | { |
---|
| 566 | /* there is no such node */ |
---|
| 567 | return -1; |
---|
| 568 | } |
---|
[048dcd2b] | 569 | |
---|
[3899a537] | 570 | q = p; |
---|
| 571 | |
---|
| 572 | buf_prev--; |
---|
| 573 | if (buf_prev > buf_stack) |
---|
| 574 | { |
---|
| 575 | p = *(buf_prev - 1); |
---|
| 576 | } |
---|
| 577 | else |
---|
| 578 | { |
---|
| 579 | p = NULL; |
---|
| 580 | } |
---|
| 581 | |
---|
| 582 | /* at this moment q - is a node to delete, p is q's parent */ |
---|
| 583 | if (q->avl.right == NULL) |
---|
| 584 | { |
---|
| 585 | r = q->avl.left; |
---|
| 586 | if (r != NULL) |
---|
[df6348bb] | 587 | { |
---|
[3899a537] | 588 | r->avl.bal = 0; |
---|
[e51bd96] | 589 | } |
---|
[3899a537] | 590 | q = r; |
---|
| 591 | } |
---|
| 592 | else |
---|
| 593 | { |
---|
| 594 | rtems_bdbuf_buffer **t; |
---|
[e51bd96] | 595 | |
---|
[3899a537] | 596 | r = q->avl.right; |
---|
[df6348bb] | 597 | |
---|
[3899a537] | 598 | if (r->avl.left == NULL) |
---|
[e51bd96] | 599 | { |
---|
[3899a537] | 600 | r->avl.left = q->avl.left; |
---|
| 601 | r->avl.bal = q->avl.bal; |
---|
| 602 | r->avl.cache = 1; |
---|
| 603 | *buf_prev++ = q = r; |
---|
[e51bd96] | 604 | } |
---|
| 605 | else |
---|
| 606 | { |
---|
[3899a537] | 607 | t = buf_prev++; |
---|
| 608 | s = r; |
---|
| 609 | |
---|
| 610 | while (s->avl.left != NULL) |
---|
| 611 | { |
---|
| 612 | *buf_prev++ = r = s; |
---|
| 613 | s = r->avl.left; |
---|
| 614 | r->avl.cache = -1; |
---|
| 615 | } |
---|
| 616 | |
---|
| 617 | s->avl.left = q->avl.left; |
---|
| 618 | r->avl.left = s->avl.right; |
---|
| 619 | s->avl.right = q->avl.right; |
---|
| 620 | s->avl.bal = q->avl.bal; |
---|
| 621 | s->avl.cache = 1; |
---|
| 622 | |
---|
| 623 | *t = q = s; |
---|
[e51bd96] | 624 | } |
---|
[3899a537] | 625 | } |
---|
[df6348bb] | 626 | |
---|
[3899a537] | 627 | if (p != NULL) |
---|
| 628 | { |
---|
| 629 | if (p->avl.cache == -1) |
---|
[e51bd96] | 630 | { |
---|
[3899a537] | 631 | p->avl.left = q; |
---|
[e51bd96] | 632 | } |
---|
| 633 | else |
---|
| 634 | { |
---|
[3899a537] | 635 | p->avl.right = q; |
---|
[e51bd96] | 636 | } |
---|
[3899a537] | 637 | } |
---|
| 638 | else |
---|
| 639 | { |
---|
| 640 | *root = q; |
---|
| 641 | } |
---|
[e51bd96] | 642 | |
---|
[4f971343] | 643 | modified = true; |
---|
[3899a537] | 644 | |
---|
| 645 | while (modified) |
---|
| 646 | { |
---|
| 647 | if (buf_prev > buf_stack) |
---|
[e51bd96] | 648 | { |
---|
[3899a537] | 649 | p = *--buf_prev; |
---|
[df6348bb] | 650 | } |
---|
| 651 | else |
---|
| 652 | { |
---|
[3899a537] | 653 | break; |
---|
[df6348bb] | 654 | } |
---|
[e51bd96] | 655 | |
---|
[3899a537] | 656 | if (p->avl.cache == -1) |
---|
[df6348bb] | 657 | { |
---|
[3899a537] | 658 | /* rebalance left branch */ |
---|
| 659 | switch (p->avl.bal) |
---|
| 660 | { |
---|
| 661 | case -1: |
---|
| 662 | p->avl.bal = 0; |
---|
| 663 | break; |
---|
| 664 | case 0: |
---|
| 665 | p->avl.bal = 1; |
---|
[4f971343] | 666 | modified = false; |
---|
[3899a537] | 667 | break; |
---|
| 668 | |
---|
| 669 | case +1: |
---|
| 670 | p1 = p->avl.right; |
---|
| 671 | |
---|
| 672 | if (p1->avl.bal >= 0) /* simple RR-turn */ |
---|
| 673 | { |
---|
| 674 | p->avl.right = p1->avl.left; |
---|
| 675 | p1->avl.left = p; |
---|
| 676 | |
---|
| 677 | if (p1->avl.bal == 0) |
---|
[e51bd96] | 678 | { |
---|
[3899a537] | 679 | p1->avl.bal = -1; |
---|
[4f971343] | 680 | modified = false; |
---|
[df6348bb] | 681 | } |
---|
[3899a537] | 682 | else |
---|
[e51bd96] | 683 | { |
---|
[3899a537] | 684 | p->avl.bal = 0; |
---|
| 685 | p1->avl.bal = 0; |
---|
[df6348bb] | 686 | } |
---|
[3899a537] | 687 | p = p1; |
---|
| 688 | } |
---|
| 689 | else /* double RL-turn */ |
---|
| 690 | { |
---|
| 691 | p2 = p1->avl.left; |
---|
| 692 | |
---|
| 693 | p1->avl.left = p2->avl.right; |
---|
| 694 | p2->avl.right = p1; |
---|
| 695 | p->avl.right = p2->avl.left; |
---|
| 696 | p2->avl.left = p; |
---|
| 697 | |
---|
| 698 | if (p2->avl.bal == +1) p->avl.bal = -1; else p->avl.bal = 0; |
---|
| 699 | if (p2->avl.bal == -1) p1->avl.bal = 1; else p1->avl.bal = 0; |
---|
| 700 | |
---|
| 701 | p = p2; |
---|
| 702 | p2->avl.bal = 0; |
---|
| 703 | } |
---|
| 704 | break; |
---|
| 705 | |
---|
| 706 | default: |
---|
| 707 | break; |
---|
| 708 | } |
---|
| 709 | } |
---|
| 710 | else |
---|
| 711 | { |
---|
| 712 | /* rebalance right branch */ |
---|
| 713 | switch (p->avl.bal) |
---|
| 714 | { |
---|
| 715 | case +1: |
---|
| 716 | p->avl.bal = 0; |
---|
| 717 | break; |
---|
| 718 | |
---|
| 719 | case 0: |
---|
| 720 | p->avl.bal = -1; |
---|
[4f971343] | 721 | modified = false; |
---|
[3899a537] | 722 | break; |
---|
| 723 | |
---|
| 724 | case -1: |
---|
| 725 | p1 = p->avl.left; |
---|
| 726 | |
---|
| 727 | if (p1->avl.bal <= 0) /* simple LL-turn */ |
---|
| 728 | { |
---|
| 729 | p->avl.left = p1->avl.right; |
---|
| 730 | p1->avl.right = p; |
---|
| 731 | if (p1->avl.bal == 0) |
---|
[df6348bb] | 732 | { |
---|
[3899a537] | 733 | p1->avl.bal = 1; |
---|
[4f971343] | 734 | modified = false; |
---|
[df6348bb] | 735 | } |
---|
| 736 | else |
---|
| 737 | { |
---|
[3899a537] | 738 | p->avl.bal = 0; |
---|
| 739 | p1->avl.bal = 0; |
---|
[df6348bb] | 740 | } |
---|
[3899a537] | 741 | p = p1; |
---|
| 742 | } |
---|
| 743 | else /* double LR-turn */ |
---|
| 744 | { |
---|
| 745 | p2 = p1->avl.right; |
---|
| 746 | |
---|
| 747 | p1->avl.right = p2->avl.left; |
---|
| 748 | p2->avl.left = p1; |
---|
| 749 | p->avl.left = p2->avl.right; |
---|
| 750 | p2->avl.right = p; |
---|
| 751 | |
---|
| 752 | if (p2->avl.bal == -1) p->avl.bal = 1; else p->avl.bal = 0; |
---|
| 753 | if (p2->avl.bal == +1) p1->avl.bal = -1; else p1->avl.bal = 0; |
---|
| 754 | |
---|
| 755 | p = p2; |
---|
| 756 | p2->avl.bal = 0; |
---|
| 757 | } |
---|
| 758 | break; |
---|
| 759 | |
---|
| 760 | default: |
---|
| 761 | break; |
---|
| 762 | } |
---|
| 763 | } |
---|
[df6348bb] | 764 | |
---|
[3899a537] | 765 | if (buf_prev > buf_stack) |
---|
| 766 | { |
---|
| 767 | q = *(buf_prev - 1); |
---|
| 768 | |
---|
| 769 | if (q->avl.cache == -1) |
---|
| 770 | { |
---|
| 771 | q->avl.left = p; |
---|
| 772 | } |
---|
| 773 | else |
---|
| 774 | { |
---|
| 775 | q->avl.right = p; |
---|
| 776 | } |
---|
| 777 | } |
---|
| 778 | else |
---|
| 779 | { |
---|
| 780 | *root = p; |
---|
| 781 | break; |
---|
[df6348bb] | 782 | } |
---|
[048dcd2b] | 783 | |
---|
[3899a537] | 784 | } |
---|
| 785 | |
---|
| 786 | return 0; |
---|
| 787 | } |
---|
| 788 | |
---|
[eb649786] | 789 | /** |
---|
| 790 | * Change the block number for the block size to the block number for the media |
---|
| 791 | * block size. We have to use 64bit maths. There is no short cut here. |
---|
| 792 | * |
---|
| 793 | * @param block The logical block number in the block size terms. |
---|
| 794 | * @param block_size The block size. |
---|
| 795 | * @param media_block_size The block size of the media. |
---|
| 796 | * @return rtems_blkdev_bnum The media block number. |
---|
| 797 | */ |
---|
| 798 | static rtems_blkdev_bnum |
---|
| 799 | rtems_bdbuf_media_block (rtems_blkdev_bnum block, |
---|
| 800 | size_t block_size, |
---|
| 801 | size_t media_block_size) |
---|
| 802 | { |
---|
| 803 | return (((uint64_t) block) * block_size) / media_block_size; |
---|
| 804 | } |
---|
| 805 | |
---|
[3899a537] | 806 | /** |
---|
[0d15414e] | 807 | * Lock the mutex. A single task can nest calls. |
---|
[3899a537] | 808 | * |
---|
[0d15414e] | 809 | * @param lock The mutex to lock. |
---|
| 810 | * @param fatal_error_code The error code if the call fails. |
---|
[3899a537] | 811 | */ |
---|
[0d15414e] | 812 | static void |
---|
| 813 | rtems_bdbuf_lock (rtems_id lock, uint32_t fatal_error_code) |
---|
[3899a537] | 814 | { |
---|
[0d15414e] | 815 | rtems_status_code sc = rtems_semaphore_obtain (lock, |
---|
| 816 | RTEMS_WAIT, |
---|
| 817 | RTEMS_NO_TIMEOUT); |
---|
| 818 | if (sc != RTEMS_SUCCESSFUL) |
---|
| 819 | rtems_fatal_error_occurred (fatal_error_code); |
---|
[3899a537] | 820 | } |
---|
| 821 | |
---|
| 822 | /** |
---|
[0d15414e] | 823 | * Unlock the mutex. |
---|
[3899a537] | 824 | * |
---|
[0d15414e] | 825 | * @param lock The mutex to unlock. |
---|
| 826 | * @param fatal_error_code The error code if the call fails. |
---|
[3899a537] | 827 | */ |
---|
| 828 | static void |
---|
[0d15414e] | 829 | rtems_bdbuf_unlock (rtems_id lock, uint32_t fatal_error_code) |
---|
[3899a537] | 830 | { |
---|
[0d15414e] | 831 | rtems_status_code sc = rtems_semaphore_release (lock); |
---|
[3899a537] | 832 | if (sc != RTEMS_SUCCESSFUL) |
---|
[0d15414e] | 833 | rtems_fatal_error_occurred (fatal_error_code); |
---|
[3899a537] | 834 | } |
---|
| 835 | |
---|
| 836 | /** |
---|
[0d15414e] | 837 | * Lock the cache. A single task can nest calls. |
---|
[3899a537] | 838 | */ |
---|
| 839 | static void |
---|
[0d15414e] | 840 | rtems_bdbuf_lock_cache (void) |
---|
[3899a537] | 841 | { |
---|
[0d15414e] | 842 | rtems_bdbuf_lock (bdbuf_cache.lock, RTEMS_BLKDEV_FATAL_BDBUF_CACHE_LOCK); |
---|
[3899a537] | 843 | } |
---|
| 844 | |
---|
| 845 | /** |
---|
[0d15414e] | 846 | * Unlock the cache. |
---|
[3899a537] | 847 | */ |
---|
| 848 | static void |
---|
[0d15414e] | 849 | rtems_bdbuf_unlock_cache (void) |
---|
[3899a537] | 850 | { |
---|
[0d15414e] | 851 | rtems_bdbuf_unlock (bdbuf_cache.lock, RTEMS_BLKDEV_FATAL_BDBUF_CACHE_UNLOCK); |
---|
[3899a537] | 852 | } |
---|
| 853 | |
---|
| 854 | /** |
---|
[0d15414e] | 855 | * Lock the cache's sync. A single task can nest calls. |
---|
[3899a537] | 856 | */ |
---|
| 857 | static void |
---|
[0d15414e] | 858 | rtems_bdbuf_lock_sync (void) |
---|
[3899a537] | 859 | { |
---|
[0d15414e] | 860 | rtems_bdbuf_lock (bdbuf_cache.sync_lock, RTEMS_BLKDEV_FATAL_BDBUF_SYNC_LOCK); |
---|
| 861 | } |
---|
| 862 | |
---|
| 863 | /** |
---|
| 864 | * Unlock the cache's sync lock. Any blocked writers are woken. |
---|
| 865 | */ |
---|
| 866 | static void |
---|
| 867 | rtems_bdbuf_unlock_sync (void) |
---|
| 868 | { |
---|
| 869 | rtems_bdbuf_unlock (bdbuf_cache.sync_lock, |
---|
| 870 | RTEMS_BLKDEV_FATAL_BDBUF_SYNC_UNLOCK); |
---|
[3899a537] | 871 | } |
---|
| 872 | |
---|
| 873 | /** |
---|
[c21c850e] | 874 | * Wait until woken. Semaphores are used so a number of tasks can wait and can |
---|
| 875 | * be woken at once. Task events would require we maintain a list of tasks to |
---|
| 876 | * be woken and this would require storgage and we do not know the number of |
---|
| 877 | * tasks that could be waiting. |
---|
[3899a537] | 878 | * |
---|
[0d15414e] | 879 | * While we have the cache locked we can try and claim the semaphore and |
---|
| 880 | * therefore know when we release the lock to the cache we will block until the |
---|
[3899a537] | 881 | * semaphore is released. This may even happen before we get to block. |
---|
| 882 | * |
---|
| 883 | * A counter is used to save the release call when no one is waiting. |
---|
| 884 | * |
---|
[0d15414e] | 885 | * The function assumes the cache is locked on entry and it will be locked on |
---|
[c21c850e] | 886 | * exit. |
---|
[3899a537] | 887 | * |
---|
| 888 | * @param sema The semaphore to block on and wait. |
---|
| 889 | * @param waiters The wait counter for this semaphore. |
---|
| 890 | */ |
---|
| 891 | static void |
---|
[0d15414e] | 892 | rtems_bdbuf_wait (rtems_id* sema, volatile uint32_t* waiters) |
---|
[3899a537] | 893 | { |
---|
| 894 | rtems_status_code sc; |
---|
| 895 | rtems_mode prev_mode; |
---|
| 896 | |
---|
| 897 | /* |
---|
| 898 | * Indicate we are waiting. |
---|
| 899 | */ |
---|
| 900 | *waiters += 1; |
---|
| 901 | |
---|
| 902 | /* |
---|
[0d15414e] | 903 | * Disable preemption then unlock the cache and block. There is no POSIX |
---|
| 904 | * condition variable in the core API so this is a work around. |
---|
[3899a537] | 905 | * |
---|
[0d15414e] | 906 | * The issue is a task could preempt after the cache is unlocked because it is |
---|
| 907 | * blocking or just hits that window, and before this task has blocked on the |
---|
| 908 | * semaphore. If the preempting task flushes the queue this task will not see |
---|
| 909 | * the flush and may block for ever or until another transaction flushes this |
---|
[3899a537] | 910 | * semaphore. |
---|
| 911 | */ |
---|
| 912 | sc = rtems_task_mode (RTEMS_NO_PREEMPT, RTEMS_PREEMPT_MASK, &prev_mode); |
---|
| 913 | |
---|
| 914 | if (sc != RTEMS_SUCCESSFUL) |
---|
[0d15414e] | 915 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_CACHE_WAIT_1); |
---|
[3899a537] | 916 | |
---|
| 917 | /* |
---|
[0d15414e] | 918 | * Unlock the cache, wait, and lock the cache when we return. |
---|
[3899a537] | 919 | */ |
---|
[0d15414e] | 920 | rtems_bdbuf_unlock_cache (); |
---|
[3899a537] | 921 | |
---|
[eb649786] | 922 | sc = rtems_semaphore_obtain (*sema, RTEMS_WAIT, RTEMS_BDBUF_WAIT_TIMEOUT); |
---|
| 923 | |
---|
| 924 | if (sc == RTEMS_TIMEOUT) |
---|
| 925 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_CACHE_WAIT_TO); |
---|
[3899a537] | 926 | |
---|
| 927 | if (sc != RTEMS_UNSATISFIED) |
---|
[0d15414e] | 928 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_CACHE_WAIT_2); |
---|
[3899a537] | 929 | |
---|
[0d15414e] | 930 | rtems_bdbuf_lock_cache (); |
---|
[3899a537] | 931 | |
---|
| 932 | sc = rtems_task_mode (prev_mode, RTEMS_ALL_MODE_MASKS, &prev_mode); |
---|
| 933 | |
---|
| 934 | if (sc != RTEMS_SUCCESSFUL) |
---|
[0d15414e] | 935 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_CACHE_WAIT_3); |
---|
[3899a537] | 936 | |
---|
| 937 | *waiters -= 1; |
---|
| 938 | } |
---|
| 939 | |
---|
| 940 | /** |
---|
| 941 | * Wake a blocked resource. The resource has a counter that lets us know if |
---|
| 942 | * there are any waiters. |
---|
| 943 | * |
---|
| 944 | * @param sema The semaphore to release. |
---|
| 945 | * @param waiters The wait counter for this semaphore. |
---|
| 946 | */ |
---|
| 947 | static void |
---|
| 948 | rtems_bdbuf_wake (rtems_id sema, volatile uint32_t* waiters) |
---|
| 949 | { |
---|
| 950 | if (*waiters) |
---|
| 951 | { |
---|
| 952 | rtems_status_code sc; |
---|
| 953 | |
---|
| 954 | sc = rtems_semaphore_flush (sema); |
---|
| 955 | |
---|
| 956 | if (sc != RTEMS_SUCCESSFUL) |
---|
[0d15414e] | 957 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_CACHE_WAKE); |
---|
[3899a537] | 958 | } |
---|
| 959 | } |
---|
| 960 | |
---|
| 961 | /** |
---|
| 962 | * Add a buffer descriptor to the modified list. This modified list is treated |
---|
[0d15414e] | 963 | * a litte differently to the other lists. To access it you must have the cache |
---|
[c21c850e] | 964 | * locked and this is assumed to be the case on entry to this call. |
---|
| 965 | * |
---|
[0d15414e] | 966 | * If the cache has a device being sync'ed and the bd is for that device the |
---|
[c21c850e] | 967 | * call must block and wait until the sync is over before adding the bd to the |
---|
| 968 | * modified list. Once a sync happens for a device no bd's can be added the |
---|
| 969 | * modified list. The disk image is forced to be snapshot at that moment in |
---|
| 970 | * time. |
---|
| 971 | * |
---|
[945884fe] | 972 | * @note Do not lower the group user count as the modified list is a user of |
---|
| 973 | * the buffer. |
---|
[3899a537] | 974 | * |
---|
[0d15414e] | 975 | * @param bd The bd to queue to the cache's modified list. |
---|
[3899a537] | 976 | */ |
---|
| 977 | static void |
---|
[0d15414e] | 978 | rtems_bdbuf_append_modified (rtems_bdbuf_buffer* bd) |
---|
[3899a537] | 979 | { |
---|
| 980 | /* |
---|
[0d15414e] | 981 | * If the cache has a device being sync'ed check if this bd is for that |
---|
| 982 | * device. If it is unlock the cache and block on the sync lock. Once we have |
---|
| 983 | * the sync lock release it. |
---|
[3899a537] | 984 | */ |
---|
[0d15414e] | 985 | if (bdbuf_cache.sync_active && (bdbuf_cache.sync_device == bd->dev)) |
---|
[3899a537] | 986 | { |
---|
[0d15414e] | 987 | rtems_bdbuf_unlock_cache (); |
---|
| 988 | /* Wait for the sync lock */ |
---|
| 989 | rtems_bdbuf_lock_sync (); |
---|
| 990 | rtems_bdbuf_unlock_sync (); |
---|
| 991 | rtems_bdbuf_lock_cache (); |
---|
[3899a537] | 992 | } |
---|
| 993 | |
---|
| 994 | bd->state = RTEMS_BDBUF_STATE_MODIFIED; |
---|
| 995 | |
---|
[0d15414e] | 996 | rtems_chain_append (&bdbuf_cache.modified, &bd->link); |
---|
[3899a537] | 997 | } |
---|
| 998 | |
---|
[c21c850e] | 999 | /** |
---|
| 1000 | * Wait the swapper task. |
---|
| 1001 | */ |
---|
[3899a537] | 1002 | static void |
---|
[a5fb40cf] | 1003 | rtems_bdbuf_wake_swapper (void) |
---|
[3899a537] | 1004 | { |
---|
[0d15414e] | 1005 | rtems_status_code sc = rtems_event_send (bdbuf_cache.swapout, |
---|
[3899a537] | 1006 | RTEMS_BDBUF_SWAPOUT_SYNC); |
---|
| 1007 | if (sc != RTEMS_SUCCESSFUL) |
---|
| 1008 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_SO_WAKE); |
---|
[e51bd96] | 1009 | } |
---|
| 1010 | |
---|
[c21c850e] | 1011 | /** |
---|
[0d15414e] | 1012 | * Compute the number of BDs per group for a given buffer size. |
---|
[e51bd96] | 1013 | * |
---|
[0d15414e] | 1014 | * @param size The buffer size. It can be any size and we scale up. |
---|
| 1015 | */ |
---|
| 1016 | static size_t |
---|
| 1017 | rtems_bdbuf_bds_per_group (size_t size) |
---|
| 1018 | { |
---|
| 1019 | size_t bufs_per_size; |
---|
| 1020 | size_t bds_per_size; |
---|
| 1021 | |
---|
| 1022 | if (size > rtems_bdbuf_configuration.buffer_max) |
---|
| 1023 | return 0; |
---|
| 1024 | |
---|
| 1025 | bufs_per_size = ((size - 1) / bdbuf_config.buffer_min) + 1; |
---|
| 1026 | |
---|
| 1027 | for (bds_per_size = 1; |
---|
| 1028 | bds_per_size < bufs_per_size; |
---|
| 1029 | bds_per_size <<= 1) |
---|
| 1030 | ; |
---|
| 1031 | |
---|
| 1032 | return bdbuf_cache.max_bds_per_group / bds_per_size; |
---|
| 1033 | } |
---|
| 1034 | |
---|
| 1035 | /** |
---|
| 1036 | * Reallocate a group. The BDs currently allocated in the group are removed |
---|
| 1037 | * from the ALV tree and any lists then the new BD's are prepended to the ready |
---|
| 1038 | * list of the cache. |
---|
[e51bd96] | 1039 | * |
---|
[0d15414e] | 1040 | * @param group The group to reallocate. |
---|
| 1041 | * @param new_bds_per_group The new count of BDs per group. |
---|
[e51bd96] | 1042 | */ |
---|
[0d15414e] | 1043 | static void |
---|
| 1044 | rtems_bdbuf_group_realloc (rtems_bdbuf_group* group, size_t new_bds_per_group) |
---|
[e51bd96] | 1045 | { |
---|
[3899a537] | 1046 | rtems_bdbuf_buffer* bd; |
---|
[253c3a1d] | 1047 | size_t b; |
---|
[0d15414e] | 1048 | size_t bufs_per_bd; |
---|
[57aa979] | 1049 | |
---|
[eb649786] | 1050 | if (rtems_bdbuf_tracer) |
---|
[253c3a1d] | 1051 | printf ("bdbuf:realloc: %tu: %zd -> %zd\n", |
---|
[eb649786] | 1052 | group - bdbuf_cache.groups, group->bds_per_group, |
---|
| 1053 | new_bds_per_group); |
---|
| 1054 | |
---|
[0d15414e] | 1055 | bufs_per_bd = bdbuf_cache.max_bds_per_group / group->bds_per_group; |
---|
| 1056 | |
---|
| 1057 | for (b = 0, bd = group->bdbuf; |
---|
| 1058 | b < group->bds_per_group; |
---|
| 1059 | b++, bd += bufs_per_bd) |
---|
[57aa979] | 1060 | { |
---|
[eb649786] | 1061 | switch (bd->state) |
---|
[0d15414e] | 1062 | { |
---|
[eb649786] | 1063 | case RTEMS_BDBUF_STATE_EMPTY: |
---|
| 1064 | break; |
---|
| 1065 | case RTEMS_BDBUF_STATE_CACHED: |
---|
| 1066 | case RTEMS_BDBUF_STATE_READ_AHEAD: |
---|
| 1067 | if (rtems_bdbuf_avl_remove (&bdbuf_cache.tree, bd) != 0) |
---|
| 1068 | rtems_fatal_error_occurred ((bd->state << 16) | |
---|
| 1069 | RTEMS_BLKDEV_FATAL_BDBUF_CONSISTENCY_1); |
---|
| 1070 | break; |
---|
| 1071 | default: |
---|
[945884fe] | 1072 | rtems_fatal_error_occurred ((bd->state << 16) | |
---|
[eb649786] | 1073 | RTEMS_BLKDEV_FATAL_BDBUF_CONSISTENCY_8); |
---|
[0d15414e] | 1074 | } |
---|
[945884fe] | 1075 | |
---|
| 1076 | rtems_chain_extract (&bd->link); |
---|
[57aa979] | 1077 | } |
---|
[3899a537] | 1078 | |
---|
[0d15414e] | 1079 | group->bds_per_group = new_bds_per_group; |
---|
| 1080 | bufs_per_bd = bdbuf_cache.max_bds_per_group / new_bds_per_group; |
---|
| 1081 | |
---|
| 1082 | for (b = 0, bd = group->bdbuf; |
---|
| 1083 | b < group->bds_per_group; |
---|
| 1084 | b++, bd += bufs_per_bd) |
---|
[945884fe] | 1085 | { |
---|
| 1086 | bd->state = RTEMS_BDBUF_STATE_EMPTY; |
---|
[0d15414e] | 1087 | rtems_chain_prepend (&bdbuf_cache.ready, &bd->link); |
---|
[945884fe] | 1088 | } |
---|
[0d15414e] | 1089 | } |
---|
| 1090 | |
---|
| 1091 | /** |
---|
| 1092 | * Get the next BD from the list. This call assumes the cache is locked. |
---|
| 1093 | * |
---|
| 1094 | * @param bds_per_group The number of BDs per block we are need. |
---|
| 1095 | * @param list The list to find the BD on. |
---|
| 1096 | * @return The next BD if found or NULL is none are available. |
---|
| 1097 | */ |
---|
| 1098 | static rtems_bdbuf_buffer* |
---|
| 1099 | rtems_bdbuf_get_next_bd (size_t bds_per_group, |
---|
| 1100 | rtems_chain_control* list) |
---|
| 1101 | { |
---|
| 1102 | rtems_chain_node* node = rtems_chain_first (list); |
---|
| 1103 | while (!rtems_chain_is_tail (list, node)) |
---|
| 1104 | { |
---|
| 1105 | rtems_bdbuf_buffer* bd = (rtems_bdbuf_buffer*) node; |
---|
| 1106 | |
---|
[eb649786] | 1107 | if (rtems_bdbuf_tracer) |
---|
[253c3a1d] | 1108 | printf ("bdbuf:next-bd: %tu (%td:%" PRId32 ") %zd -> %zd\n", |
---|
[eb649786] | 1109 | bd - bdbuf_cache.bds, |
---|
| 1110 | bd->group - bdbuf_cache.groups, bd->group->users, |
---|
| 1111 | bd->group->bds_per_group, bds_per_group); |
---|
| 1112 | |
---|
[0d15414e] | 1113 | /* |
---|
| 1114 | * If this bd is already part of a group that supports the same number of |
---|
| 1115 | * BDs per group return it. If the bd is part of another group check the |
---|
| 1116 | * number of users and if 0 we can take this group and resize it. |
---|
| 1117 | */ |
---|
| 1118 | if (bd->group->bds_per_group == bds_per_group) |
---|
| 1119 | { |
---|
| 1120 | rtems_chain_extract (node); |
---|
| 1121 | return bd; |
---|
| 1122 | } |
---|
| 1123 | |
---|
| 1124 | if (bd->group->users == 0) |
---|
| 1125 | { |
---|
| 1126 | /* |
---|
| 1127 | * We use the group to locate the start of the BDs for this group. |
---|
| 1128 | */ |
---|
| 1129 | rtems_bdbuf_group_realloc (bd->group, bds_per_group); |
---|
| 1130 | bd = (rtems_bdbuf_buffer*) rtems_chain_get (&bdbuf_cache.ready); |
---|
| 1131 | return bd; |
---|
| 1132 | } |
---|
| 1133 | |
---|
| 1134 | node = rtems_chain_next (node); |
---|
| 1135 | } |
---|
[3899a537] | 1136 | |
---|
[0d15414e] | 1137 | return NULL; |
---|
| 1138 | } |
---|
| 1139 | |
---|
| 1140 | /** |
---|
| 1141 | * Initialise the cache. |
---|
| 1142 | * |
---|
| 1143 | * @return rtems_status_code The initialisation status. |
---|
| 1144 | */ |
---|
| 1145 | rtems_status_code |
---|
| 1146 | rtems_bdbuf_init (void) |
---|
| 1147 | { |
---|
| 1148 | rtems_bdbuf_group* group; |
---|
| 1149 | rtems_bdbuf_buffer* bd; |
---|
| 1150 | uint8_t* buffer; |
---|
| 1151 | int b; |
---|
| 1152 | int cache_aligment; |
---|
| 1153 | rtems_status_code sc; |
---|
| 1154 | |
---|
[eb649786] | 1155 | if (rtems_bdbuf_tracer) |
---|
| 1156 | printf ("bdbuf:init\n"); |
---|
[0d15414e] | 1157 | |
---|
[3899a537] | 1158 | /* |
---|
[0d15414e] | 1159 | * Check the configuration table values. |
---|
[3899a537] | 1160 | */ |
---|
[0d15414e] | 1161 | if ((bdbuf_config.buffer_max % bdbuf_config.buffer_min) != 0) |
---|
| 1162 | return RTEMS_INVALID_NUMBER; |
---|
[3899a537] | 1163 | |
---|
[0d15414e] | 1164 | /* |
---|
| 1165 | * We use a special variable to manage the initialisation incase we have |
---|
| 1166 | * completing threads doing this. You may get errors if the another thread |
---|
| 1167 | * makes a call and we have not finished initialisation. |
---|
| 1168 | */ |
---|
| 1169 | if (bdbuf_cache.initialised) |
---|
| 1170 | return RTEMS_RESOURCE_IN_USE; |
---|
[3899a537] | 1171 | |
---|
[0d15414e] | 1172 | bdbuf_cache.initialised = true; |
---|
| 1173 | |
---|
[3899a537] | 1174 | /* |
---|
[0d15414e] | 1175 | * For unspecified cache alignments we use the CPU alignment. |
---|
[3899a537] | 1176 | */ |
---|
[0d15414e] | 1177 | cache_aligment = 32; /* FIXME rtems_cache_get_data_line_size() */ |
---|
| 1178 | if (cache_aligment <= 0) |
---|
| 1179 | cache_aligment = CPU_ALIGNMENT; |
---|
[048dcd2b] | 1180 | |
---|
[0d15414e] | 1181 | bdbuf_cache.sync_active = false; |
---|
| 1182 | bdbuf_cache.sync_device = -1; |
---|
| 1183 | bdbuf_cache.sync_requester = 0; |
---|
| 1184 | bdbuf_cache.tree = NULL; |
---|
| 1185 | |
---|
| 1186 | rtems_chain_initialize_empty (&bdbuf_cache.swapout_workers); |
---|
| 1187 | rtems_chain_initialize_empty (&bdbuf_cache.ready); |
---|
| 1188 | rtems_chain_initialize_empty (&bdbuf_cache.lru); |
---|
| 1189 | rtems_chain_initialize_empty (&bdbuf_cache.modified); |
---|
| 1190 | rtems_chain_initialize_empty (&bdbuf_cache.sync); |
---|
| 1191 | |
---|
| 1192 | bdbuf_cache.access = 0; |
---|
| 1193 | bdbuf_cache.access_waiters = 0; |
---|
| 1194 | bdbuf_cache.transfer = 0; |
---|
| 1195 | bdbuf_cache.transfer_waiters = 0; |
---|
| 1196 | bdbuf_cache.waiting = 0; |
---|
| 1197 | bdbuf_cache.wait_waiters = 0; |
---|
[048dcd2b] | 1198 | |
---|
[0d15414e] | 1199 | /* |
---|
| 1200 | * Create the locks for the cache. |
---|
| 1201 | */ |
---|
| 1202 | sc = rtems_semaphore_create (rtems_build_name ('B', 'D', 'C', 'l'), |
---|
| 1203 | 1, RTEMS_BDBUF_CACHE_LOCK_ATTRIBS, 0, |
---|
| 1204 | &bdbuf_cache.lock); |
---|
[3899a537] | 1205 | if (sc != RTEMS_SUCCESSFUL) |
---|
| 1206 | { |
---|
[0d15414e] | 1207 | bdbuf_cache.initialised = false; |
---|
[3899a537] | 1208 | return sc; |
---|
| 1209 | } |
---|
[048dcd2b] | 1210 | |
---|
[0d15414e] | 1211 | rtems_bdbuf_lock_cache (); |
---|
| 1212 | |
---|
| 1213 | sc = rtems_semaphore_create (rtems_build_name ('B', 'D', 'C', 's'), |
---|
| 1214 | 1, RTEMS_BDBUF_CACHE_LOCK_ATTRIBS, 0, |
---|
| 1215 | &bdbuf_cache.sync_lock); |
---|
[3899a537] | 1216 | if (sc != RTEMS_SUCCESSFUL) |
---|
| 1217 | { |
---|
[0d15414e] | 1218 | rtems_bdbuf_unlock_cache (); |
---|
| 1219 | rtems_semaphore_delete (bdbuf_cache.lock); |
---|
| 1220 | bdbuf_cache.initialised = false; |
---|
[3899a537] | 1221 | return sc; |
---|
| 1222 | } |
---|
| 1223 | |
---|
[0d15414e] | 1224 | sc = rtems_semaphore_create (rtems_build_name ('B', 'D', 'C', 'a'), |
---|
| 1225 | 0, RTEMS_BDBUF_CACHE_WAITER_ATTRIBS, 0, |
---|
| 1226 | &bdbuf_cache.access); |
---|
[3899a537] | 1227 | if (sc != RTEMS_SUCCESSFUL) |
---|
| 1228 | { |
---|
[0d15414e] | 1229 | rtems_semaphore_delete (bdbuf_cache.sync_lock); |
---|
| 1230 | rtems_bdbuf_unlock_cache (); |
---|
| 1231 | rtems_semaphore_delete (bdbuf_cache.lock); |
---|
| 1232 | bdbuf_cache.initialised = false; |
---|
[3899a537] | 1233 | return sc; |
---|
| 1234 | } |
---|
[048dcd2b] | 1235 | |
---|
[0d15414e] | 1236 | sc = rtems_semaphore_create (rtems_build_name ('B', 'D', 'C', 't'), |
---|
| 1237 | 0, RTEMS_BDBUF_CACHE_WAITER_ATTRIBS, 0, |
---|
| 1238 | &bdbuf_cache.transfer); |
---|
[3899a537] | 1239 | if (sc != RTEMS_SUCCESSFUL) |
---|
| 1240 | { |
---|
[0d15414e] | 1241 | rtems_semaphore_delete (bdbuf_cache.access); |
---|
| 1242 | rtems_semaphore_delete (bdbuf_cache.sync_lock); |
---|
| 1243 | rtems_bdbuf_unlock_cache (); |
---|
| 1244 | rtems_semaphore_delete (bdbuf_cache.lock); |
---|
| 1245 | bdbuf_cache.initialised = false; |
---|
[3899a537] | 1246 | return sc; |
---|
| 1247 | } |
---|
| 1248 | |
---|
[0d15414e] | 1249 | sc = rtems_semaphore_create (rtems_build_name ('B', 'D', 'C', 'w'), |
---|
| 1250 | 0, RTEMS_BDBUF_CACHE_WAITER_ATTRIBS, 0, |
---|
| 1251 | &bdbuf_cache.waiting); |
---|
[3899a537] | 1252 | if (sc != RTEMS_SUCCESSFUL) |
---|
| 1253 | { |
---|
[0d15414e] | 1254 | rtems_semaphore_delete (bdbuf_cache.transfer); |
---|
| 1255 | rtems_semaphore_delete (bdbuf_cache.access); |
---|
| 1256 | rtems_semaphore_delete (bdbuf_cache.sync_lock); |
---|
| 1257 | rtems_bdbuf_unlock_cache (); |
---|
| 1258 | rtems_semaphore_delete (bdbuf_cache.lock); |
---|
| 1259 | bdbuf_cache.initialised = false; |
---|
[3899a537] | 1260 | return sc; |
---|
| 1261 | } |
---|
| 1262 | |
---|
[eb649786] | 1263 | /* |
---|
| 1264 | * Compute the various number of elements in the cache. |
---|
| 1265 | */ |
---|
| 1266 | bdbuf_cache.buffer_min_count = |
---|
| 1267 | bdbuf_config.size / bdbuf_config.buffer_min; |
---|
| 1268 | bdbuf_cache.max_bds_per_group = |
---|
| 1269 | bdbuf_config.buffer_max / bdbuf_config.buffer_min; |
---|
| 1270 | bdbuf_cache.group_count = |
---|
| 1271 | bdbuf_cache.buffer_min_count / bdbuf_cache.max_bds_per_group; |
---|
| 1272 | |
---|
[0d15414e] | 1273 | /* |
---|
| 1274 | * Allocate the memory for the buffer descriptors. |
---|
| 1275 | */ |
---|
| 1276 | bdbuf_cache.bds = calloc (sizeof (rtems_bdbuf_buffer), |
---|
[eb649786] | 1277 | bdbuf_cache.buffer_min_count); |
---|
[0d15414e] | 1278 | if (!bdbuf_cache.bds) |
---|
| 1279 | { |
---|
| 1280 | rtems_semaphore_delete (bdbuf_cache.transfer); |
---|
| 1281 | rtems_semaphore_delete (bdbuf_cache.access); |
---|
| 1282 | rtems_semaphore_delete (bdbuf_cache.sync_lock); |
---|
| 1283 | rtems_bdbuf_unlock_cache (); |
---|
| 1284 | rtems_semaphore_delete (bdbuf_cache.lock); |
---|
| 1285 | bdbuf_cache.initialised = false; |
---|
| 1286 | return RTEMS_NO_MEMORY; |
---|
| 1287 | } |
---|
[e51bd96] | 1288 | |
---|
[3899a537] | 1289 | /* |
---|
[0d15414e] | 1290 | * Allocate the memory for the buffer descriptors. |
---|
[3899a537] | 1291 | */ |
---|
[0d15414e] | 1292 | bdbuf_cache.groups = calloc (sizeof (rtems_bdbuf_group), |
---|
| 1293 | bdbuf_cache.group_count); |
---|
| 1294 | if (!bdbuf_cache.groups) |
---|
| 1295 | { |
---|
| 1296 | free (bdbuf_cache.bds); |
---|
| 1297 | rtems_semaphore_delete (bdbuf_cache.transfer); |
---|
| 1298 | rtems_semaphore_delete (bdbuf_cache.access); |
---|
| 1299 | rtems_semaphore_delete (bdbuf_cache.sync_lock); |
---|
| 1300 | rtems_bdbuf_unlock_cache (); |
---|
| 1301 | rtems_semaphore_delete (bdbuf_cache.lock); |
---|
| 1302 | bdbuf_cache.initialised = false; |
---|
| 1303 | return RTEMS_NO_MEMORY; |
---|
| 1304 | } |
---|
[3899a537] | 1305 | |
---|
[0d15414e] | 1306 | /* |
---|
| 1307 | * Allocate memory for buffer memory. The buffer memory will be cache |
---|
| 1308 | * aligned. It is possible to free the memory allocated by rtems_memalign() |
---|
| 1309 | * with free(). Return 0 if allocated. |
---|
[eb649786] | 1310 | * |
---|
| 1311 | * The memory allocate allows a |
---|
[0d15414e] | 1312 | */ |
---|
| 1313 | if (rtems_memalign ((void **) &bdbuf_cache.buffers, |
---|
| 1314 | cache_aligment, |
---|
| 1315 | bdbuf_cache.buffer_min_count * bdbuf_config.buffer_min) != 0) |
---|
| 1316 | { |
---|
| 1317 | free (bdbuf_cache.groups); |
---|
| 1318 | free (bdbuf_cache.bds); |
---|
| 1319 | rtems_semaphore_delete (bdbuf_cache.transfer); |
---|
| 1320 | rtems_semaphore_delete (bdbuf_cache.access); |
---|
| 1321 | rtems_semaphore_delete (bdbuf_cache.sync_lock); |
---|
| 1322 | rtems_bdbuf_unlock_cache (); |
---|
| 1323 | rtems_semaphore_delete (bdbuf_cache.lock); |
---|
| 1324 | bdbuf_cache.initialised = false; |
---|
[3899a537] | 1325 | return RTEMS_NO_MEMORY; |
---|
[0d15414e] | 1326 | } |
---|
[3899a537] | 1327 | |
---|
| 1328 | /* |
---|
[0d15414e] | 1329 | * The cache is empty after opening so we need to add all the buffers to it |
---|
| 1330 | * and initialise the groups. |
---|
[3899a537] | 1331 | */ |
---|
[0d15414e] | 1332 | for (b = 0, group = bdbuf_cache.groups, |
---|
| 1333 | bd = bdbuf_cache.bds, buffer = bdbuf_cache.buffers; |
---|
| 1334 | b < bdbuf_cache.buffer_min_count; |
---|
| 1335 | b++, bd++, buffer += bdbuf_config.buffer_min) |
---|
[3899a537] | 1336 | { |
---|
[0d15414e] | 1337 | bd->dev = -1; |
---|
| 1338 | bd->group = group; |
---|
| 1339 | bd->buffer = buffer; |
---|
| 1340 | bd->avl.left = NULL; |
---|
| 1341 | bd->avl.right = NULL; |
---|
| 1342 | bd->state = RTEMS_BDBUF_STATE_EMPTY; |
---|
| 1343 | bd->error = 0; |
---|
| 1344 | bd->waiters = 0; |
---|
| 1345 | bd->hold_timer = 0; |
---|
[eb649786] | 1346 | bd->references = 0; |
---|
| 1347 | bd->user = NULL; |
---|
[0d15414e] | 1348 | |
---|
| 1349 | rtems_chain_append (&bdbuf_cache.ready, &bd->link); |
---|
| 1350 | |
---|
| 1351 | if ((b % bdbuf_cache.max_bds_per_group) == |
---|
| 1352 | (bdbuf_cache.max_bds_per_group - 1)) |
---|
| 1353 | group++; |
---|
[3899a537] | 1354 | } |
---|
[e51bd96] | 1355 | |
---|
[0d15414e] | 1356 | for (b = 0, |
---|
| 1357 | group = bdbuf_cache.groups, |
---|
| 1358 | bd = bdbuf_cache.bds; |
---|
| 1359 | b < bdbuf_cache.group_count; |
---|
| 1360 | b++, |
---|
| 1361 | group++, |
---|
| 1362 | bd += bdbuf_cache.max_bds_per_group) |
---|
| 1363 | { |
---|
| 1364 | group->bds_per_group = bdbuf_cache.max_bds_per_group; |
---|
| 1365 | group->users = 0; |
---|
| 1366 | group->bdbuf = bd; |
---|
| 1367 | } |
---|
| 1368 | |
---|
[3899a537] | 1369 | /* |
---|
[0d15414e] | 1370 | * Create and start swapout task. This task will create and manage the worker |
---|
| 1371 | * threads. |
---|
[3899a537] | 1372 | */ |
---|
[0d15414e] | 1373 | bdbuf_cache.swapout_enabled = true; |
---|
[3899a537] | 1374 | |
---|
| 1375 | sc = rtems_task_create (rtems_build_name('B', 'S', 'W', 'P'), |
---|
[0d15414e] | 1376 | (bdbuf_config.swapout_priority ? |
---|
| 1377 | bdbuf_config.swapout_priority : |
---|
[3899a537] | 1378 | RTEMS_BDBUF_SWAPOUT_TASK_PRIORITY_DEFAULT), |
---|
| 1379 | SWAPOUT_TASK_STACK_SIZE, |
---|
| 1380 | RTEMS_PREEMPT | RTEMS_NO_TIMESLICE | RTEMS_NO_ASR, |
---|
| 1381 | RTEMS_LOCAL | RTEMS_NO_FLOATING_POINT, |
---|
[0d15414e] | 1382 | &bdbuf_cache.swapout); |
---|
[3899a537] | 1383 | if (sc != RTEMS_SUCCESSFUL) |
---|
| 1384 | { |
---|
[0d15414e] | 1385 | free (bdbuf_cache.buffers); |
---|
| 1386 | free (bdbuf_cache.groups); |
---|
| 1387 | free (bdbuf_cache.bds); |
---|
| 1388 | rtems_semaphore_delete (bdbuf_cache.transfer); |
---|
| 1389 | rtems_semaphore_delete (bdbuf_cache.access); |
---|
| 1390 | rtems_semaphore_delete (bdbuf_cache.sync_lock); |
---|
| 1391 | rtems_bdbuf_unlock_cache (); |
---|
| 1392 | rtems_semaphore_delete (bdbuf_cache.lock); |
---|
| 1393 | bdbuf_cache.initialised = false; |
---|
[3899a537] | 1394 | return sc; |
---|
| 1395 | } |
---|
[e51bd96] | 1396 | |
---|
[0d15414e] | 1397 | sc = rtems_task_start (bdbuf_cache.swapout, |
---|
[3899a537] | 1398 | rtems_bdbuf_swapout_task, |
---|
[0d15414e] | 1399 | (rtems_task_argument) &bdbuf_cache); |
---|
[3899a537] | 1400 | if (sc != RTEMS_SUCCESSFUL) |
---|
| 1401 | { |
---|
[0d15414e] | 1402 | rtems_task_delete (bdbuf_cache.swapout); |
---|
| 1403 | free (bdbuf_cache.buffers); |
---|
| 1404 | free (bdbuf_cache.groups); |
---|
| 1405 | free (bdbuf_cache.bds); |
---|
| 1406 | rtems_semaphore_delete (bdbuf_cache.transfer); |
---|
| 1407 | rtems_semaphore_delete (bdbuf_cache.access); |
---|
| 1408 | rtems_semaphore_delete (bdbuf_cache.sync_lock); |
---|
| 1409 | rtems_bdbuf_unlock_cache (); |
---|
| 1410 | rtems_semaphore_delete (bdbuf_cache.lock); |
---|
| 1411 | bdbuf_cache.initialised = false; |
---|
[3899a537] | 1412 | return sc; |
---|
| 1413 | } |
---|
[e51bd96] | 1414 | |
---|
[0d15414e] | 1415 | rtems_bdbuf_unlock_cache (); |
---|
| 1416 | |
---|
[3899a537] | 1417 | return RTEMS_SUCCESSFUL; |
---|
[e51bd96] | 1418 | } |
---|
| 1419 | |
---|
[3899a537] | 1420 | /** |
---|
| 1421 | * Get a buffer for this device and block. This function returns a buffer once |
---|
| 1422 | * placed into the AVL tree. If no buffer is available and it is not a read |
---|
[0d15414e] | 1423 | * ahead request and no buffers are waiting to the written to disk wait until a |
---|
| 1424 | * buffer is available. If buffers are waiting to be written to disk and none |
---|
| 1425 | * are available expire the hold timer's of the queued buffers and wake the |
---|
| 1426 | * swap out task. If the buffer is for a read ahead transfer return NULL if |
---|
| 1427 | * there are no buffers available or the buffer is already in the cache. |
---|
[e51bd96] | 1428 | * |
---|
[0d15414e] | 1429 | * The AVL tree of buffers for the cache is searched and if not found obtain a |
---|
| 1430 | * buffer and insert it into the AVL tree. Buffers are first obtained from the |
---|
| 1431 | * ready list until all empty/ready buffers are used. Once all buffers are in |
---|
| 1432 | * use the LRU list is searched for a buffer of the same group size or a group |
---|
| 1433 | * that has no active buffers in use. A buffer taken from the LRU list is |
---|
| 1434 | * removed from the AVL tree and assigned the new block number. The ready or |
---|
| 1435 | * LRU list buffer is initialised to this device and block. If no buffers are |
---|
| 1436 | * available due to the ready and LRU lists being empty a check is made of the |
---|
| 1437 | * modified list. Buffers may be queued waiting for the hold timer to |
---|
| 1438 | * expire. These buffers should be written to disk and returned to the LRU list |
---|
| 1439 | * where they can be used. If buffers are on the modified list the max. write |
---|
| 1440 | * block size of buffers have their hold timer's expired and the swap out task |
---|
| 1441 | * woken. The caller then blocks on the waiting semaphore and counter. When |
---|
| 1442 | * buffers return from the upper layers (access) or lower driver (transfer) the |
---|
| 1443 | * blocked caller task is woken and this procedure is repeated. The repeat |
---|
| 1444 | * handles a case of a another thread pre-empting getting a buffer first and |
---|
| 1445 | * adding it to the AVL tree. |
---|
[3899a537] | 1446 | * |
---|
| 1447 | * A buffer located in the AVL tree means it is already in the cache and maybe |
---|
| 1448 | * in use somewhere. The buffer can be either: |
---|
[e51bd96] | 1449 | * |
---|
[3899a537] | 1450 | * # Cached. Not being accessed or part of a media transfer. |
---|
[c21c850e] | 1451 | * # Access or modifed access. Is with an upper layer being accessed. |
---|
[3899a537] | 1452 | * # Transfer. Is with the driver and part of a media transfer. |
---|
| 1453 | * |
---|
[c21c850e] | 1454 | * If cached we assign the new state, extract it from any list it maybe part of |
---|
| 1455 | * and return to the user. |
---|
[3899a537] | 1456 | * |
---|
[0d15414e] | 1457 | * This function assumes the cache the buffer is being taken from is locked and |
---|
| 1458 | * it will make sure the cache is locked when it returns. The cache will be |
---|
[c21c850e] | 1459 | * unlocked if the call could block. |
---|
[3899a537] | 1460 | * |
---|
[0d15414e] | 1461 | * Variable sized buffer is handled by groups. A group is the size of the |
---|
| 1462 | * maximum buffer that can be allocated. The group can size in multiples of the |
---|
| 1463 | * minimum buffer size where the mulitples are 1,2,4,8, etc. If the buffer is |
---|
| 1464 | * found in the AVL tree the number of BDs in the group is check and if |
---|
| 1465 | * different the buffer size for the block has changed. The buffer needs to be |
---|
| 1466 | * invalidated. |
---|
[e51bd96] | 1467 | * |
---|
[0d15414e] | 1468 | * @param dd The disk device. Has the configured block size. |
---|
| 1469 | * @param bds_per_group The number of BDs in a group for this block. |
---|
| 1470 | * @param block Absolute media block number for the device |
---|
| 1471 | * @param read_ahead The get is for a read ahead buffer if true |
---|
| 1472 | * @return RTEMS status code (if operation completed successfully or error |
---|
[c21c850e] | 1473 | * code if error is occured) |
---|
[e51bd96] | 1474 | */ |
---|
[3899a537] | 1475 | static rtems_bdbuf_buffer* |
---|
[0d15414e] | 1476 | rtems_bdbuf_get_buffer (rtems_disk_device* dd, |
---|
| 1477 | size_t bds_per_group, |
---|
[3899a537] | 1478 | rtems_blkdev_bnum block, |
---|
[4f971343] | 1479 | bool read_ahead) |
---|
[e51bd96] | 1480 | { |
---|
[0d15414e] | 1481 | dev_t device = dd->dev; |
---|
[3899a537] | 1482 | rtems_bdbuf_buffer* bd; |
---|
[4f971343] | 1483 | bool available; |
---|
[0d15414e] | 1484 | |
---|
[3899a537] | 1485 | /* |
---|
| 1486 | * Loop until we get a buffer. Under load we could find no buffers are |
---|
[c21c850e] | 1487 | * available requiring this task to wait until some become available before |
---|
[0d15414e] | 1488 | * proceeding. There is no timeout. If this call is to block and the buffer |
---|
| 1489 | * is for a read ahead buffer return NULL. The read ahead is nice but not |
---|
| 1490 | * that important. |
---|
[3899a537] | 1491 | * |
---|
| 1492 | * The search procedure is repeated as another thread could have pre-empted |
---|
| 1493 | * us while we waited for a buffer, obtained an empty buffer and loaded the |
---|
[0d15414e] | 1494 | * AVL tree with the one we are after. In this case we move down and wait for |
---|
| 1495 | * the buffer to return to the cache. |
---|
[3899a537] | 1496 | */ |
---|
| 1497 | do |
---|
| 1498 | { |
---|
| 1499 | /* |
---|
| 1500 | * Search for buffer descriptor for this dev/block key. |
---|
| 1501 | */ |
---|
[0d15414e] | 1502 | bd = rtems_bdbuf_avl_search (&bdbuf_cache.tree, device, block); |
---|
[048dcd2b] | 1503 | |
---|
[3899a537] | 1504 | /* |
---|
| 1505 | * No buffer in the cache for this block. We need to obtain a buffer and |
---|
| 1506 | * this means take a buffer that is ready to use. If all buffers are in use |
---|
| 1507 | * take the least recently used buffer. If there are none then the cache is |
---|
| 1508 | * empty. All the buffers are either queued to be written to disk or with |
---|
| 1509 | * the user. We cannot do much with the buffers with the user how-ever with |
---|
| 1510 | * the modified buffers waiting to be written to disk flush the maximum |
---|
[c21c850e] | 1511 | * number transfered in a block to disk. After this all that can be done is |
---|
| 1512 | * to wait for a buffer to return to the cache. |
---|
[3899a537] | 1513 | */ |
---|
| 1514 | if (!bd) |
---|
[e51bd96] | 1515 | { |
---|
[3899a537] | 1516 | /* |
---|
[0d15414e] | 1517 | * Assign new buffer descriptor from the ready list if one is present. If |
---|
| 1518 | * the ready queue is empty get the oldest buffer from LRU list. If the |
---|
[c21c850e] | 1519 | * LRU list is empty there are no available buffers check the modified |
---|
| 1520 | * list. |
---|
[3899a537] | 1521 | */ |
---|
[0d15414e] | 1522 | bd = rtems_bdbuf_get_next_bd (bds_per_group, &bdbuf_cache.ready); |
---|
| 1523 | |
---|
| 1524 | if (!bd) |
---|
[3899a537] | 1525 | { |
---|
| 1526 | /* |
---|
[0d15414e] | 1527 | * No unused or read-ahead buffers. |
---|
[3899a537] | 1528 | * |
---|
[c21c850e] | 1529 | * If this is a read ahead buffer just return. No need to place further |
---|
| 1530 | * pressure on the cache by reading something that may be needed when |
---|
[0d15414e] | 1531 | * we have data in the cache that was needed and may still be in the |
---|
| 1532 | * future. |
---|
[3899a537] | 1533 | */ |
---|
| 1534 | if (read_ahead) |
---|
| 1535 | return NULL; |
---|
| 1536 | |
---|
| 1537 | /* |
---|
| 1538 | * Check the LRU list. |
---|
| 1539 | */ |
---|
[0d15414e] | 1540 | bd = rtems_bdbuf_get_next_bd (bds_per_group, &bdbuf_cache.lru); |
---|
[3899a537] | 1541 | |
---|
| 1542 | if (bd) |
---|
[e51bd96] | 1543 | { |
---|
[3899a537] | 1544 | /* |
---|
[eb649786] | 1545 | * Remove the buffer from the AVL tree if the state says it is in the |
---|
| 1546 | * cache or a read ahead buffer. The buffer could be in the empty |
---|
| 1547 | * state as a result of reallocations. |
---|
[3899a537] | 1548 | */ |
---|
[eb649786] | 1549 | switch (bd->state) |
---|
| 1550 | { |
---|
| 1551 | case RTEMS_BDBUF_STATE_CACHED: |
---|
| 1552 | case RTEMS_BDBUF_STATE_READ_AHEAD: |
---|
| 1553 | if (rtems_bdbuf_avl_remove (&bdbuf_cache.tree, bd) != 0) |
---|
| 1554 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_CONSISTENCY_2); |
---|
| 1555 | break; |
---|
| 1556 | default: |
---|
| 1557 | break; |
---|
| 1558 | } |
---|
[e51bd96] | 1559 | } |
---|
| 1560 | else |
---|
| 1561 | { |
---|
[3899a537] | 1562 | /* |
---|
| 1563 | * If there are buffers on the modified list expire the hold timer |
---|
[c21c850e] | 1564 | * and wake the swap out task then wait else just go and wait. |
---|
[0d15414e] | 1565 | * |
---|
| 1566 | * The check for an empty list is made so the swapper is only woken |
---|
| 1567 | * when if timers are changed. |
---|
[3899a537] | 1568 | */ |
---|
[0d15414e] | 1569 | if (!rtems_chain_is_empty (&bdbuf_cache.modified)) |
---|
[3899a537] | 1570 | { |
---|
[0d15414e] | 1571 | rtems_chain_node* node = rtems_chain_first (&bdbuf_cache.modified); |
---|
[cec5c069] | 1572 | uint32_t write_blocks = 0; |
---|
[3899a537] | 1573 | |
---|
[0d15414e] | 1574 | while ((write_blocks < bdbuf_config.max_write_blocks) && |
---|
| 1575 | !rtems_chain_is_tail (&bdbuf_cache.modified, node)) |
---|
[e51bd96] | 1576 | { |
---|
[3899a537] | 1577 | rtems_bdbuf_buffer* bd = (rtems_bdbuf_buffer*) node; |
---|
| 1578 | bd->hold_timer = 0; |
---|
| 1579 | write_blocks++; |
---|
[0d15414e] | 1580 | node = rtems_chain_next (node); |
---|
[e51bd96] | 1581 | } |
---|
| 1582 | |
---|
[3899a537] | 1583 | rtems_bdbuf_wake_swapper (); |
---|
| 1584 | } |
---|
| 1585 | |
---|
| 1586 | /* |
---|
[0d15414e] | 1587 | * Wait for a buffer to be returned to the cache. The buffer will be |
---|
[3899a537] | 1588 | * placed on the LRU list. |
---|
| 1589 | */ |
---|
[0d15414e] | 1590 | rtems_bdbuf_wait (&bdbuf_cache.waiting, &bdbuf_cache.wait_waiters); |
---|
[e51bd96] | 1591 | } |
---|
[3899a537] | 1592 | } |
---|
| 1593 | else |
---|
| 1594 | { |
---|
[0d15414e] | 1595 | /* |
---|
| 1596 | * We have a new buffer for this block. |
---|
| 1597 | */ |
---|
[3899a537] | 1598 | if ((bd->state != RTEMS_BDBUF_STATE_EMPTY) && |
---|
| 1599 | (bd->state != RTEMS_BDBUF_STATE_READ_AHEAD)) |
---|
[945884fe] | 1600 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_CONSISTENCY_3); |
---|
[3899a537] | 1601 | |
---|
| 1602 | if (bd->state == RTEMS_BDBUF_STATE_READ_AHEAD) |
---|
[e51bd96] | 1603 | { |
---|
[0d15414e] | 1604 | if (rtems_bdbuf_avl_remove (&bdbuf_cache.tree, bd) != 0) |
---|
[945884fe] | 1605 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_CONSISTENCY_4); |
---|
[e51bd96] | 1606 | } |
---|
[3899a537] | 1607 | } |
---|
| 1608 | |
---|
| 1609 | if (bd) |
---|
| 1610 | { |
---|
| 1611 | bd->dev = device; |
---|
| 1612 | bd->block = block; |
---|
| 1613 | bd->avl.left = NULL; |
---|
| 1614 | bd->avl.right = NULL; |
---|
| 1615 | bd->state = RTEMS_BDBUF_STATE_EMPTY; |
---|
| 1616 | bd->error = 0; |
---|
| 1617 | bd->waiters = 0; |
---|
| 1618 | |
---|
[0d15414e] | 1619 | if (rtems_bdbuf_avl_insert (&bdbuf_cache.tree, bd) != 0) |
---|
[945884fe] | 1620 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_CONSISTENCY_5); |
---|
[3899a537] | 1621 | |
---|
| 1622 | return bd; |
---|
| 1623 | } |
---|
[e51bd96] | 1624 | } |
---|
[0d15414e] | 1625 | else |
---|
| 1626 | { |
---|
| 1627 | /* |
---|
| 1628 | * We have the buffer for the block from the cache. Check if the buffer |
---|
| 1629 | * in the cache is the same size and the requested size we are after. |
---|
| 1630 | */ |
---|
| 1631 | if (bd->group->bds_per_group != bds_per_group) |
---|
| 1632 | { |
---|
[eb649786] | 1633 | /* |
---|
| 1634 | * Remove the buffer from the AVL tree. |
---|
| 1635 | */ |
---|
| 1636 | if (rtems_bdbuf_avl_remove (&bdbuf_cache.tree, bd) != 0) |
---|
| 1637 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_CONSISTENCY_2); |
---|
[0d15414e] | 1638 | bd->state = RTEMS_BDBUF_STATE_EMPTY; |
---|
| 1639 | rtems_chain_extract (&bd->link); |
---|
| 1640 | rtems_chain_prepend (&bdbuf_cache.ready, &bd->link); |
---|
| 1641 | bd = NULL; |
---|
| 1642 | } |
---|
| 1643 | } |
---|
[3899a537] | 1644 | } |
---|
| 1645 | while (!bd); |
---|
| 1646 | |
---|
| 1647 | /* |
---|
| 1648 | * If the buffer is for read ahead and it exists in the AVL cache or is being |
---|
[eb649786] | 1649 | * accessed or being transfered then return NULL stopping further read ahead |
---|
| 1650 | * requests. |
---|
[3899a537] | 1651 | */ |
---|
| 1652 | if (read_ahead) |
---|
| 1653 | return NULL; |
---|
| 1654 | |
---|
| 1655 | /* |
---|
[c21c850e] | 1656 | * Loop waiting for the buffer to enter the cached state. If the buffer is in |
---|
| 1657 | * the access or transfer state then wait until it is not. |
---|
[3899a537] | 1658 | */ |
---|
[4f971343] | 1659 | available = false; |
---|
[3899a537] | 1660 | while (!available) |
---|
| 1661 | { |
---|
| 1662 | switch (bd->state) |
---|
[e51bd96] | 1663 | { |
---|
[3899a537] | 1664 | case RTEMS_BDBUF_STATE_CACHED: |
---|
| 1665 | case RTEMS_BDBUF_STATE_MODIFIED: |
---|
| 1666 | case RTEMS_BDBUF_STATE_READ_AHEAD: |
---|
[4f971343] | 1667 | available = true; |
---|
[3899a537] | 1668 | break; |
---|
| 1669 | |
---|
| 1670 | case RTEMS_BDBUF_STATE_ACCESS: |
---|
| 1671 | case RTEMS_BDBUF_STATE_ACCESS_MODIFIED: |
---|
| 1672 | bd->waiters++; |
---|
[eb649786] | 1673 | rtems_bdbuf_wait (&bdbuf_cache.access, &bdbuf_cache.access_waiters); |
---|
[3899a537] | 1674 | bd->waiters--; |
---|
| 1675 | break; |
---|
| 1676 | |
---|
| 1677 | case RTEMS_BDBUF_STATE_SYNC: |
---|
| 1678 | case RTEMS_BDBUF_STATE_TRANSFER: |
---|
| 1679 | bd->waiters++; |
---|
[eb649786] | 1680 | rtems_bdbuf_wait (&bdbuf_cache.transfer, &bdbuf_cache.transfer_waiters); |
---|
[3899a537] | 1681 | bd->waiters--; |
---|
| 1682 | break; |
---|
| 1683 | |
---|
| 1684 | default: |
---|
[945884fe] | 1685 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_CONSISTENCY_6); |
---|
[e51bd96] | 1686 | } |
---|
[3899a537] | 1687 | } |
---|
[048dcd2b] | 1688 | |
---|
[3899a537] | 1689 | /* |
---|
| 1690 | * Buffer is linked to the LRU, modifed, or sync lists. Remove it from there. |
---|
| 1691 | */ |
---|
| 1692 | rtems_chain_extract (&bd->link); |
---|
[e51bd96] | 1693 | |
---|
[3899a537] | 1694 | return bd; |
---|
[e51bd96] | 1695 | } |
---|
| 1696 | |
---|
[3899a537] | 1697 | rtems_status_code |
---|
| 1698 | rtems_bdbuf_get (dev_t device, |
---|
| 1699 | rtems_blkdev_bnum block, |
---|
| 1700 | rtems_bdbuf_buffer** bdp) |
---|
[e51bd96] | 1701 | { |
---|
[3899a537] | 1702 | rtems_disk_device* dd; |
---|
| 1703 | rtems_bdbuf_buffer* bd; |
---|
[eb649786] | 1704 | rtems_blkdev_bnum media_block; |
---|
[0d15414e] | 1705 | size_t bds_per_group; |
---|
| 1706 | |
---|
| 1707 | if (!bdbuf_cache.initialised) |
---|
| 1708 | return RTEMS_NOT_CONFIGURED; |
---|
[3899a537] | 1709 | |
---|
| 1710 | /* |
---|
[0d15414e] | 1711 | * Do not hold the cache lock when obtaining the disk table. |
---|
[3899a537] | 1712 | */ |
---|
| 1713 | dd = rtems_disk_obtain (device); |
---|
[0d15414e] | 1714 | if (!dd) |
---|
[3899a537] | 1715 | return RTEMS_INVALID_ID; |
---|
| 1716 | |
---|
[eb649786] | 1717 | /* |
---|
| 1718 | * Compute the media block number. Drivers work with media block number not |
---|
| 1719 | * the block number a BD may have as this depends on the block size set by |
---|
| 1720 | * the user. |
---|
| 1721 | */ |
---|
| 1722 | media_block = rtems_bdbuf_media_block (block, |
---|
| 1723 | dd->block_size, |
---|
| 1724 | dd->media_block_size); |
---|
| 1725 | if (media_block >= dd->size) |
---|
[3899a537] | 1726 | { |
---|
[eb649786] | 1727 | rtems_disk_release(dd); |
---|
| 1728 | return RTEMS_INVALID_NUMBER; |
---|
[3899a537] | 1729 | } |
---|
| 1730 | |
---|
[0d15414e] | 1731 | bds_per_group = rtems_bdbuf_bds_per_group (dd->block_size); |
---|
| 1732 | if (!bds_per_group) |
---|
| 1733 | { |
---|
| 1734 | rtems_disk_release (dd); |
---|
| 1735 | return RTEMS_INVALID_NUMBER; |
---|
| 1736 | } |
---|
[eb649786] | 1737 | |
---|
| 1738 | media_block += dd->start; |
---|
| 1739 | |
---|
[0d15414e] | 1740 | rtems_bdbuf_lock_cache (); |
---|
[3899a537] | 1741 | |
---|
[eb649786] | 1742 | /* |
---|
| 1743 | * Print the block index relative to the physical disk. |
---|
| 1744 | */ |
---|
| 1745 | if (rtems_bdbuf_tracer) |
---|
| 1746 | printf ("bdbuf:get: %lu (%lu) (dev = %08x)\n", |
---|
| 1747 | media_block, block, (unsigned int) device); |
---|
[3899a537] | 1748 | |
---|
[eb649786] | 1749 | bd = rtems_bdbuf_get_buffer (dd, bds_per_group, media_block, false); |
---|
[3899a537] | 1750 | |
---|
[eb649786] | 1751 | /* |
---|
| 1752 | * This could be considered a bug in the caller because you should not be |
---|
| 1753 | * getting an already modified buffer but user may have modified a byte in a |
---|
| 1754 | * block then decided to seek the start and write the whole block and the |
---|
| 1755 | * file system will have no record of this so just gets the block to fill. |
---|
| 1756 | */ |
---|
[3899a537] | 1757 | if (bd->state == RTEMS_BDBUF_STATE_MODIFIED) |
---|
| 1758 | bd->state = RTEMS_BDBUF_STATE_ACCESS_MODIFIED; |
---|
| 1759 | else |
---|
[eb649786] | 1760 | { |
---|
[3899a537] | 1761 | bd->state = RTEMS_BDBUF_STATE_ACCESS; |
---|
[eb649786] | 1762 | /* |
---|
| 1763 | * Indicate a buffer in this group is being used. |
---|
| 1764 | */ |
---|
| 1765 | bd->group->users++; |
---|
| 1766 | } |
---|
[945884fe] | 1767 | |
---|
[eb649786] | 1768 | if (rtems_bdbuf_tracer) |
---|
| 1769 | { |
---|
| 1770 | rtems_bdbuf_show_users ("get", bd); |
---|
| 1771 | rtems_bdbuf_show_usage (); |
---|
| 1772 | } |
---|
| 1773 | |
---|
[0d15414e] | 1774 | rtems_bdbuf_unlock_cache (); |
---|
[3899a537] | 1775 | |
---|
[6f162ed] | 1776 | rtems_disk_release(dd); |
---|
| 1777 | |
---|
[3899a537] | 1778 | *bdp = bd; |
---|
[0d15414e] | 1779 | |
---|
[3899a537] | 1780 | return RTEMS_SUCCESSFUL; |
---|
[e51bd96] | 1781 | } |
---|
| 1782 | |
---|
[c21c850e] | 1783 | /** |
---|
| 1784 | * Call back handler called by the low level driver when the transfer has |
---|
| 1785 | * completed. This function may be invoked from interrupt handler. |
---|
[e51bd96] | 1786 | * |
---|
[c21c850e] | 1787 | * @param arg Arbitrary argument specified in block device request |
---|
| 1788 | * structure (in this case - pointer to the appropriate |
---|
| 1789 | * block device request structure). |
---|
| 1790 | * @param status I/O completion status |
---|
| 1791 | * @param error errno error code if status != RTEMS_SUCCESSFUL |
---|
[e51bd96] | 1792 | */ |
---|
| 1793 | static void |
---|
[3899a537] | 1794 | rtems_bdbuf_read_done (void* arg, rtems_status_code status, int error) |
---|
[e51bd96] | 1795 | { |
---|
[3899a537] | 1796 | rtems_blkdev_request* req = (rtems_blkdev_request*) arg; |
---|
| 1797 | |
---|
| 1798 | req->error = error; |
---|
| 1799 | req->status = status; |
---|
| 1800 | |
---|
| 1801 | rtems_event_send (req->io_task, RTEMS_BDBUF_TRANSFER_SYNC); |
---|
[e51bd96] | 1802 | } |
---|
| 1803 | |
---|
| 1804 | rtems_status_code |
---|
[3899a537] | 1805 | rtems_bdbuf_read (dev_t device, |
---|
| 1806 | rtems_blkdev_bnum block, |
---|
| 1807 | rtems_bdbuf_buffer** bdp) |
---|
[e51bd96] | 1808 | { |
---|
[3899a537] | 1809 | rtems_disk_device* dd; |
---|
| 1810 | rtems_bdbuf_buffer* bd = NULL; |
---|
[cec5c069] | 1811 | uint32_t read_ahead_count; |
---|
[3899a537] | 1812 | rtems_blkdev_request* req; |
---|
[0d15414e] | 1813 | size_t bds_per_group; |
---|
[eb649786] | 1814 | rtems_blkdev_bnum media_block; |
---|
| 1815 | rtems_blkdev_bnum media_block_count; |
---|
[3899a537] | 1816 | |
---|
[0d15414e] | 1817 | if (!bdbuf_cache.initialised) |
---|
| 1818 | return RTEMS_NOT_CONFIGURED; |
---|
| 1819 | |
---|
[3899a537] | 1820 | /* |
---|
| 1821 | * @todo This type of request structure is wrong and should be removed. |
---|
| 1822 | */ |
---|
| 1823 | #define bdbuf_alloc(size) __builtin_alloca (size) |
---|
| 1824 | |
---|
| 1825 | req = bdbuf_alloc (sizeof (rtems_blkdev_request) + |
---|
| 1826 | (sizeof ( rtems_blkdev_sg_buffer) * |
---|
| 1827 | rtems_bdbuf_configuration.max_read_ahead_blocks)); |
---|
| 1828 | |
---|
| 1829 | /* |
---|
[0d15414e] | 1830 | * Do not hold the cache lock when obtaining the disk table. |
---|
[3899a537] | 1831 | */ |
---|
| 1832 | dd = rtems_disk_obtain (device); |
---|
[0d15414e] | 1833 | if (!dd) |
---|
[3899a537] | 1834 | return RTEMS_INVALID_ID; |
---|
| 1835 | |
---|
[eb649786] | 1836 | /* |
---|
| 1837 | * Compute the media block number. Drivers work with media block number not |
---|
| 1838 | * the block number a BD may have as this depends on the block size set by |
---|
| 1839 | * the user. |
---|
| 1840 | */ |
---|
| 1841 | media_block = rtems_bdbuf_media_block (block, |
---|
| 1842 | dd->block_size, |
---|
| 1843 | dd->media_block_size); |
---|
| 1844 | if (media_block >= dd->size) |
---|
| 1845 | { |
---|
[3899a537] | 1846 | rtems_disk_release(dd); |
---|
| 1847 | return RTEMS_INVALID_NUMBER; |
---|
| 1848 | } |
---|
[57aa979] | 1849 | |
---|
[0d15414e] | 1850 | bds_per_group = rtems_bdbuf_bds_per_group (dd->block_size); |
---|
| 1851 | if (!bds_per_group) |
---|
| 1852 | { |
---|
| 1853 | rtems_disk_release (dd); |
---|
| 1854 | return RTEMS_INVALID_NUMBER; |
---|
| 1855 | } |
---|
| 1856 | |
---|
[eb649786] | 1857 | /* |
---|
| 1858 | * Print the block index relative to the physical disk and the user block |
---|
| 1859 | * number |
---|
| 1860 | */ |
---|
| 1861 | if (rtems_bdbuf_tracer) |
---|
| 1862 | printf ("bdbuf:read: %lu (%lu) (dev = %08x)\n", |
---|
| 1863 | media_block + dd->start, block, (unsigned int) device); |
---|
[e51bd96] | 1864 | |
---|
[3899a537] | 1865 | /* |
---|
| 1866 | * Read the block plus the required number of blocks ahead. The number of |
---|
| 1867 | * blocks to read ahead is configured by the user and limited by the size of |
---|
| 1868 | * the disk or reaching a read ahead block that is also cached. |
---|
| 1869 | * |
---|
| 1870 | * Limit the blocks read by the size of the disk. |
---|
| 1871 | */ |
---|
[eb649786] | 1872 | if ((rtems_bdbuf_configuration.max_read_ahead_blocks + media_block) < dd->size) |
---|
[3899a537] | 1873 | read_ahead_count = rtems_bdbuf_configuration.max_read_ahead_blocks; |
---|
| 1874 | else |
---|
[eb649786] | 1875 | read_ahead_count = dd->size - media_block; |
---|
| 1876 | |
---|
| 1877 | media_block_count = dd->block_size / dd->media_block_size; |
---|
| 1878 | |
---|
| 1879 | req->bufnum = 0; |
---|
[048dcd2b] | 1880 | |
---|
[0d15414e] | 1881 | rtems_bdbuf_lock_cache (); |
---|
[e51bd96] | 1882 | |
---|
[2eb89ad] | 1883 | while (req->bufnum < read_ahead_count) |
---|
[3899a537] | 1884 | { |
---|
| 1885 | /* |
---|
| 1886 | * Get the buffer for the requested block. If the block is cached then |
---|
| 1887 | * return it. If it is not cached transfer the block from the disk media |
---|
| 1888 | * into memory. |
---|
| 1889 | * |
---|
| 1890 | * We need to clean up any buffers allocated and not passed back to the |
---|
| 1891 | * caller. |
---|
| 1892 | */ |
---|
[eb649786] | 1893 | bd = rtems_bdbuf_get_buffer (dd, bds_per_group, media_block + dd->start, |
---|
[4f971343] | 1894 | req->bufnum == 0 ? false : true); |
---|
[e51bd96] | 1895 | |
---|
[3899a537] | 1896 | /* |
---|
| 1897 | * Read ahead buffer is in the cache or none available. Read what we |
---|
| 1898 | * can. |
---|
| 1899 | */ |
---|
| 1900 | if (!bd) |
---|
| 1901 | break; |
---|
[e51bd96] | 1902 | |
---|
[3899a537] | 1903 | /* |
---|
| 1904 | * Is the block we are interested in the cache ? |
---|
| 1905 | */ |
---|
| 1906 | if ((bd->state == RTEMS_BDBUF_STATE_CACHED) || |
---|
| 1907 | (bd->state == RTEMS_BDBUF_STATE_MODIFIED)) |
---|
| 1908 | break; |
---|
[048dcd2b] | 1909 | |
---|
[3899a537] | 1910 | bd->state = RTEMS_BDBUF_STATE_TRANSFER; |
---|
| 1911 | bd->error = 0; |
---|
[e51bd96] | 1912 | |
---|
[945884fe] | 1913 | /* |
---|
| 1914 | * The buffer will be passed to the driver so this buffer has a user. |
---|
| 1915 | */ |
---|
| 1916 | bd->group->users++; |
---|
[eb649786] | 1917 | |
---|
| 1918 | if (rtems_bdbuf_tracer) |
---|
| 1919 | rtems_bdbuf_show_users ("reading", bd); |
---|
[945884fe] | 1920 | |
---|
[3899a537] | 1921 | /* |
---|
[c21c850e] | 1922 | * @todo The use of these req blocks is not a great design. The req is a |
---|
| 1923 | * struct with a single 'bufs' declared in the req struct and the |
---|
| 1924 | * others are added in the outer level struct. This relies on the |
---|
| 1925 | * structs joining as a single array and that assumes the compiler |
---|
| 1926 | * packs the structs. Why not just place on a list ? The BD has a |
---|
| 1927 | * node that can be used. |
---|
[3899a537] | 1928 | */ |
---|
[2eb89ad] | 1929 | req->bufs[req->bufnum].user = bd; |
---|
[eb649786] | 1930 | req->bufs[req->bufnum].block = media_block + dd->start; |
---|
[2eb89ad] | 1931 | req->bufs[req->bufnum].length = dd->block_size; |
---|
| 1932 | req->bufs[req->bufnum].buffer = bd->buffer; |
---|
[3899a537] | 1933 | req->bufnum++; |
---|
[eb649786] | 1934 | |
---|
| 1935 | /* |
---|
| 1936 | * Move the media block count by the number of media blocks in the |
---|
| 1937 | * disk device's set block size. |
---|
| 1938 | */ |
---|
| 1939 | media_block += media_block_count; |
---|
[3899a537] | 1940 | } |
---|
[0ebfac19] | 1941 | |
---|
[3899a537] | 1942 | /* |
---|
| 1943 | * Transfer any requested buffers. If the request count is 0 we have found |
---|
| 1944 | * the block in the cache so return it. |
---|
| 1945 | */ |
---|
[2eb89ad] | 1946 | if (req->bufnum) |
---|
[3899a537] | 1947 | { |
---|
| 1948 | /* |
---|
[0d15414e] | 1949 | * Unlock the cache. We have the buffer for the block and it will be in the |
---|
[3899a537] | 1950 | * access or transfer state. We may also have a number of read ahead blocks |
---|
| 1951 | * if we need to transfer data. At this point any other threads can gain |
---|
[0d15414e] | 1952 | * access to the cache and if they are after any of the buffers we have |
---|
| 1953 | * they will block and be woken when the buffer is returned to the cache. |
---|
[3899a537] | 1954 | * |
---|
| 1955 | * If a transfer is needed the I/O operation will occur with pre-emption |
---|
[0d15414e] | 1956 | * enabled and the cache unlocked. This is a change to the previous version |
---|
[3899a537] | 1957 | * of the bdbuf code. |
---|
| 1958 | */ |
---|
[8c44190a] | 1959 | rtems_event_set out; |
---|
| 1960 | int result; |
---|
| 1961 | uint32_t b; |
---|
[eb649786] | 1962 | bool wake_transfer; |
---|
[8c44190a] | 1963 | |
---|
| 1964 | /* |
---|
| 1965 | * Flush any events. |
---|
| 1966 | */ |
---|
| 1967 | rtems_event_receive (RTEMS_BDBUF_TRANSFER_SYNC, |
---|
| 1968 | RTEMS_EVENT_ALL | RTEMS_NO_WAIT, |
---|
| 1969 | 0, &out); |
---|
| 1970 | |
---|
[0d15414e] | 1971 | rtems_bdbuf_unlock_cache (); |
---|
[3899a537] | 1972 | |
---|
| 1973 | req->req = RTEMS_BLKDEV_REQ_READ; |
---|
| 1974 | req->req_done = rtems_bdbuf_read_done; |
---|
| 1975 | req->done_arg = req; |
---|
| 1976 | req->io_task = rtems_task_self (); |
---|
| 1977 | req->status = RTEMS_RESOURCE_IN_USE; |
---|
| 1978 | req->error = 0; |
---|
| 1979 | |
---|
[b96e09c] | 1980 | result = dd->ioctl (dd, RTEMS_BLKIO_REQUEST, req); |
---|
[3899a537] | 1981 | |
---|
| 1982 | /* |
---|
| 1983 | * Inspection of the DOS FS code shows the result from this function is |
---|
| 1984 | * handled and a buffer must be returned. |
---|
| 1985 | */ |
---|
| 1986 | if (result < 0) |
---|
[0ebfac19] | 1987 | { |
---|
[3899a537] | 1988 | req->error = errno; |
---|
| 1989 | req->status = RTEMS_IO_ERROR; |
---|
| 1990 | } |
---|
| 1991 | else |
---|
| 1992 | { |
---|
| 1993 | rtems_status_code sc; |
---|
[8c44190a] | 1994 | |
---|
[3899a537] | 1995 | sc = rtems_event_receive (RTEMS_BDBUF_TRANSFER_SYNC, |
---|
| 1996 | RTEMS_EVENT_ALL | RTEMS_WAIT, |
---|
| 1997 | 0, &out); |
---|
| 1998 | |
---|
| 1999 | if (sc != RTEMS_SUCCESSFUL) |
---|
| 2000 | rtems_fatal_error_occurred (BLKDEV_FATAL_BDBUF_SWAPOUT_RE); |
---|
[0ebfac19] | 2001 | } |
---|
| 2002 | |
---|
[eb649786] | 2003 | wake_transfer = false; |
---|
| 2004 | |
---|
[0d15414e] | 2005 | rtems_bdbuf_lock_cache (); |
---|
[0ebfac19] | 2006 | |
---|
[2eb89ad] | 2007 | for (b = 1; b < req->bufnum; b++) |
---|
[0ebfac19] | 2008 | { |
---|
[3899a537] | 2009 | bd = req->bufs[b].user; |
---|
[eb649786] | 2010 | if (!bd->error) |
---|
| 2011 | bd->error = req->error; |
---|
[3899a537] | 2012 | bd->state = RTEMS_BDBUF_STATE_READ_AHEAD; |
---|
[945884fe] | 2013 | bd->group->users--; |
---|
[eb649786] | 2014 | |
---|
| 2015 | if (rtems_bdbuf_tracer) |
---|
| 2016 | rtems_bdbuf_show_users ("read-ahead", bd); |
---|
| 2017 | |
---|
[945884fe] | 2018 | rtems_chain_prepend (&bdbuf_cache.ready, &bd->link); |
---|
| 2019 | |
---|
| 2020 | /* |
---|
[eb649786] | 2021 | * If there is an error remove the BD from the AVL tree as it is invalid, |
---|
| 2022 | * then wake any threads that may be waiting. A thread may have been |
---|
| 2023 | * waiting for this block and assumed it was in the tree. |
---|
[945884fe] | 2024 | */ |
---|
| 2025 | if (bd->error) |
---|
| 2026 | { |
---|
| 2027 | bd->state = RTEMS_BDBUF_STATE_EMPTY; |
---|
| 2028 | if (rtems_bdbuf_avl_remove (&bdbuf_cache.tree, bd) != 0) |
---|
| 2029 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_CONSISTENCY_9); |
---|
| 2030 | } |
---|
| 2031 | |
---|
| 2032 | if (bd->waiters) |
---|
[eb649786] | 2033 | wake_transfer = true; |
---|
[0ebfac19] | 2034 | } |
---|
| 2035 | |
---|
[eb649786] | 2036 | if (wake_transfer) |
---|
| 2037 | rtems_bdbuf_wake (bdbuf_cache.transfer, &bdbuf_cache.transfer_waiters); |
---|
| 2038 | else |
---|
| 2039 | rtems_bdbuf_wake (bdbuf_cache.waiting, &bdbuf_cache.wait_waiters); |
---|
| 2040 | |
---|
[3899a537] | 2041 | bd = req->bufs[0].user; |
---|
[945884fe] | 2042 | |
---|
| 2043 | /* |
---|
[eb649786] | 2044 | * One less user for the BD we return. The loop above is only for the read |
---|
| 2045 | * head buffers. We do this here then increment again so the case of the |
---|
| 2046 | * buffer in the cache or modified and no read leaves the user counts at |
---|
| 2047 | * the correct level. |
---|
[945884fe] | 2048 | */ |
---|
| 2049 | bd->group->users--; |
---|
[eb649786] | 2050 | |
---|
| 2051 | if (rtems_bdbuf_tracer) |
---|
| 2052 | rtems_bdbuf_show_users ("read-done", bd); |
---|
[3899a537] | 2053 | } |
---|
[0ebfac19] | 2054 | |
---|
[3899a537] | 2055 | /* |
---|
| 2056 | * The data for this block is cached in the buffer. |
---|
| 2057 | */ |
---|
| 2058 | if (bd->state == RTEMS_BDBUF_STATE_MODIFIED) |
---|
| 2059 | bd->state = RTEMS_BDBUF_STATE_ACCESS_MODIFIED; |
---|
| 2060 | else |
---|
[945884fe] | 2061 | { |
---|
| 2062 | /* |
---|
| 2063 | * The file system is a user of the buffer. |
---|
| 2064 | */ |
---|
| 2065 | bd->group->users++; |
---|
[3899a537] | 2066 | bd->state = RTEMS_BDBUF_STATE_ACCESS; |
---|
[945884fe] | 2067 | } |
---|
[048dcd2b] | 2068 | |
---|
[eb649786] | 2069 | if (rtems_bdbuf_tracer) |
---|
| 2070 | { |
---|
| 2071 | rtems_bdbuf_show_users ("read", bd); |
---|
| 2072 | rtems_bdbuf_show_usage (); |
---|
| 2073 | } |
---|
| 2074 | |
---|
[0d15414e] | 2075 | rtems_bdbuf_unlock_cache (); |
---|
[3899a537] | 2076 | rtems_disk_release (dd); |
---|
[0ebfac19] | 2077 | |
---|
[3899a537] | 2078 | *bdp = bd; |
---|
[e51bd96] | 2079 | |
---|
[3899a537] | 2080 | return RTEMS_SUCCESSFUL; |
---|
| 2081 | } |
---|
[e51bd96] | 2082 | |
---|
[3899a537] | 2083 | rtems_status_code |
---|
| 2084 | rtems_bdbuf_release (rtems_bdbuf_buffer* bd) |
---|
[e51bd96] | 2085 | { |
---|
[0d15414e] | 2086 | if (!bdbuf_cache.initialised) |
---|
| 2087 | return RTEMS_NOT_CONFIGURED; |
---|
[e51bd96] | 2088 | |
---|
[3899a537] | 2089 | if (bd == NULL) |
---|
| 2090 | return RTEMS_INVALID_ADDRESS; |
---|
[048dcd2b] | 2091 | |
---|
[0d15414e] | 2092 | rtems_bdbuf_lock_cache (); |
---|
[e51bd96] | 2093 | |
---|
[eb649786] | 2094 | if (rtems_bdbuf_tracer) |
---|
| 2095 | printf ("bdbuf:release: %lu\n", bd->block); |
---|
[3899a537] | 2096 | |
---|
| 2097 | if (bd->state == RTEMS_BDBUF_STATE_ACCESS_MODIFIED) |
---|
| 2098 | { |
---|
[0d15414e] | 2099 | rtems_bdbuf_append_modified (bd); |
---|
[3899a537] | 2100 | } |
---|
| 2101 | else |
---|
| 2102 | { |
---|
[eb649786] | 2103 | bd->state = RTEMS_BDBUF_STATE_CACHED; |
---|
| 2104 | rtems_chain_append (&bdbuf_cache.lru, &bd->link); |
---|
[0d15414e] | 2105 | |
---|
| 2106 | /* |
---|
| 2107 | * One less user for the group of bds. |
---|
| 2108 | */ |
---|
| 2109 | bd->group->users--; |
---|
[3899a537] | 2110 | } |
---|
| 2111 | |
---|
[eb649786] | 2112 | if (rtems_bdbuf_tracer) |
---|
| 2113 | rtems_bdbuf_show_users ("release", bd); |
---|
| 2114 | |
---|
[3899a537] | 2115 | /* |
---|
| 2116 | * If there are threads waiting to access the buffer wake them. Wake any |
---|
[eb649786] | 2117 | * waiters if this buffer is placed back onto the LRU queue. |
---|
[3899a537] | 2118 | */ |
---|
| 2119 | if (bd->waiters) |
---|
[0d15414e] | 2120 | rtems_bdbuf_wake (bdbuf_cache.access, &bdbuf_cache.access_waiters); |
---|
[3899a537] | 2121 | else |
---|
[eb649786] | 2122 | rtems_bdbuf_wake (bdbuf_cache.waiting, &bdbuf_cache.wait_waiters); |
---|
| 2123 | |
---|
| 2124 | if (rtems_bdbuf_tracer) |
---|
| 2125 | rtems_bdbuf_show_usage (); |
---|
[3899a537] | 2126 | |
---|
[0d15414e] | 2127 | rtems_bdbuf_unlock_cache (); |
---|
[e51bd96] | 2128 | |
---|
[3899a537] | 2129 | return RTEMS_SUCCESSFUL; |
---|
| 2130 | } |
---|
[e51bd96] | 2131 | |
---|
| 2132 | rtems_status_code |
---|
[3899a537] | 2133 | rtems_bdbuf_release_modified (rtems_bdbuf_buffer* bd) |
---|
[e51bd96] | 2134 | { |
---|
[0d15414e] | 2135 | if (!bdbuf_cache.initialised) |
---|
| 2136 | return RTEMS_NOT_CONFIGURED; |
---|
[3899a537] | 2137 | |
---|
[0d15414e] | 2138 | if (!bd) |
---|
[3899a537] | 2139 | return RTEMS_INVALID_ADDRESS; |
---|
[e51bd96] | 2140 | |
---|
[0d15414e] | 2141 | rtems_bdbuf_lock_cache (); |
---|
[048dcd2b] | 2142 | |
---|
[eb649786] | 2143 | if (rtems_bdbuf_tracer) |
---|
| 2144 | printf ("bdbuf:release modified: %lu\n", bd->block); |
---|
[3899a537] | 2145 | |
---|
| 2146 | bd->hold_timer = rtems_bdbuf_configuration.swap_block_hold; |
---|
| 2147 | |
---|
[eb649786] | 2148 | if (rtems_bdbuf_tracer) |
---|
| 2149 | rtems_bdbuf_show_users ("release-modified", bd); |
---|
| 2150 | |
---|
[0d15414e] | 2151 | rtems_bdbuf_append_modified (bd); |
---|
[048dcd2b] | 2152 | |
---|
[3899a537] | 2153 | if (bd->waiters) |
---|
[0d15414e] | 2154 | rtems_bdbuf_wake (bdbuf_cache.access, &bdbuf_cache.access_waiters); |
---|
[3899a537] | 2155 | |
---|
[eb649786] | 2156 | if (rtems_bdbuf_tracer) |
---|
| 2157 | rtems_bdbuf_show_usage (); |
---|
| 2158 | |
---|
[0d15414e] | 2159 | rtems_bdbuf_unlock_cache (); |
---|
[048dcd2b] | 2160 | |
---|
[3899a537] | 2161 | return RTEMS_SUCCESSFUL; |
---|
[e51bd96] | 2162 | } |
---|
| 2163 | |
---|
| 2164 | rtems_status_code |
---|
[3899a537] | 2165 | rtems_bdbuf_sync (rtems_bdbuf_buffer* bd) |
---|
[e51bd96] | 2166 | { |
---|
[0d15414e] | 2167 | bool available; |
---|
[3899a537] | 2168 | |
---|
[eb649786] | 2169 | if (rtems_bdbuf_tracer) |
---|
| 2170 | printf ("bdbuf:sync: %lu\n", bd->block); |
---|
[3899a537] | 2171 | |
---|
[0d15414e] | 2172 | if (!bdbuf_cache.initialised) |
---|
| 2173 | return RTEMS_NOT_CONFIGURED; |
---|
[3899a537] | 2174 | |
---|
[0d15414e] | 2175 | if (!bd) |
---|
| 2176 | return RTEMS_INVALID_ADDRESS; |
---|
[3899a537] | 2177 | |
---|
[0d15414e] | 2178 | rtems_bdbuf_lock_cache (); |
---|
[3899a537] | 2179 | |
---|
| 2180 | bd->state = RTEMS_BDBUF_STATE_SYNC; |
---|
[e51bd96] | 2181 | |
---|
[0d15414e] | 2182 | rtems_chain_append (&bdbuf_cache.sync, &bd->link); |
---|
[048dcd2b] | 2183 | |
---|
[3899a537] | 2184 | rtems_bdbuf_wake_swapper (); |
---|
[e51bd96] | 2185 | |
---|
[4f971343] | 2186 | available = false; |
---|
[3899a537] | 2187 | while (!available) |
---|
| 2188 | { |
---|
| 2189 | switch (bd->state) |
---|
[e51bd96] | 2190 | { |
---|
[3899a537] | 2191 | case RTEMS_BDBUF_STATE_CACHED: |
---|
| 2192 | case RTEMS_BDBUF_STATE_READ_AHEAD: |
---|
| 2193 | case RTEMS_BDBUF_STATE_MODIFIED: |
---|
| 2194 | case RTEMS_BDBUF_STATE_ACCESS: |
---|
| 2195 | case RTEMS_BDBUF_STATE_ACCESS_MODIFIED: |
---|
[4f971343] | 2196 | available = true; |
---|
[3899a537] | 2197 | break; |
---|
| 2198 | |
---|
| 2199 | case RTEMS_BDBUF_STATE_SYNC: |
---|
| 2200 | case RTEMS_BDBUF_STATE_TRANSFER: |
---|
| 2201 | bd->waiters++; |
---|
[eb649786] | 2202 | rtems_bdbuf_wait (&bdbuf_cache.transfer, &bdbuf_cache.transfer_waiters); |
---|
[3899a537] | 2203 | bd->waiters--; |
---|
| 2204 | break; |
---|
| 2205 | |
---|
| 2206 | default: |
---|
[945884fe] | 2207 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_CONSISTENCY_7); |
---|
[e51bd96] | 2208 | } |
---|
[3899a537] | 2209 | } |
---|
[048dcd2b] | 2210 | |
---|
[0d15414e] | 2211 | rtems_bdbuf_unlock_cache (); |
---|
[3899a537] | 2212 | |
---|
| 2213 | return RTEMS_SUCCESSFUL; |
---|
[e51bd96] | 2214 | } |
---|
| 2215 | |
---|
| 2216 | rtems_status_code |
---|
[3899a537] | 2217 | rtems_bdbuf_syncdev (dev_t dev) |
---|
[e51bd96] | 2218 | { |
---|
[3899a537] | 2219 | rtems_disk_device* dd; |
---|
| 2220 | rtems_status_code sc; |
---|
| 2221 | rtems_event_set out; |
---|
[e51bd96] | 2222 | |
---|
[eb649786] | 2223 | if (rtems_bdbuf_tracer) |
---|
| 2224 | printf ("bdbuf:syncdev: %08x\n", (unsigned int) dev); |
---|
[e51bd96] | 2225 | |
---|
[0d15414e] | 2226 | if (!bdbuf_cache.initialised) |
---|
| 2227 | return RTEMS_NOT_CONFIGURED; |
---|
| 2228 | |
---|
[3899a537] | 2229 | /* |
---|
[0d15414e] | 2230 | * Do not hold the cache lock when obtaining the disk table. |
---|
[3899a537] | 2231 | */ |
---|
| 2232 | dd = rtems_disk_obtain (dev); |
---|
[0d15414e] | 2233 | if (!dd) |
---|
[3899a537] | 2234 | return RTEMS_INVALID_ID; |
---|
| 2235 | |
---|
| 2236 | /* |
---|
[0d15414e] | 2237 | * Take the sync lock before locking the cache. Once we have the sync lock we |
---|
| 2238 | * can lock the cache. If another thread has the sync lock it will cause this |
---|
| 2239 | * thread to block until it owns the sync lock then it can own the cache. The |
---|
| 2240 | * sync lock can only be obtained with the cache unlocked. |
---|
[3899a537] | 2241 | */ |
---|
| 2242 | |
---|
[0d15414e] | 2243 | rtems_bdbuf_lock_sync (); |
---|
| 2244 | rtems_bdbuf_lock_cache (); |
---|
[e51bd96] | 2245 | |
---|
[c21c850e] | 2246 | /* |
---|
[0d15414e] | 2247 | * Set the cache to have a sync active for a specific device and let the swap |
---|
[c21c850e] | 2248 | * out task know the id of the requester to wake when done. |
---|
| 2249 | * |
---|
| 2250 | * The swap out task will negate the sync active flag when no more buffers |
---|
[0d15414e] | 2251 | * for the device are held on the "modified for sync" queues. |
---|
[c21c850e] | 2252 | */ |
---|
[0d15414e] | 2253 | bdbuf_cache.sync_active = true; |
---|
| 2254 | bdbuf_cache.sync_requester = rtems_task_self (); |
---|
| 2255 | bdbuf_cache.sync_device = dev; |
---|
[3899a537] | 2256 | |
---|
| 2257 | rtems_bdbuf_wake_swapper (); |
---|
[0d15414e] | 2258 | rtems_bdbuf_unlock_cache (); |
---|
[3899a537] | 2259 | |
---|
| 2260 | sc = rtems_event_receive (RTEMS_BDBUF_TRANSFER_SYNC, |
---|
| 2261 | RTEMS_EVENT_ALL | RTEMS_WAIT, |
---|
| 2262 | 0, &out); |
---|
[e51bd96] | 2263 | |
---|
[3899a537] | 2264 | if (sc != RTEMS_SUCCESSFUL) |
---|
| 2265 | rtems_fatal_error_occurred (BLKDEV_FATAL_BDBUF_SWAPOUT_RE); |
---|
| 2266 | |
---|
[0d15414e] | 2267 | rtems_bdbuf_unlock_sync (); |
---|
[3899a537] | 2268 | |
---|
[0d15414e] | 2269 | return rtems_disk_release (dd); |
---|
[e51bd96] | 2270 | } |
---|
| 2271 | |
---|
[c21c850e] | 2272 | /** |
---|
| 2273 | * Call back handler called by the low level driver when the transfer has |
---|
[eb649786] | 2274 | * completed. This function may be invoked from interrupt handlers. |
---|
[e51bd96] | 2275 | * |
---|
[c21c850e] | 2276 | * @param arg Arbitrary argument specified in block device request |
---|
| 2277 | * structure (in this case - pointer to the appropriate |
---|
| 2278 | * block device request structure). |
---|
| 2279 | * @param status I/O completion status |
---|
| 2280 | * @param error errno error code if status != RTEMS_SUCCESSFUL |
---|
[e51bd96] | 2281 | */ |
---|
[3899a537] | 2282 | static void |
---|
| 2283 | rtems_bdbuf_write_done(void *arg, rtems_status_code status, int error) |
---|
| 2284 | { |
---|
| 2285 | rtems_blkdev_request* req = (rtems_blkdev_request*) arg; |
---|
| 2286 | |
---|
| 2287 | req->error = error; |
---|
| 2288 | req->status = status; |
---|
| 2289 | |
---|
| 2290 | rtems_event_send (req->io_task, RTEMS_BDBUF_TRANSFER_SYNC); |
---|
| 2291 | } |
---|
| 2292 | |
---|
| 2293 | /** |
---|
[0d15414e] | 2294 | * Swapout transfer to the driver. The driver will break this I/O into groups |
---|
| 2295 | * of consecutive write requests is multiple consecutive buffers are required |
---|
| 2296 | * by the driver. |
---|
[c21c850e] | 2297 | * |
---|
[0d15414e] | 2298 | * @param transfer The transfer transaction. |
---|
[3899a537] | 2299 | */ |
---|
| 2300 | static void |
---|
[0d15414e] | 2301 | rtems_bdbuf_swapout_write (rtems_bdbuf_swapout_transfer* transfer) |
---|
[e51bd96] | 2302 | { |
---|
[eb649786] | 2303 | rtems_disk_device* dd; |
---|
[3899a537] | 2304 | |
---|
[eb649786] | 2305 | if (rtems_bdbuf_tracer) |
---|
| 2306 | printf ("bdbuf:swapout transfer: %08x\n", (unsigned int) transfer->dev); |
---|
[3899a537] | 2307 | |
---|
| 2308 | /* |
---|
[7baa484] | 2309 | * If there are buffers to transfer to the media transfer them. |
---|
[3899a537] | 2310 | */ |
---|
[0d15414e] | 2311 | if (!rtems_chain_is_empty (&transfer->bds)) |
---|
[3899a537] | 2312 | { |
---|
| 2313 | /* |
---|
[0d15414e] | 2314 | * Obtain the disk device. The cache's mutex has been released to avoid a |
---|
[7baa484] | 2315 | * dead lock. |
---|
[3899a537] | 2316 | */ |
---|
[0d15414e] | 2317 | dd = rtems_disk_obtain (transfer->dev); |
---|
| 2318 | if (dd) |
---|
[3899a537] | 2319 | { |
---|
| 2320 | /* |
---|
| 2321 | * The last block number used when the driver only supports |
---|
| 2322 | * continuous blocks in a single request. |
---|
| 2323 | */ |
---|
| 2324 | uint32_t last_block = 0; |
---|
[eb649786] | 2325 | |
---|
| 2326 | /* |
---|
| 2327 | * Number of buffers per bd. This is used to detect the next |
---|
| 2328 | * block. |
---|
| 2329 | */ |
---|
| 2330 | uint32_t bufs_per_bd = dd->block_size / bdbuf_config.buffer_min; |
---|
[3899a537] | 2331 | |
---|
| 2332 | /* |
---|
[c21c850e] | 2333 | * Take as many buffers as configured and pass to the driver. Note, the |
---|
[7baa484] | 2334 | * API to the drivers has an array of buffers and if a chain was passed |
---|
[c21c850e] | 2335 | * we could have just passed the list. If the driver API is updated it |
---|
| 2336 | * should be possible to make this change with little effect in this |
---|
| 2337 | * code. The array that is passed is broken in design and should be |
---|
[7baa484] | 2338 | * removed. Merging members of a struct into the first member is |
---|
[c21c850e] | 2339 | * trouble waiting to happen. |
---|
[3899a537] | 2340 | */ |
---|
[0d15414e] | 2341 | transfer->write_req->status = RTEMS_RESOURCE_IN_USE; |
---|
| 2342 | transfer->write_req->error = 0; |
---|
| 2343 | transfer->write_req->bufnum = 0; |
---|
[3899a537] | 2344 | |
---|
[0d15414e] | 2345 | while (!rtems_chain_is_empty (&transfer->bds)) |
---|
[3899a537] | 2346 | { |
---|
| 2347 | rtems_bdbuf_buffer* bd = |
---|
[0d15414e] | 2348 | (rtems_bdbuf_buffer*) rtems_chain_get (&transfer->bds); |
---|
[3899a537] | 2349 | |
---|
[8c5d3743] | 2350 | bool write = false; |
---|
[3899a537] | 2351 | |
---|
| 2352 | /* |
---|
[c21c850e] | 2353 | * If the device only accepts sequential buffers and this is not the |
---|
| 2354 | * first buffer (the first is always sequential, and the buffer is not |
---|
| 2355 | * sequential then put the buffer back on the transfer chain and write |
---|
| 2356 | * the committed buffers. |
---|
[3899a537] | 2357 | */ |
---|
| 2358 | |
---|
[eb649786] | 2359 | if (rtems_bdbuf_tracer) |
---|
| 2360 | printf ("bdbuf:swapout write: bd:%lu, bufnum:%lu mode:%s\n", |
---|
| 2361 | bd->block, transfer->write_req->bufnum, |
---|
| 2362 | dd->phys_dev->capabilities & |
---|
| 2363 | RTEMS_BLKDEV_CAP_MULTISECTOR_CONT ? "MULIT" : "SCAT"); |
---|
| 2364 | |
---|
[0d15414e] | 2365 | if ((dd->phys_dev->capabilities & RTEMS_BLKDEV_CAP_MULTISECTOR_CONT) && |
---|
| 2366 | transfer->write_req->bufnum && |
---|
[eb649786] | 2367 | (bd->block != (last_block + bufs_per_bd))) |
---|
[3899a537] | 2368 | { |
---|
[0d15414e] | 2369 | rtems_chain_prepend (&transfer->bds, &bd->link); |
---|
[4f971343] | 2370 | write = true; |
---|
[3899a537] | 2371 | } |
---|
| 2372 | else |
---|
| 2373 | { |
---|
[0d15414e] | 2374 | rtems_blkdev_sg_buffer* buf; |
---|
| 2375 | buf = &transfer->write_req->bufs[transfer->write_req->bufnum]; |
---|
| 2376 | transfer->write_req->bufnum++; |
---|
| 2377 | buf->user = bd; |
---|
| 2378 | buf->block = bd->block; |
---|
| 2379 | buf->length = dd->block_size; |
---|
| 2380 | buf->buffer = bd->buffer; |
---|
| 2381 | last_block = bd->block; |
---|
[3899a537] | 2382 | } |
---|
| 2383 | |
---|
| 2384 | /* |
---|
[c21c850e] | 2385 | * Perform the transfer if there are no more buffers, or the transfer |
---|
| 2386 | * size has reached the configured max. value. |
---|
[3899a537] | 2387 | */ |
---|
[048dcd2b] | 2388 | |
---|
[0d15414e] | 2389 | if (rtems_chain_is_empty (&transfer->bds) || |
---|
| 2390 | (transfer->write_req->bufnum >= rtems_bdbuf_configuration.max_write_blocks)) |
---|
[4f971343] | 2391 | write = true; |
---|
[048dcd2b] | 2392 | |
---|
[3899a537] | 2393 | if (write) |
---|
[e51bd96] | 2394 | { |
---|
[3899a537] | 2395 | int result; |
---|
[cec5c069] | 2396 | uint32_t b; |
---|
[3899a537] | 2397 | |
---|
[eb649786] | 2398 | if (rtems_bdbuf_tracer) |
---|
| 2399 | printf ("bdbuf:swapout write: writing bufnum:%lu\n", |
---|
| 2400 | transfer->write_req->bufnum); |
---|
| 2401 | |
---|
[3899a537] | 2402 | /* |
---|
[0d15414e] | 2403 | * Perform the transfer. No cache locks, no preemption, only the disk |
---|
[c21c850e] | 2404 | * device is being held. |
---|
[3899a537] | 2405 | */ |
---|
[b96e09c] | 2406 | result = dd->ioctl (dd, RTEMS_BLKIO_REQUEST, transfer->write_req); |
---|
[3899a537] | 2407 | if (result < 0) |
---|
| 2408 | { |
---|
[0d15414e] | 2409 | rtems_bdbuf_lock_cache (); |
---|
[3899a537] | 2410 | |
---|
[0d15414e] | 2411 | for (b = 0; b < transfer->write_req->bufnum; b++) |
---|
[3899a537] | 2412 | { |
---|
[0d15414e] | 2413 | bd = transfer->write_req->bufs[b].user; |
---|
[3899a537] | 2414 | bd->state = RTEMS_BDBUF_STATE_MODIFIED; |
---|
| 2415 | bd->error = errno; |
---|
| 2416 | |
---|
| 2417 | /* |
---|
[0d15414e] | 2418 | * Place back on the cache's modified queue and try again. |
---|
[3899a537] | 2419 | * |
---|
[c21c850e] | 2420 | * @warning Not sure this is the best option but I do not know |
---|
| 2421 | * what else can be done. |
---|
[3899a537] | 2422 | */ |
---|
[0d15414e] | 2423 | rtems_chain_append (&bdbuf_cache.modified, &bd->link); |
---|
[3899a537] | 2424 | } |
---|
| 2425 | } |
---|
| 2426 | else |
---|
| 2427 | { |
---|
| 2428 | rtems_status_code sc = 0; |
---|
| 2429 | rtems_event_set out; |
---|
| 2430 | |
---|
| 2431 | sc = rtems_event_receive (RTEMS_BDBUF_TRANSFER_SYNC, |
---|
| 2432 | RTEMS_EVENT_ALL | RTEMS_WAIT, |
---|
| 2433 | 0, &out); |
---|
| 2434 | |
---|
| 2435 | if (sc != RTEMS_SUCCESSFUL) |
---|
| 2436 | rtems_fatal_error_occurred (BLKDEV_FATAL_BDBUF_SWAPOUT_RE); |
---|
| 2437 | |
---|
[0d15414e] | 2438 | rtems_bdbuf_lock_cache (); |
---|
[3899a537] | 2439 | |
---|
[0d15414e] | 2440 | for (b = 0; b < transfer->write_req->bufnum; b++) |
---|
[3899a537] | 2441 | { |
---|
[0d15414e] | 2442 | bd = transfer->write_req->bufs[b].user; |
---|
[3899a537] | 2443 | bd->state = RTEMS_BDBUF_STATE_CACHED; |
---|
| 2444 | bd->error = 0; |
---|
[945884fe] | 2445 | |
---|
| 2446 | /* |
---|
| 2447 | * The buffer is now not modified so lower the user count for the group. |
---|
| 2448 | */ |
---|
[0d15414e] | 2449 | bd->group->users--; |
---|
[eb649786] | 2450 | |
---|
| 2451 | if (rtems_bdbuf_tracer) |
---|
| 2452 | rtems_bdbuf_show_users ("write", bd); |
---|
| 2453 | |
---|
[0d15414e] | 2454 | rtems_chain_append (&bdbuf_cache.lru, &bd->link); |
---|
[3899a537] | 2455 | |
---|
| 2456 | if (bd->waiters) |
---|
[0d15414e] | 2457 | rtems_bdbuf_wake (bdbuf_cache.transfer, &bdbuf_cache.transfer_waiters); |
---|
[3899a537] | 2458 | else |
---|
[eb649786] | 2459 | rtems_bdbuf_wake (bdbuf_cache.waiting, &bdbuf_cache.wait_waiters); |
---|
[3899a537] | 2460 | } |
---|
| 2461 | } |
---|
[eb649786] | 2462 | |
---|
| 2463 | if (rtems_bdbuf_tracer) |
---|
| 2464 | rtems_bdbuf_show_usage (); |
---|
| 2465 | |
---|
[0d15414e] | 2466 | rtems_bdbuf_unlock_cache (); |
---|
[3899a537] | 2467 | |
---|
[0d15414e] | 2468 | transfer->write_req->status = RTEMS_RESOURCE_IN_USE; |
---|
| 2469 | transfer->write_req->error = 0; |
---|
| 2470 | transfer->write_req->bufnum = 0; |
---|
[e51bd96] | 2471 | } |
---|
[3899a537] | 2472 | } |
---|
| 2473 | |
---|
| 2474 | rtems_disk_release (dd); |
---|
| 2475 | } |
---|
[0d15414e] | 2476 | else |
---|
| 2477 | { |
---|
| 2478 | /* |
---|
| 2479 | * We have buffers but no device. Put the BDs back onto the |
---|
| 2480 | * ready queue and exit. |
---|
| 2481 | */ |
---|
| 2482 | /* @todo fixme */ |
---|
| 2483 | } |
---|
| 2484 | } |
---|
| 2485 | } |
---|
| 2486 | |
---|
| 2487 | /** |
---|
| 2488 | * Process the modified list of buffers. There is a sync or modified list that |
---|
| 2489 | * needs to be handled so we have a common function to do the work. |
---|
| 2490 | * |
---|
| 2491 | * @param dev The device to handle. If -1 no device is selected so select the |
---|
| 2492 | * device of the first buffer to be written to disk. |
---|
| 2493 | * @param chain The modified chain to process. |
---|
| 2494 | * @param transfer The chain to append buffers to be written too. |
---|
| 2495 | * @param sync_active If true this is a sync operation so expire all timers. |
---|
| 2496 | * @param update_timers If true update the timers. |
---|
| 2497 | * @param timer_delta It update_timers is true update the timers by this |
---|
| 2498 | * amount. |
---|
| 2499 | */ |
---|
| 2500 | static void |
---|
| 2501 | rtems_bdbuf_swapout_modified_processing (dev_t* dev, |
---|
| 2502 | rtems_chain_control* chain, |
---|
| 2503 | rtems_chain_control* transfer, |
---|
| 2504 | bool sync_active, |
---|
| 2505 | bool update_timers, |
---|
| 2506 | uint32_t timer_delta) |
---|
| 2507 | { |
---|
| 2508 | if (!rtems_chain_is_empty (chain)) |
---|
| 2509 | { |
---|
| 2510 | rtems_chain_node* node = rtems_chain_head (chain); |
---|
| 2511 | node = node->next; |
---|
| 2512 | |
---|
| 2513 | while (!rtems_chain_is_tail (chain, node)) |
---|
| 2514 | { |
---|
| 2515 | rtems_bdbuf_buffer* bd = (rtems_bdbuf_buffer*) node; |
---|
| 2516 | |
---|
| 2517 | /* |
---|
| 2518 | * Check if the buffer's hold timer has reached 0. If a sync is active |
---|
| 2519 | * force all the timers to 0. |
---|
| 2520 | * |
---|
| 2521 | * @note Lots of sync requests will skew this timer. It should be based |
---|
| 2522 | * on TOD to be accurate. Does it matter ? |
---|
| 2523 | */ |
---|
| 2524 | if (sync_active) |
---|
| 2525 | bd->hold_timer = 0; |
---|
| 2526 | |
---|
| 2527 | if (bd->hold_timer) |
---|
| 2528 | { |
---|
| 2529 | if (update_timers) |
---|
| 2530 | { |
---|
| 2531 | if (bd->hold_timer > timer_delta) |
---|
| 2532 | bd->hold_timer -= timer_delta; |
---|
| 2533 | else |
---|
| 2534 | bd->hold_timer = 0; |
---|
| 2535 | } |
---|
| 2536 | |
---|
| 2537 | if (bd->hold_timer) |
---|
| 2538 | { |
---|
| 2539 | node = node->next; |
---|
| 2540 | continue; |
---|
| 2541 | } |
---|
| 2542 | } |
---|
| 2543 | |
---|
| 2544 | /* |
---|
| 2545 | * This assumes we can set dev_t to -1 which is just an |
---|
| 2546 | * assumption. Cannot use the transfer list being empty the sync dev |
---|
| 2547 | * calls sets the dev to use. |
---|
| 2548 | */ |
---|
| 2549 | if (*dev == (dev_t)-1) |
---|
| 2550 | *dev = bd->dev; |
---|
| 2551 | |
---|
| 2552 | if (bd->dev == *dev) |
---|
| 2553 | { |
---|
| 2554 | rtems_chain_node* next_node = node->next; |
---|
| 2555 | rtems_chain_node* tnode = rtems_chain_tail (transfer); |
---|
| 2556 | |
---|
| 2557 | /* |
---|
| 2558 | * The blocks on the transfer list are sorted in block order. This |
---|
| 2559 | * means multi-block transfers for drivers that require consecutive |
---|
| 2560 | * blocks perform better with sorted blocks and for real disks it may |
---|
| 2561 | * help lower head movement. |
---|
| 2562 | */ |
---|
| 2563 | |
---|
| 2564 | bd->state = RTEMS_BDBUF_STATE_TRANSFER; |
---|
| 2565 | |
---|
| 2566 | rtems_chain_extract (node); |
---|
| 2567 | |
---|
| 2568 | tnode = tnode->previous; |
---|
| 2569 | |
---|
| 2570 | while (node && !rtems_chain_is_head (transfer, tnode)) |
---|
| 2571 | { |
---|
| 2572 | rtems_bdbuf_buffer* tbd = (rtems_bdbuf_buffer*) tnode; |
---|
| 2573 | |
---|
| 2574 | if (bd->block > tbd->block) |
---|
| 2575 | { |
---|
| 2576 | rtems_chain_insert (tnode, node); |
---|
| 2577 | node = NULL; |
---|
| 2578 | } |
---|
| 2579 | else |
---|
| 2580 | tnode = tnode->previous; |
---|
| 2581 | } |
---|
| 2582 | |
---|
| 2583 | if (node) |
---|
| 2584 | rtems_chain_prepend (transfer, node); |
---|
| 2585 | |
---|
| 2586 | node = next_node; |
---|
| 2587 | } |
---|
| 2588 | else |
---|
| 2589 | { |
---|
| 2590 | node = node->next; |
---|
| 2591 | } |
---|
| 2592 | } |
---|
| 2593 | } |
---|
| 2594 | } |
---|
| 2595 | |
---|
| 2596 | /** |
---|
| 2597 | * Process the cache's modified buffers. Check the sync list first then the |
---|
| 2598 | * modified list extracting the buffers suitable to be written to disk. We have |
---|
| 2599 | * a device at a time. The task level loop will repeat this operation while |
---|
| 2600 | * there are buffers to be written. If the transfer fails place the buffers |
---|
| 2601 | * back on the modified list and try again later. The cache is unlocked while |
---|
| 2602 | * the buffers are being written to disk. |
---|
| 2603 | * |
---|
| 2604 | * @param timer_delta It update_timers is true update the timers by this |
---|
| 2605 | * amount. |
---|
| 2606 | * @param update_timers If true update the timers. |
---|
| 2607 | * @param transfer The transfer transaction data. |
---|
| 2608 | * |
---|
| 2609 | * @retval true Buffers where written to disk so scan again. |
---|
| 2610 | * @retval false No buffers where written to disk. |
---|
| 2611 | */ |
---|
| 2612 | static bool |
---|
| 2613 | rtems_bdbuf_swapout_processing (unsigned long timer_delta, |
---|
| 2614 | bool update_timers, |
---|
| 2615 | rtems_bdbuf_swapout_transfer* transfer) |
---|
| 2616 | { |
---|
| 2617 | rtems_bdbuf_swapout_worker* worker; |
---|
| 2618 | bool transfered_buffers = false; |
---|
| 2619 | |
---|
| 2620 | rtems_bdbuf_lock_cache (); |
---|
| 2621 | |
---|
| 2622 | /* |
---|
| 2623 | * If a sync is active do not use a worker because the current code does not |
---|
| 2624 | * cleaning up after. We need to know the buffers have been written when |
---|
[eb649786] | 2625 | * syncing to the release sync lock and currently worker threads do not |
---|
| 2626 | * return to here. We do not know the worker is the last in a sequence of |
---|
| 2627 | * sync writes until after we have it running so we do not know to tell it to |
---|
| 2628 | * release the lock. The simplest solution is to get the main swap out task |
---|
| 2629 | * perform all sync operations. |
---|
[0d15414e] | 2630 | */ |
---|
| 2631 | if (bdbuf_cache.sync_active) |
---|
| 2632 | worker = NULL; |
---|
| 2633 | else |
---|
| 2634 | { |
---|
| 2635 | worker = (rtems_bdbuf_swapout_worker*) |
---|
| 2636 | rtems_chain_get (&bdbuf_cache.swapout_workers); |
---|
| 2637 | if (worker) |
---|
| 2638 | transfer = &worker->transfer; |
---|
[3899a537] | 2639 | } |
---|
[0d15414e] | 2640 | |
---|
| 2641 | rtems_chain_initialize_empty (&transfer->bds); |
---|
| 2642 | transfer->dev = -1; |
---|
| 2643 | |
---|
| 2644 | /* |
---|
| 2645 | * When the sync is for a device limit the sync to that device. If the sync |
---|
| 2646 | * is for a buffer handle process the devices in the order on the sync |
---|
| 2647 | * list. This means the dev is -1. |
---|
| 2648 | */ |
---|
| 2649 | if (bdbuf_cache.sync_active) |
---|
| 2650 | transfer->dev = bdbuf_cache.sync_device; |
---|
| 2651 | |
---|
| 2652 | /* |
---|
| 2653 | * If we have any buffers in the sync queue move them to the modified |
---|
| 2654 | * list. The first sync buffer will select the device we use. |
---|
| 2655 | */ |
---|
| 2656 | rtems_bdbuf_swapout_modified_processing (&transfer->dev, |
---|
| 2657 | &bdbuf_cache.sync, |
---|
| 2658 | &transfer->bds, |
---|
| 2659 | true, false, |
---|
| 2660 | timer_delta); |
---|
| 2661 | |
---|
| 2662 | /* |
---|
| 2663 | * Process the cache's modified list. |
---|
| 2664 | */ |
---|
| 2665 | rtems_bdbuf_swapout_modified_processing (&transfer->dev, |
---|
| 2666 | &bdbuf_cache.modified, |
---|
| 2667 | &transfer->bds, |
---|
| 2668 | bdbuf_cache.sync_active, |
---|
| 2669 | update_timers, |
---|
| 2670 | timer_delta); |
---|
[3899a537] | 2671 | |
---|
[0d15414e] | 2672 | /* |
---|
| 2673 | * We have all the buffers that have been modified for this device so the |
---|
| 2674 | * cache can be unlocked because the state of each buffer has been set to |
---|
| 2675 | * TRANSFER. |
---|
| 2676 | */ |
---|
| 2677 | rtems_bdbuf_unlock_cache (); |
---|
| 2678 | |
---|
| 2679 | /* |
---|
| 2680 | * If there are buffers to transfer to the media transfer them. |
---|
| 2681 | */ |
---|
| 2682 | if (!rtems_chain_is_empty (&transfer->bds)) |
---|
| 2683 | { |
---|
| 2684 | if (worker) |
---|
| 2685 | { |
---|
| 2686 | rtems_status_code sc = rtems_event_send (worker->id, |
---|
| 2687 | RTEMS_BDBUF_SWAPOUT_SYNC); |
---|
| 2688 | if (sc != RTEMS_SUCCESSFUL) |
---|
| 2689 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_SO_WAKE); |
---|
| 2690 | } |
---|
| 2691 | else |
---|
| 2692 | { |
---|
| 2693 | rtems_bdbuf_swapout_write (transfer); |
---|
| 2694 | } |
---|
| 2695 | |
---|
| 2696 | transfered_buffers = true; |
---|
| 2697 | } |
---|
| 2698 | |
---|
| 2699 | if (bdbuf_cache.sync_active && !transfered_buffers) |
---|
[c21c850e] | 2700 | { |
---|
[0d15414e] | 2701 | rtems_id sync_requester; |
---|
| 2702 | rtems_bdbuf_lock_cache (); |
---|
| 2703 | sync_requester = bdbuf_cache.sync_requester; |
---|
| 2704 | bdbuf_cache.sync_active = false; |
---|
| 2705 | bdbuf_cache.sync_requester = 0; |
---|
| 2706 | rtems_bdbuf_unlock_cache (); |
---|
[c21c850e] | 2707 | if (sync_requester) |
---|
| 2708 | rtems_event_send (sync_requester, RTEMS_BDBUF_TRANSFER_SYNC); |
---|
| 2709 | } |
---|
[3899a537] | 2710 | |
---|
[0d15414e] | 2711 | return transfered_buffers; |
---|
[e51bd96] | 2712 | } |
---|
| 2713 | |
---|
[3899a537] | 2714 | /** |
---|
[0d15414e] | 2715 | * Allocate the write request and initialise it for good measure. |
---|
[c21c850e] | 2716 | * |
---|
[0d15414e] | 2717 | * @return rtems_blkdev_request* The write reference memory. |
---|
[e51bd96] | 2718 | */ |
---|
[0d15414e] | 2719 | static rtems_blkdev_request* |
---|
| 2720 | rtems_bdbuf_swapout_writereq_alloc (void) |
---|
[e51bd96] | 2721 | { |
---|
[3899a537] | 2722 | /* |
---|
| 2723 | * @note chrisj The rtems_blkdev_request and the array at the end is a hack. |
---|
| 2724 | * I am disappointment at finding code like this in RTEMS. The request should |
---|
| 2725 | * have been a rtems_chain_control. Simple, fast and less storage as the node |
---|
| 2726 | * is already part of the buffer structure. |
---|
| 2727 | */ |
---|
[0d15414e] | 2728 | rtems_blkdev_request* write_req = |
---|
[3899a537] | 2729 | malloc (sizeof (rtems_blkdev_request) + |
---|
| 2730 | (rtems_bdbuf_configuration.max_write_blocks * |
---|
| 2731 | sizeof (rtems_blkdev_sg_buffer))); |
---|
| 2732 | |
---|
| 2733 | if (!write_req) |
---|
| 2734 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_SO_NOMEM); |
---|
| 2735 | |
---|
| 2736 | write_req->req = RTEMS_BLKDEV_REQ_WRITE; |
---|
| 2737 | write_req->req_done = rtems_bdbuf_write_done; |
---|
| 2738 | write_req->done_arg = write_req; |
---|
| 2739 | write_req->io_task = rtems_task_self (); |
---|
| 2740 | |
---|
[0d15414e] | 2741 | return write_req; |
---|
| 2742 | } |
---|
| 2743 | |
---|
| 2744 | /** |
---|
| 2745 | * The swapout worker thread body. |
---|
| 2746 | * |
---|
| 2747 | * @param arg A pointer to the worker thread's private data. |
---|
| 2748 | * @return rtems_task Not used. |
---|
| 2749 | */ |
---|
| 2750 | static rtems_task |
---|
| 2751 | rtems_bdbuf_swapout_worker_task (rtems_task_argument arg) |
---|
| 2752 | { |
---|
| 2753 | rtems_bdbuf_swapout_worker* worker = (rtems_bdbuf_swapout_worker*) arg; |
---|
| 2754 | |
---|
| 2755 | while (worker->enabled) |
---|
| 2756 | { |
---|
| 2757 | rtems_event_set out; |
---|
| 2758 | rtems_status_code sc; |
---|
| 2759 | |
---|
| 2760 | sc = rtems_event_receive (RTEMS_BDBUF_SWAPOUT_SYNC, |
---|
| 2761 | RTEMS_EVENT_ALL | RTEMS_WAIT, |
---|
| 2762 | RTEMS_NO_TIMEOUT, |
---|
| 2763 | &out); |
---|
| 2764 | |
---|
| 2765 | if (sc != RTEMS_SUCCESSFUL) |
---|
| 2766 | rtems_fatal_error_occurred (BLKDEV_FATAL_BDBUF_SWAPOUT_RE); |
---|
| 2767 | |
---|
| 2768 | rtems_bdbuf_swapout_write (&worker->transfer); |
---|
| 2769 | |
---|
| 2770 | rtems_bdbuf_lock_cache (); |
---|
| 2771 | |
---|
| 2772 | rtems_chain_initialize_empty (&worker->transfer.bds); |
---|
| 2773 | worker->transfer.dev = -1; |
---|
| 2774 | |
---|
| 2775 | rtems_chain_append (&bdbuf_cache.swapout_workers, &worker->link); |
---|
| 2776 | |
---|
| 2777 | rtems_bdbuf_unlock_cache (); |
---|
| 2778 | } |
---|
| 2779 | |
---|
| 2780 | free (worker->transfer.write_req); |
---|
| 2781 | free (worker); |
---|
| 2782 | |
---|
| 2783 | rtems_task_delete (RTEMS_SELF); |
---|
| 2784 | } |
---|
| 2785 | |
---|
| 2786 | /** |
---|
| 2787 | * Open the swapout worker threads. |
---|
| 2788 | */ |
---|
| 2789 | static void |
---|
| 2790 | rtems_bdbuf_swapout_workers_open (void) |
---|
| 2791 | { |
---|
| 2792 | rtems_status_code sc; |
---|
| 2793 | int w; |
---|
| 2794 | |
---|
| 2795 | rtems_bdbuf_lock_cache (); |
---|
| 2796 | |
---|
| 2797 | for (w = 0; w < rtems_bdbuf_configuration.swapout_workers; w++) |
---|
| 2798 | { |
---|
| 2799 | rtems_bdbuf_swapout_worker* worker; |
---|
| 2800 | |
---|
| 2801 | worker = malloc (sizeof (rtems_bdbuf_swapout_worker)); |
---|
| 2802 | if (!worker) |
---|
| 2803 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_SO_NOMEM); |
---|
| 2804 | |
---|
| 2805 | rtems_chain_append (&bdbuf_cache.swapout_workers, &worker->link); |
---|
| 2806 | worker->enabled = true; |
---|
| 2807 | worker->transfer.write_req = rtems_bdbuf_swapout_writereq_alloc (); |
---|
| 2808 | |
---|
| 2809 | rtems_chain_initialize_empty (&worker->transfer.bds); |
---|
| 2810 | worker->transfer.dev = -1; |
---|
| 2811 | |
---|
| 2812 | sc = rtems_task_create (rtems_build_name('B', 'D', 'o', 'a' + w), |
---|
| 2813 | (rtems_bdbuf_configuration.swapout_priority ? |
---|
| 2814 | rtems_bdbuf_configuration.swapout_priority : |
---|
| 2815 | RTEMS_BDBUF_SWAPOUT_TASK_PRIORITY_DEFAULT), |
---|
| 2816 | SWAPOUT_TASK_STACK_SIZE, |
---|
| 2817 | RTEMS_PREEMPT | RTEMS_NO_TIMESLICE | RTEMS_NO_ASR, |
---|
| 2818 | RTEMS_LOCAL | RTEMS_NO_FLOATING_POINT, |
---|
| 2819 | &worker->id); |
---|
| 2820 | if (sc != RTEMS_SUCCESSFUL) |
---|
| 2821 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_SO_WK_CREATE); |
---|
| 2822 | |
---|
| 2823 | sc = rtems_task_start (worker->id, |
---|
| 2824 | rtems_bdbuf_swapout_worker_task, |
---|
| 2825 | (rtems_task_argument) worker); |
---|
| 2826 | if (sc != RTEMS_SUCCESSFUL) |
---|
| 2827 | rtems_fatal_error_occurred (RTEMS_BLKDEV_FATAL_BDBUF_SO_WK_START); |
---|
| 2828 | } |
---|
| 2829 | |
---|
| 2830 | rtems_bdbuf_unlock_cache (); |
---|
| 2831 | } |
---|
| 2832 | |
---|
| 2833 | /** |
---|
| 2834 | * Close the swapout worker threads. |
---|
| 2835 | */ |
---|
| 2836 | static void |
---|
| 2837 | rtems_bdbuf_swapout_workers_close (void) |
---|
| 2838 | { |
---|
| 2839 | rtems_chain_node* node; |
---|
| 2840 | |
---|
| 2841 | rtems_bdbuf_lock_cache (); |
---|
| 2842 | |
---|
| 2843 | node = rtems_chain_first (&bdbuf_cache.swapout_workers); |
---|
| 2844 | while (!rtems_chain_is_tail (&bdbuf_cache.swapout_workers, node)) |
---|
| 2845 | { |
---|
| 2846 | rtems_bdbuf_swapout_worker* worker = (rtems_bdbuf_swapout_worker*) node; |
---|
| 2847 | worker->enabled = false; |
---|
| 2848 | rtems_event_send (worker->id, RTEMS_BDBUF_SWAPOUT_SYNC); |
---|
| 2849 | node = rtems_chain_next (node); |
---|
| 2850 | } |
---|
| 2851 | |
---|
| 2852 | rtems_bdbuf_unlock_cache (); |
---|
| 2853 | } |
---|
| 2854 | |
---|
| 2855 | /** |
---|
| 2856 | * Body of task which takes care on flushing modified buffers to the disk. |
---|
| 2857 | * |
---|
| 2858 | * @param arg A pointer to the global cache data. Use the global variable and |
---|
| 2859 | * not this. |
---|
| 2860 | * @return rtems_task Not used. |
---|
| 2861 | */ |
---|
| 2862 | static rtems_task |
---|
| 2863 | rtems_bdbuf_swapout_task (rtems_task_argument arg) |
---|
| 2864 | { |
---|
| 2865 | rtems_bdbuf_swapout_transfer transfer; |
---|
| 2866 | uint32_t period_in_ticks; |
---|
| 2867 | const uint32_t period_in_msecs = bdbuf_config.swapout_period;; |
---|
| 2868 | uint32_t timer_delta; |
---|
| 2869 | |
---|
| 2870 | transfer.write_req = rtems_bdbuf_swapout_writereq_alloc (); |
---|
| 2871 | rtems_chain_initialize_empty (&transfer.bds); |
---|
| 2872 | transfer.dev = -1; |
---|
| 2873 | |
---|
| 2874 | /* |
---|
| 2875 | * Localise the period. |
---|
| 2876 | */ |
---|
[26fb4aa] | 2877 | period_in_ticks = RTEMS_MICROSECONDS_TO_TICKS (period_in_msecs * 1000); |
---|
[3899a537] | 2878 | |
---|
| 2879 | /* |
---|
[c21c850e] | 2880 | * This is temporary. Needs to be changed to use the real time clock. |
---|
[3899a537] | 2881 | */ |
---|
| 2882 | timer_delta = period_in_msecs; |
---|
| 2883 | |
---|
[0d15414e] | 2884 | /* |
---|
| 2885 | * Create the worker threads. |
---|
| 2886 | */ |
---|
| 2887 | rtems_bdbuf_swapout_workers_open (); |
---|
| 2888 | |
---|
| 2889 | while (bdbuf_cache.swapout_enabled) |
---|
[3899a537] | 2890 | { |
---|
[0d15414e] | 2891 | rtems_event_set out; |
---|
| 2892 | rtems_status_code sc; |
---|
[e51bd96] | 2893 | |
---|
[0ebfac19] | 2894 | /* |
---|
[3899a537] | 2895 | * Only update the timers once in the processing cycle. |
---|
| 2896 | */ |
---|
[4f971343] | 2897 | bool update_timers = true; |
---|
[3899a537] | 2898 | |
---|
| 2899 | /* |
---|
[c21c850e] | 2900 | * If we write buffers to any disk perform a check again. We only write a |
---|
[0d15414e] | 2901 | * single device at a time and the cache may have more than one device's |
---|
[c21c850e] | 2902 | * buffers modified waiting to be written. |
---|
[0ebfac19] | 2903 | */ |
---|
[4f971343] | 2904 | bool transfered_buffers; |
---|
[3899a537] | 2905 | |
---|
| 2906 | do |
---|
[e51bd96] | 2907 | { |
---|
[4f971343] | 2908 | transfered_buffers = false; |
---|
[3899a537] | 2909 | |
---|
| 2910 | /* |
---|
[0d15414e] | 2911 | * Extact all the buffers we find for a specific device. The device is |
---|
| 2912 | * the first one we find on a modified list. Process the sync queue of |
---|
| 2913 | * buffers first. |
---|
[3899a537] | 2914 | */ |
---|
[0d15414e] | 2915 | if (rtems_bdbuf_swapout_processing (timer_delta, |
---|
| 2916 | update_timers, |
---|
| 2917 | &transfer)) |
---|
[3899a537] | 2918 | { |
---|
[0d15414e] | 2919 | transfered_buffers = true; |
---|
[3899a537] | 2920 | } |
---|
[0d15414e] | 2921 | |
---|
[3899a537] | 2922 | /* |
---|
| 2923 | * Only update the timers once. |
---|
| 2924 | */ |
---|
[4f971343] | 2925 | update_timers = false; |
---|
[e51bd96] | 2926 | } |
---|
[3899a537] | 2927 | while (transfered_buffers); |
---|
| 2928 | |
---|
| 2929 | sc = rtems_event_receive (RTEMS_BDBUF_SWAPOUT_SYNC, |
---|
| 2930 | RTEMS_EVENT_ALL | RTEMS_WAIT, |
---|
| 2931 | period_in_ticks, |
---|
| 2932 | &out); |
---|
| 2933 | |
---|
| 2934 | if ((sc != RTEMS_SUCCESSFUL) && (sc != RTEMS_TIMEOUT)) |
---|
| 2935 | rtems_fatal_error_occurred (BLKDEV_FATAL_BDBUF_SWAPOUT_RE); |
---|
| 2936 | } |
---|
| 2937 | |
---|
[0d15414e] | 2938 | rtems_bdbuf_swapout_workers_close (); |
---|
| 2939 | |
---|
| 2940 | free (transfer.write_req); |
---|
[3899a537] | 2941 | |
---|
| 2942 | rtems_task_delete (RTEMS_SELF); |
---|
[e51bd96] | 2943 | } |
---|
| 2944 | |
---|